Merge branch 'master' into bael-16656

spring-boot/src/main/java/com/baeldung/annotation/servletcomponentscan/SpringBootAnnotatedApp.java

@@ -0,0 +1,25 @@
+package com.baeldung.annotation.servletcomponentscan;
+
+import org.springframework.boot.SpringApplication;
+import org.springframework.boot.autoconfigure.SpringBootApplication;
+import org.springframework.boot.web.servlet.ServletComponentScan;
+
+/**
+ * using the following annotations are equivalent:
+ * <ul><li>
+ * <code>@ServletComponentScan</code>
+ * </li><li>
+ * <code>@ServletComponentScan(basePackages = "com.baeldung.annotation.servletcomponentscan.components")</code>
+ * </li><li>
+ * <code>@ServletComponentScan(basePackageClasses = {AttrListener.class, HelloFilter.class, HelloServlet.class, EchoServlet.class})</code>
+ * </li></ul>
+ */
+@SpringBootApplication
+@ServletComponentScan("com.baeldung.annotation.servletcomponentscan.components")
+public class SpringBootAnnotatedApp {
+
+    public static void main(String[] args) {
+        SpringApplication.run(SpringBootAnnotatedApp.class, args);
+    }
+
+}

spring-boot/src/main/java/com/baeldung/annotation/servletcomponentscan/SpringBootPlainApp.java

@@ -0,0 +1,13 @@
+package com.baeldung.annotation.servletcomponentscan;
+
+import org.springframework.boot.autoconfigure.SpringBootApplication;
+import org.springframework.context.annotation.ComponentScan;
+
+@SpringBootApplication
+@ComponentScan(basePackages = "com.baeldung.annotation.servletcomponentscan.components")
+public class SpringBootPlainApp {
+
+    public static void main(String[] args) {
+    }
+
+}

spring-boot/src/main/java/com/baeldung/annotation/servletcomponentscan/components/AttrListener.java

@@ -0,0 +1,21 @@
+package com.baeldung.annotation.servletcomponentscan.components;
+
+import javax.servlet.ServletContextEvent;
+import javax.servlet.ServletContextListener;
+import javax.servlet.annotation.WebListener;
+
+@WebListener
+public class AttrListener implements ServletContextListener {
+
+    @Override
+    public void contextInitialized(ServletContextEvent servletContextEvent) {
+        servletContextEvent.getServletContext().setAttribute("servlet-context-attr", "test");
+        System.out.println("context init");
+    }
+
+    @Override
+    public void contextDestroyed(ServletContextEvent servletContextEvent) {
+        System.out.println("context destroy");
+    }
+
+}

spring-boot/src/main/java/com/baeldung/annotation/servletcomponentscan/components/EchoServlet.java

@@ -0,0 +1,27 @@
+package com.baeldung.annotation.servletcomponentscan.components;
+
+import javax.servlet.annotation.WebServlet;
+import javax.servlet.http.HttpServlet;
+import javax.servlet.http.HttpServletRequest;
+import javax.servlet.http.HttpServletResponse;
+import java.io.File;
+import java.io.IOException;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.nio.file.StandardCopyOption;
+
+@WebServlet(name = "echo servlet", urlPatterns = "/echo")
+public class EchoServlet extends HttpServlet {
+
+    @Override
+    public void doPost(HttpServletRequest request, HttpServletResponse response) {
+        try {
+            Path path = File.createTempFile("echo", "tmp").toPath();
+            Files.copy(request.getInputStream(), path, StandardCopyOption.REPLACE_EXISTING);
+            Files.copy(path, response.getOutputStream());
+            Files.delete(path);
+        } catch (IOException e) {
+            e.printStackTrace();
+        }
+    }
+}

spring-boot/src/main/java/com/baeldung/annotation/servletcomponentscan/components/HelloFilter.java

@@ -0,0 +1,30 @@
+package com.baeldung.annotation.servletcomponentscan.components;
+
+import javax.servlet.*;
+import javax.servlet.annotation.WebFilter;
+import javax.servlet.annotation.WebInitParam;
+import java.io.IOException;
+
+@WebFilter(urlPatterns = "/hello", description = "a filter for hello servlet", initParams = { @WebInitParam(name = "msg", value = "filtering ") }, filterName = "hello filter", servletNames = { "echo servlet" })
+public class HelloFilter implements Filter {
+
+    private FilterConfig filterConfig;
+
+    @Override
+    public void init(FilterConfig filterConfig) throws ServletException {
+        System.out.println("filter init");
+        this.filterConfig = filterConfig;
+    }
+
+    @Override
+    public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain) throws IOException, ServletException {
+        servletResponse.getOutputStream().print(filterConfig.getInitParameter("msg"));
+        filterChain.doFilter(servletRequest, servletResponse);
+    }
+
+    @Override
+    public void destroy() {
+        System.out.println("filter destroy");
+    }
+
+}

spring-boot/src/main/java/com/baeldung/annotation/servletcomponentscan/components/HelloServlet.java

@@ -0,0 +1,30 @@
+package com.baeldung.annotation.servletcomponentscan.components;
+
+import javax.servlet.ServletConfig;
+import javax.servlet.annotation.WebInitParam;
+import javax.servlet.annotation.WebServlet;
+import javax.servlet.http.HttpServlet;
+import javax.servlet.http.HttpServletRequest;
+import javax.servlet.http.HttpServletResponse;
+import java.io.IOException;
+
+@WebServlet(urlPatterns = "/hello", initParams = { @WebInitParam(name = "msg", value = "hello") })
+public class HelloServlet extends HttpServlet {
+
+    private ServletConfig servletConfig;
+
+    @Override
+    public void init(ServletConfig servletConfig) {
+        this.servletConfig = servletConfig;
+    }
+
+    @Override
+    public void doGet(HttpServletRequest request, HttpServletResponse response) {
+        try {
+            response.getOutputStream().write(servletConfig.getInitParameter("msg").getBytes());
+        } catch (IOException e) {
+            e.printStackTrace();
+        }
+    }
+
+}

spring-boot/src/main/java/com/baeldung/beanvalidation/application/Application.java

@@ -0,0 +1,28 @@
+package com.baeldung.beanvalidation.application;
+
+import com.baeldung.beanvalidation.application.entities.User;
+import com.baeldung.beanvalidation.application.repositories.UserRepository;
+
+import org.springframework.boot.CommandLineRunner;
+import org.springframework.boot.SpringApplication;
+import org.springframework.boot.autoconfigure.SpringBootApplication;
+import org.springframework.context.annotation.Bean;
+
+@SpringBootApplication
+public class Application {
+    
+    public static void main(String[] args) {
+        SpringApplication.run(Application.class, args);
+    }
+    
+    @Bean
+    public CommandLineRunner run(UserRepository userRepository) throws Exception {
+        return (String[] args) -> {
+            User user1 = new User("Bob", "bob@domain.com");
+            User user2 = new User("Jenny", "jenny@domain.com");
+            userRepository.save(user1);
+            userRepository.save(user2);
+            userRepository.findAll().forEach(System.out::println);
+        };
+    }
+}

spring-boot/src/main/java/com/baeldung/beanvalidation/application/controllers/UserController.java

@@ -0,0 +1,53 @@
+package com.baeldung.beanvalidation.application.controllers;
+
+import com.baeldung.beanvalidation.application.entities.User;
+import com.baeldung.beanvalidation.application.repositories.UserRepository;
+
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+import javax.validation.Valid;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.http.HttpStatus;
+import org.springframework.http.ResponseEntity;
+import org.springframework.validation.FieldError;
+import org.springframework.web.bind.MethodArgumentNotValidException;
+import org.springframework.web.bind.annotation.ExceptionHandler;
+import org.springframework.web.bind.annotation.GetMapping;
+import org.springframework.web.bind.annotation.PostMapping;
+import org.springframework.web.bind.annotation.RequestBody;
+import org.springframework.web.bind.annotation.ResponseStatus;
+import org.springframework.web.bind.annotation.RestController;
+
+@RestController
+public class UserController {
+
+    private final UserRepository userRepository;
+
+    @Autowired
+    public UserController(UserRepository userRepository) {
+        this.userRepository = userRepository;
+    }
+
+    @GetMapping("/users")
+    public List<User> getUsers() {
+        return (List<User>) userRepository.findAll();
+    }
+
+    @PostMapping("/users")
+    ResponseEntity<String> addUser(@Valid @RequestBody User user) {
+        return ResponseEntity.ok("User is valid");
+    }
+    
+    @ResponseStatus(HttpStatus.BAD_REQUEST)
+    @ExceptionHandler(MethodArgumentNotValidException.class)
+    public Map<String, String> handleValidationExceptions(MethodArgumentNotValidException ex) {
+        Map<String, String> errors = new HashMap<>();
+        ex.getBindingResult().getAllErrors().forEach((error) -> {
+            String fieldName = ((FieldError) error).getField();
+            String errorMessage = error.getDefaultMessage();
+            errors.put(fieldName, errorMessage);
+        });
+        return errors;
+    }
+}

spring-boot/src/main/java/com/baeldung/beanvalidation/application/entities/User.java

@@ -0,0 +1,50 @@
+package com.baeldung.beanvalidation.application.entities;
+
+import javax.persistence.Entity;
+import javax.persistence.GeneratedValue;
+import javax.persistence.GenerationType;
+import javax.persistence.Id;
+import javax.persistence.Table;
+import javax.validation.constraints.NotBlank;
+
+@Entity
+public class User {
+    
+    @Id
+    @GeneratedValue(strategy = GenerationType.AUTO)
+    private long id;
+    
+    @NotBlank(message = "Name is mandatory")
+    private String name;
+    
+    @NotBlank(message = "Email is mandatory")
+    private String email;
+    
+    public User(){}
+    
+    public User(String name, String email) {
+        this.name = name;
+        this.email = email;
+    }
+    
+    public String getName() {
+        return name;
+    }
+
+    public void setName(String name) {
+        this.name = name;
+    }
+
+    public String getEmail() {
+        return email;
+    }
+
+    public void setEmail(String email) {
+        this.email = email;
+    }
+
+    @Override
+    public String toString() {
+        return "User{" + "id=" + id + ", name=" + name + ", email=" + email + '}';
+    }    
+}

spring-boot/src/main/java/com/baeldung/beanvalidation/application/repositories/UserRepository.java

@@ -0,0 +1,9 @@
+package com.baeldung.beanvalidation.application.repositories;
+
+import org.springframework.data.repository.CrudRepository;
+import org.springframework.stereotype.Repository;
+
+import com.baeldung.beanvalidation.application.entities.User;
+
+@Repository
+public interface UserRepository extends CrudRepository<User, Long> {}

spring-boot/src/main/java/com/baeldung/bootcustomfilters/FilterConfig.java

@@ -0,0 +1,25 @@
+package com.baeldung.bootcustomfilters;
+
+import org.springframework.boot.web.servlet.FilterRegistrationBean;
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+
+import com.baeldung.bootcustomfilters.filters.RequestResponseLoggingFilter;
+
+@Configuration
+public class FilterConfig {
+
+    // uncomment this and comment the @Component in the filter class definition to register only for a url pattern
+    // @Bean
+    public FilterRegistrationBean<RequestResponseLoggingFilter> loggingFilter() {
+        FilterRegistrationBean<RequestResponseLoggingFilter> registrationBean = new FilterRegistrationBean<>();
+
+        registrationBean.setFilter(new RequestResponseLoggingFilter());
+
+        registrationBean.addUrlPatterns("/users/*");
+
+        return registrationBean;
+
+    }
+
+}

spring-boot/src/main/java/com/baeldung/bootcustomfilters/SpringBootFiltersApplication.java

@@ -0,0 +1,17 @@
+package com.baeldung.bootcustomfilters;
+
+import org.springframework.boot.SpringApplication;
+import org.springframework.boot.autoconfigure.SpringBootApplication;
+
+/**
+ * Boot application
+ * @author hemant
+ *
+ */
+@SpringBootApplication
+public class SpringBootFiltersApplication {
+
+	public static void main(String[] args) {
+		SpringApplication.run(SpringBootFiltersApplication.class, args);
+	}
+}

spring-boot/src/main/java/com/baeldung/bootcustomfilters/controller/UserController.java

@@ -0,0 +1,35 @@
+package com.baeldung.bootcustomfilters.controller;
+
+import java.util.Arrays;
+import java.util.List;
+import java.util.UUID;
+
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+import org.springframework.web.bind.annotation.GetMapping;
+import org.springframework.web.bind.annotation.RequestMapping;
+import org.springframework.web.bind.annotation.RestController;
+
+import com.baeldung.bootcustomfilters.model.User;
+
+/**
+ * Rest controller for User
+ * @author hemant
+ *
+ */
+@RestController
+@RequestMapping("/users")
+public class UserController {
+
+	private static final Logger LOG = LoggerFactory.getLogger(UserController.class);
+
+	@GetMapping("")
+	public List<User> getAllUsers() {
+		LOG.info("Fetching all the users");
+		return Arrays.asList(
+				new User(UUID.randomUUID().toString(), "User1", "user1@test.com"),
+				new User(UUID.randomUUID().toString(), "User1", "user1@test.com"),
+				new User(UUID.randomUUID().toString(), "User1", "user1@test.com"));
+	}
+
+}

spring-boot/src/main/java/com/baeldung/bootcustomfilters/filters/RequestResponseLoggingFilter.java

@@ -0,0 +1,50 @@
+package com.baeldung.bootcustomfilters.filters;
+
+import java.io.IOException;
+
+import javax.servlet.Filter;
+import javax.servlet.FilterChain;
+import javax.servlet.FilterConfig;
+import javax.servlet.ServletException;
+import javax.servlet.ServletRequest;
+import javax.servlet.ServletResponse;
+import javax.servlet.http.HttpServletRequest;
+import javax.servlet.http.HttpServletResponse;
+
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+import org.springframework.core.annotation.Order;
+import org.springframework.stereotype.Component;
+
+/**
+ * A servlet filter to log request and response
+ * The logging implementation is pretty native and for demonstration only
+ * @author hemant
+ *
+ */
+@Component
+@Order(2)
+public class RequestResponseLoggingFilter implements Filter {
+
+	private final static Logger LOG = LoggerFactory.getLogger(RequestResponseLoggingFilter.class);
+
+	@Override
+	public void init(final FilterConfig filterConfig) throws ServletException {
+		LOG.info("Initializing filter :{}", this);
+	}
+
+	@Override
+	public void doFilter(final ServletRequest request, final ServletResponse response, final FilterChain chain)
+			throws IOException, ServletException {
+		HttpServletRequest req = (HttpServletRequest) request;
+		HttpServletResponse res = (HttpServletResponse) response;
+		LOG.info("Logging Request  {} : {}", req.getMethod(), req.getRequestURI());
+		chain.doFilter(request, response);
+		LOG.info("Logging Response :{}", res.getContentType());
+	}
+
+	@Override
+	public void destroy() {
+		LOG.warn("Destructing filter :{}", this);
+	}
+}

spring-boot/src/main/java/com/baeldung/bootcustomfilters/filters/TransactionFilter.java

@@ -0,0 +1,47 @@
+package com.baeldung.bootcustomfilters.filters;
+
+import java.io.IOException;
+
+import javax.servlet.Filter;
+import javax.servlet.FilterChain;
+import javax.servlet.FilterConfig;
+import javax.servlet.ServletException;
+import javax.servlet.ServletRequest;
+import javax.servlet.ServletResponse;
+import javax.servlet.http.HttpServletRequest;
+
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+import org.springframework.core.annotation.Order;
+import org.springframework.stereotype.Component;
+
+/**
+ * A filter to create transaction before and commit it once request completes
+ * The current implemenatation is just for demo
+ * @author hemant
+ *
+ */
+@Component
+@Order(1)
+public class TransactionFilter implements Filter {
+
+	private final static Logger LOG = LoggerFactory.getLogger(TransactionFilter.class);
+
+	@Override
+	public void init(final FilterConfig filterConfig) throws ServletException {
+		LOG.info("Initializing filter :{}", this);
+	}
+
+	@Override
+	public void doFilter(final ServletRequest request, final ServletResponse response, final FilterChain chain) throws IOException, ServletException {
+		HttpServletRequest req = (HttpServletRequest) request;
+		LOG.info("Starting Transaction for req :{}", req.getRequestURI());
+		chain.doFilter(request, response);
+		LOG.info("Committing Transaction for req :{}", req.getRequestURI());
+	}
+
+	@Override
+	public void destroy() {
+		LOG.warn("Destructing filter :{}", this);
+	}
+}

spring-boot/src/main/java/com/baeldung/bootcustomfilters/model/User.java

@@ -0,0 +1,45 @@
+package com.baeldung.bootcustomfilters.model;
+
+/**
+ * User model
+ * @author hemant
+ *
+ */
+public class User {
+
+	private String id;
+	private String name;
+	private String email;
+
+	public User(String id, String name, String email) {
+		super();
+		this.id = id;
+		this.name = name;
+		this.email = email;
+	}
+
+	public String getId() {
+		return id;
+	}
+
+	public void setId(String id) {
+		this.id = id;
+	}
+
+	public String getName() {
+		return name;
+	}
+
+	public void setName(String name) {
+		this.name = name;
+	}
+
+	public String getEmail() {
+		return email;
+	}
+
+	public void setEmail(String email) {
+		this.email = email;
+	}
+
+}

spring-boot/src/main/java/com/baeldung/chaosmonkey/SpringBootChaosMonkeyApp.java

@@ -0,0 +1,15 @@
+package com.baeldung.chaosmonkey;
+
+import org.springframework.boot.SpringApplication;
+import org.springframework.boot.autoconfigure.SpringBootApplication;
+
+/**
+ * Created by adi on 8/2/18.
+ */
+@SpringBootApplication(scanBasePackages = { "com.baeldung.chaosmonkey" })
+public class SpringBootChaosMonkeyApp {
+
+    public static void main(String[] args) {
+        SpringApplication.run(SpringBootChaosMonkeyApp.class, args);
+    }
+}

spring-boot/src/main/java/com/baeldung/chaosmonkey/controller/PermissionsController.java

@@ -0,0 +1,25 @@
+package com.baeldung.chaosmonkey.controller;
+
+import com.baeldung.chaosmonkey.service.PermissionsService;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.web.bind.annotation.GetMapping;
+import org.springframework.web.bind.annotation.RequestMapping;
+import org.springframework.web.bind.annotation.RestController;
+
+import java.util.List;
+
+/**
+ * Created by adi on 8/2/18.
+ */
+@RestController
+@RequestMapping("/permissions")
+public class PermissionsController {
+
+    @Autowired private PermissionsService permissionsService;
+
+    @GetMapping
+    public List<String> getAllPermissions() {
+        return permissionsService.getAllPermissions();
+    }
+
+}

spring-boot/src/main/java/com/baeldung/chaosmonkey/service/PermissionsService.java

@@ -0,0 +1,17 @@
+package com.baeldung.chaosmonkey.service;
+
+import org.springframework.stereotype.Service;
+
+import java.util.Arrays;
+import java.util.List;
+
+/**
+ * Created by adi on 8/2/18.
+ */
+@Service
+public class PermissionsService {
+
+    public List<String> getAllPermissions() {
+        return Arrays.asList("CREATE", "READ", "UPDATE", "DELETE");
+    }
+}

spring-boot/src/main/java/com/baeldung/displayallbeans/Application.java

@@ -0,0 +1,23 @@
+package com.baeldung.displayallbeans;
+
+import org.springframework.boot.SpringApplication;
+import org.springframework.boot.autoconfigure.SpringBootApplication;
+import org.springframework.context.ApplicationContext;
+
+@SpringBootApplication
+public class Application {
+    private static ApplicationContext applicationContext;
+
+    public static void main(String[] args) {
+        applicationContext = SpringApplication.run(Application.class, args);
+
+        displayAllBeans();
+    }
+
+    public static void displayAllBeans() {
+        String[] allBeanNames = applicationContext.getBeanDefinitionNames();
+        for (String beanName : allBeanNames) {
+            System.out.println(beanName);
+        }
+    }
+}

spring-boot/src/main/java/com/baeldung/displayallbeans/controller/FooController.java

@@ -0,0 +1,23 @@
+package com.baeldung.displayallbeans.controller;
+
+import java.util.Map;
+
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.http.ResponseEntity;
+import org.springframework.stereotype.Controller;
+import org.springframework.web.bind.annotation.GetMapping;
+
+import com.baeldung.displayallbeans.service.FooService;
+
+@Controller
+public class FooController {
+    @Autowired
+    private FooService fooService;
+
+    @GetMapping(value = "/displayallbeans")
+    public ResponseEntity<String> getHeaderAndBody(Map<String, Object> model) {
+        model.put("header", fooService.getHeader());
+        model.put("message", fooService.getBody());
+        return ResponseEntity.ok("displayallbeans");
+    }
+}

spring-boot/src/main/java/com/baeldung/displayallbeans/service/FooService.java

@@ -0,0 +1,16 @@
+package com.baeldung.displayallbeans.service;
+
+import org.springframework.stereotype.Service;
+
+@Service
+public class FooService {
+
+    public String getHeader() {
+        return "Display All Beans";
+    }
+
+    public String getBody() {
+        return "This is a sample application that displays all beans " + "in Spring IoC container using ListableBeanFactory interface " + "and Spring Boot Actuators.";
+    }
+
+}

spring-boot/src/main/java/com/baeldung/dynamicvalidation/ContactInfo.java

@@ -0,0 +1,26 @@
+package com.baeldung.dynamicvalidation;
+
+import static java.lang.annotation.ElementType.ANNOTATION_TYPE;
+import static java.lang.annotation.ElementType.CONSTRUCTOR;
+import static java.lang.annotation.ElementType.FIELD;
+import static java.lang.annotation.ElementType.METHOD;
+import static java.lang.annotation.ElementType.PARAMETER;
+
+import java.lang.annotation.Retention;
+import java.lang.annotation.RetentionPolicy;
+import java.lang.annotation.Target;
+
+import javax.validation.Constraint;
+import javax.validation.Payload;
+
+@Constraint(validatedBy = { ContactInfoValidator.class })
+@Target({ METHOD, FIELD, ANNOTATION_TYPE, CONSTRUCTOR, PARAMETER })
+@Retention(RetentionPolicy.RUNTIME)
+public @interface ContactInfo {
+    String message() default "Invalid value";
+
+    Class<?>[] groups() default {};
+
+    Class<? extends Payload>[] payload() default {};
+
+}

spring-boot/src/main/java/com/baeldung/dynamicvalidation/ContactInfoValidator.java

@@ -0,0 +1,46 @@
+package com.baeldung.dynamicvalidation;
+
+import com.baeldung.dynamicvalidation.dao.ContactInfoExpressionRepository;
+import com.baeldung.dynamicvalidation.model.ContactInfoExpression;
+
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.beans.factory.annotation.Value;
+import org.thymeleaf.util.StringUtils;
+
+import javax.validation.ConstraintValidator;
+import javax.validation.ConstraintValidatorContext;
+import java.util.regex.Pattern;
+
+public class ContactInfoValidator implements ConstraintValidator<ContactInfo, String> {
+
+    private static final Logger LOG = LogManager.getLogger(ContactInfoValidator.class);
+
+    @Autowired
+    private ContactInfoExpressionRepository expressionRepository;
+
+    @Value("${contactInfoType}")
+    String expressionType;
+
+    private String pattern;
+
+    @Override
+    public void initialize(final ContactInfo contactInfo) {
+        if (StringUtils.isEmptyOrWhitespace(expressionType)) {
+            LOG.error("Contact info type missing!");
+        } else {
+            pattern = expressionRepository.findById(expressionType).map(ContactInfoExpression::getPattern).orElse("");
+        }
+    }
+
+    @Override
+    public boolean isValid(final String value, final ConstraintValidatorContext context) {
+        if (!StringUtils.isEmptyOrWhitespace(pattern)) {
+            return Pattern.matches(pattern, value);
+        }
+        LOG.error("Contact info pattern missing!");
+        return false;
+    }
+
+}

spring-boot/src/main/java/com/baeldung/dynamicvalidation/DynamicValidationApp.java

@@ -0,0 +1,14 @@
+package com.baeldung.dynamicvalidation;
+
+import javax.annotation.security.RolesAllowed;
+
+import org.springframework.boot.SpringApplication;
+import org.springframework.boot.autoconfigure.SpringBootApplication;
+
+@SpringBootApplication
+public class DynamicValidationApp {
+    @RolesAllowed("*")
+    public static void main(String[] args) {
+        SpringApplication.run(DynamicValidationApp.class, args);
+    }
+}

spring-boot/src/main/java/com/baeldung/dynamicvalidation/config/CustomerController.java

@@ -0,0 +1,29 @@
+package com.baeldung.dynamicvalidation.config;
+
+import javax.validation.Valid;
+
+import org.springframework.stereotype.Controller;
+import org.springframework.ui.Model;
+import org.springframework.validation.BindingResult;
+import org.springframework.web.bind.annotation.GetMapping;
+import org.springframework.web.bind.annotation.PostMapping;
+import com.baeldung.dynamicvalidation.model.Customer;
+
+@Controller
+public class CustomerController {
+
+    @GetMapping("/customer")
+    public String getCustomerPage(Model model) {
+        return "customer";
+    }
+
+    @PostMapping("/customer")
+    public String validateCustomer(@Valid final Customer customer, final BindingResult result, final Model model) {
+        if (result.hasErrors()) {
+            model.addAttribute("message", "The information is invalid!");
+        } else {
+            model.addAttribute("message", "The information is valid!");
+        }
+        return "customer";
+    }
+}

spring-boot/src/main/java/com/baeldung/dynamicvalidation/config/PersistenceConfig.java

@@ -0,0 +1,24 @@
+package com.baeldung.dynamicvalidation.config;
+
+import javax.sql.DataSource;
+
+import org.springframework.boot.autoconfigure.domain.EntityScan;
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+import org.springframework.data.jpa.repository.config.EnableJpaRepositories;
+import org.springframework.jdbc.datasource.embedded.EmbeddedDatabase;
+import org.springframework.jdbc.datasource.embedded.EmbeddedDatabaseBuilder;
+import org.springframework.jdbc.datasource.embedded.EmbeddedDatabaseType;
+
+@EnableJpaRepositories("com.baeldung.dynamicvalidation.dao")
+@EntityScan("com.baeldung.dynamicvalidation.model")
+@Configuration
+public class PersistenceConfig {
+
+    @Bean
+    public DataSource dataSource() {
+        EmbeddedDatabaseBuilder builder = new EmbeddedDatabaseBuilder();
+        EmbeddedDatabase db = builder.setType(EmbeddedDatabaseType.H2).addScript("schema-expressions.sql").addScript("data-expressions.sql").build();
+        return db;
+    }
+}

spring-boot/src/main/java/com/baeldung/dynamicvalidation/dao/ContactInfoExpressionRepository.java

@@ -0,0 +1,11 @@
+package com.baeldung.dynamicvalidation.dao;
+
+import java.util.Optional;
+
+import org.springframework.data.repository.Repository;
+
+import com.baeldung.dynamicvalidation.model.ContactInfoExpression;
+
+public interface ContactInfoExpressionRepository extends Repository<ContactInfoExpression, String> {
+    Optional<ContactInfoExpression> findById(String id);
+}

spring-boot/src/main/java/com/baeldung/dynamicvalidation/model/ContactInfoExpression.java

@@ -0,0 +1,40 @@
+package com.baeldung.dynamicvalidation.model;
+
+import javax.persistence.Column;
+import javax.persistence.Entity;
+import javax.persistence.Id;
+
+@Entity
+public class ContactInfoExpression {
+
+    @Id
+    @Column(name = "expression_type")
+    private String type;
+    private String pattern;
+
+    public ContactInfoExpression() {
+
+    }
+
+    public ContactInfoExpression(final String type, final String pattern) {
+        this.type = type;
+        this.pattern = pattern;
+    }
+
+    public String getType() {
+        return type;
+    }
+
+    public void setType(final String type) {
+        this.type = type;
+    }
+
+    public String getPattern() {
+        return pattern;
+    }
+
+    public void setPattern(final String pattern) {
+        this.pattern = pattern;
+    }
+
+}

spring-boot/src/main/java/com/baeldung/dynamicvalidation/model/Customer.java

@@ -0,0 +1,46 @@
+package com.baeldung.dynamicvalidation.model;
+
+import javax.persistence.Entity;
+import javax.persistence.GeneratedValue;
+import javax.persistence.GenerationType;
+import javax.persistence.Id;
+import javax.validation.constraints.NotNull;
+
+import com.baeldung.dynamicvalidation.ContactInfo;
+
+@Entity
+public class Customer {
+
+    @Id
+    @GeneratedValue(strategy = GenerationType.IDENTITY)
+    private long id;
+
+    @ContactInfo
+    @NotNull
+    private String contactInfo;
+
+    public Customer() {
+    }
+
+    public Customer(final long id, final String contactInfo) {
+        this.id = id;
+        this.contactInfo = contactInfo;
+    }
+
+    public String getContactInfo() {
+        return contactInfo;
+    }
+
+    public void setContactInfo(final String contactInfo) {
+        this.contactInfo = contactInfo;
+    }
+
+    public long getId() {
+        return id;
+    }
+
+    public void setId(final long id) {
+        this.id = id;
+    }
+
+}

spring-boot/src/main/java/com/baeldung/errorhandling/ErrorHandlingApplication.java

@@ -0,0 +1,15 @@
+package com.baeldung.errorhandling;
+
+import org.springframework.boot.SpringApplication;
+import org.springframework.boot.autoconfigure.SpringBootApplication;
+import org.springframework.context.annotation.ComponentScan;
+
+@SpringBootApplication
+@ComponentScan(basePackages = "com.baeldung.errorhandling")
+public class ErrorHandlingApplication {
+
+    public static void main(String [] args) {
+        System.setProperty("spring.profiles.active", "errorhandling");
+        SpringApplication.run(ErrorHandlingApplication.class, args);
+    }
+}

spring-boot/src/main/java/com/baeldung/errorhandling/controllers/IndexController.java

@@ -0,0 +1,26 @@
+package com.baeldung.errorhandling.controllers;
+
+import org.springframework.stereotype.Controller;
+import org.springframework.web.bind.annotation.GetMapping;
+import org.springframework.web.bind.annotation.PostMapping;
+
+@Controller
+public class IndexController {
+
+    @GetMapping(value = {"/", ""})
+    public String index() {
+        return "index";
+    }
+
+    @GetMapping(value = {"/server_error"})
+    public String triggerServerError() {
+        "ser".charAt(30);
+        return "index";
+    }
+
+    @PostMapping(value = {"/general_error"})
+    public String triggerGeneralError() {
+        return "index";
+    }
+
+}

spring-boot/src/main/java/com/baeldung/errorhandling/controllers/MyErrorController.java

@@ -0,0 +1,40 @@
+package com.baeldung.errorhandling.controllers;
+
+import org.springframework.boot.web.servlet.error.ErrorController;
+import org.springframework.http.HttpStatus;
+import org.springframework.stereotype.Controller;
+import org.springframework.web.bind.annotation.GetMapping;
+
+import javax.servlet.RequestDispatcher;
+import javax.servlet.http.HttpServletRequest;
+
+@Controller
+public class MyErrorController implements ErrorController {
+
+    public MyErrorController() {}
+
+    @GetMapping(value = "/error")
+    public String handleError(HttpServletRequest request) {
+        
+        Object status = request.getAttribute(RequestDispatcher.ERROR_STATUS_CODE);
+
+        if (status != null) {
+        
+            Integer statusCode = Integer.valueOf(status.toString());
+
+            if(statusCode == HttpStatus.NOT_FOUND.value()) {
+                return "error-404";
+            }
+            else if(statusCode == HttpStatus.INTERNAL_SERVER_ERROR.value()) {
+                return "error-500";
+            }
+        }
+        return "error";
+    }
+
+    @Override
+    public String getErrorPath() {
+        return "/error";
+    }
+
+}

spring-boot/src/main/java/com/baeldung/failureanalyzer/FailureAnalyzerApplication.java

@@ -0,0 +1,14 @@
+package com.baeldung.failureanalyzer;
+
+import javax.annotation.security.RolesAllowed;
+
+import org.springframework.boot.SpringApplication;
+import org.springframework.boot.autoconfigure.SpringBootApplication;
+
+@SpringBootApplication
+public class FailureAnalyzerApplication {
+    @RolesAllowed("*")
+    public static void main(String[] args) {
+        SpringApplication.run(FailureAnalyzerApplication.class, args);
+    }
+}

spring-boot/src/main/java/com/baeldung/failureanalyzer/MyBeanNotOfRequiredTypeFailureAnalyzer.java

@@ -0,0 +1,22 @@
+package com.baeldung.failureanalyzer;
+
+import org.springframework.beans.factory.BeanNotOfRequiredTypeException;
+import org.springframework.boot.diagnostics.AbstractFailureAnalyzer;
+import org.springframework.boot.diagnostics.FailureAnalysis;
+
+public class MyBeanNotOfRequiredTypeFailureAnalyzer extends AbstractFailureAnalyzer<BeanNotOfRequiredTypeException> {
+
+    @Override
+    protected FailureAnalysis analyze(Throwable rootFailure, BeanNotOfRequiredTypeException cause) {
+        return new FailureAnalysis(getDescription(cause), getAction(cause), cause);
+    }
+
+    private String getDescription(BeanNotOfRequiredTypeException ex) {
+        return String.format("The bean %s could not be injected as %s because it is of type %s", ex.getBeanName(), ex.getRequiredType().getName(), ex.getActualType().getName());
+    }
+
+    private String getAction(BeanNotOfRequiredTypeException ex) {
+        return String.format("Consider creating a bean with name %s of type %s", ex.getBeanName(), ex.getRequiredType().getName());
+    }
+
+}

spring-boot/src/main/java/com/baeldung/failureanalyzer/MyDAO.java

@@ -0,0 +1,5 @@
+package com.baeldung.failureanalyzer;
+
+public class MyDAO {
+
+}

spring-boot/src/main/java/com/baeldung/failureanalyzer/MySecondDAO.java

@@ -0,0 +1,8 @@
+package com.baeldung.failureanalyzer;
+
+import org.springframework.stereotype.Repository;
+
+@Repository("myDAO")
+public class MySecondDAO {
+
+}

spring-boot/src/main/java/com/baeldung/failureanalyzer/MyService.java

@@ -0,0 +1,13 @@
+package com.baeldung.failureanalyzer;
+
+import javax.annotation.Resource;
+
+import org.springframework.stereotype.Service;
+
+@Service
+public class MyService {
+
+    @Resource(name = "myDAO")
+    private MyDAO myDAO;
+
+}

spring-boot/src/main/java/com/baeldung/git/CommitIdApplication.java

@@ -0,0 +1,23 @@
+package com.baeldung.git;
+
+import org.springframework.boot.SpringApplication;
+import org.springframework.boot.autoconfigure.SpringBootApplication;
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.support.PropertySourcesPlaceholderConfigurer;
+import org.springframework.core.io.ClassPathResource;
+
+@SpringBootApplication(scanBasePackages = { "com.baeldung.git" })
+public class CommitIdApplication {
+    public static void main(String[] args) {
+        SpringApplication.run(CommitIdApplication.class, args);
+    }
+
+    @Bean
+    public static PropertySourcesPlaceholderConfigurer placeholderConfigurer() {
+        PropertySourcesPlaceholderConfigurer c = new PropertySourcesPlaceholderConfigurer();
+        c.setLocation(new ClassPathResource("git.properties"));
+        c.setIgnoreResourceNotFound(true);
+        c.setIgnoreUnresolvablePlaceholders(true);
+        return c;
+    }
+}

spring-boot/src/main/java/com/baeldung/git/CommitInfoController.java

@@ -0,0 +1,30 @@
+package com.baeldung.git;
+
+import org.springframework.beans.factory.annotation.Value;
+import org.springframework.web.bind.annotation.GetMapping;
+import org.springframework.web.bind.annotation.RestController;
+
+import java.util.HashMap;
+import java.util.Map;
+
+@RestController
+public class CommitInfoController {
+
+    @Value("${git.commit.message.short}")
+    private String commitMessage;
+
+    @Value("${git.branch}")
+    private String branch;
+
+    @Value("${git.commit.id}")
+    private String commitId;
+
+    @GetMapping("/commitId")
+    public Map<String, String> getCommitId() {
+        Map<String, String> result = new HashMap<>();
+        result.put("Commit message", commitMessage);
+        result.put("Commit branch", branch);
+        result.put("Commit id", commitId);
+        return result;
+    }
+}

spring-boot/src/main/java/com/baeldung/git/README.md

@@ -0,0 +1,2 @@
+### Relevant Articles:
+- [Injecting Git Information Into Spring](http://www.baeldung.com/spring-git-information)

spring-boot/src/main/java/com/baeldung/graphql/Author.java

@@ -0,0 +1,31 @@
+package com.baeldung.graphql;
+
+public class Author {
+    private String id;
+    private String name;
+    private String thumbnail;
+
+    public String getId() {
+        return id;
+    }
+
+    public void setId(String id) {
+        this.id = id;
+    }
+
+    public String getName() {
+        return name;
+    }
+
+    public void setName(String name) {
+        this.name = name;
+    }
+
+    public String getThumbnail() {
+        return thumbnail;
+    }
+
+    public void setThumbnail(String thumbnail) {
+        this.thumbnail = thumbnail;
+    }
+}

spring-boot/src/main/java/com/baeldung/graphql/AuthorDao.java

@@ -0,0 +1,16 @@
+package com.baeldung.graphql;
+
+import java.util.List;
+import java.util.Optional;
+
+public class AuthorDao {
+    private List<Author> authors;
+
+    public AuthorDao(List<Author> authors) {
+        this.authors = authors;
+    }
+
+    public Optional<Author> getAuthor(String id) {
+        return authors.stream().filter(author -> id.equals(author.getId())).findFirst();
+    }
+}

spring-boot/src/main/java/com/baeldung/graphql/AuthorResolver.java

@@ -0,0 +1,17 @@
+package com.baeldung.graphql;
+
+import java.util.List;
+
+import com.coxautodev.graphql.tools.GraphQLResolver;
+
+public class AuthorResolver implements GraphQLResolver<Author> {
+    private PostDao postDao;
+
+    public AuthorResolver(PostDao postDao) {
+        this.postDao = postDao;
+    }
+
+    public List<Post> getPosts(Author author) {
+        return postDao.getAuthorPosts(author.getId());
+    }
+}

spring-boot/src/main/java/com/baeldung/graphql/GraphqlConfiguration.java

@@ -0,0 +1,59 @@
+package com.baeldung.graphql;
+
+import java.util.ArrayList;
+import java.util.List;
+
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+
+@Configuration
+public class GraphqlConfiguration {
+    @Bean
+    public PostDao postDao() {
+        List<Post> posts = new ArrayList<>();
+        for (int postId = 0; postId < 10; ++postId) {
+            for (int authorId = 0; authorId < 10; ++authorId) {
+                Post post = new Post();
+                post.setId("Post" + authorId + postId);
+                post.setTitle("Post " + authorId + ":" + postId);
+                post.setText("Post " + postId + " + by author " + authorId);
+                post.setAuthorId("Author" + authorId);
+                posts.add(post);
+            }
+        }
+        return new PostDao(posts);
+    }
+
+    @Bean
+    public AuthorDao authorDao() {
+        List<Author> authors = new ArrayList<>();
+        for (int authorId = 0; authorId < 10; ++authorId) {
+            Author author = new Author();
+            author.setId("Author" + authorId);
+            author.setName("Author " + authorId);
+            author.setThumbnail("http://example.com/authors/" + authorId);
+            authors.add(author);
+        }
+        return new AuthorDao(authors);
+    }
+
+    @Bean
+    public PostResolver postResolver(AuthorDao authorDao) {
+        return new PostResolver(authorDao);
+    }
+
+    @Bean
+    public AuthorResolver authorResolver(PostDao postDao) {
+        return new AuthorResolver(postDao);
+    }
+
+    @Bean
+    public Query query(PostDao postDao) {
+        return new Query(postDao);
+    }
+
+    @Bean
+    public Mutation mutation(PostDao postDao) {
+        return new Mutation(postDao);
+    }
+}

spring-boot/src/main/java/com/baeldung/graphql/Mutation.java

@@ -0,0 +1,25 @@
+package com.baeldung.graphql;
+
+import java.util.UUID;
+
+import com.coxautodev.graphql.tools.GraphQLMutationResolver;
+
+public class Mutation implements GraphQLMutationResolver {
+    private PostDao postDao;
+
+    public Mutation(PostDao postDao) {
+        this.postDao = postDao;
+    }
+
+    public Post writePost(String title, String text, String category, String author) {
+        Post post = new Post();
+        post.setId(UUID.randomUUID().toString());
+        post.setTitle(title);
+        post.setText(text);
+        post.setCategory(category);
+        post.setAuthorId(author);
+        postDao.savePost(post);
+
+        return post;
+    }
+}

spring-boot/src/main/java/com/baeldung/graphql/Post.java

@@ -0,0 +1,49 @@
+package com.baeldung.graphql;
+
+public class Post {
+    private String id;
+    private String title;
+    private String text;
+    private String category;
+    private String authorId;
+
+    public String getId() {
+        return id;
+    }
+
+    public void setId(String id) {
+        this.id = id;
+    }
+
+    public String getTitle() {
+        return title;
+    }
+
+    public void setTitle(String title) {
+        this.title = title;
+    }
+
+    public String getText() {
+        return text;
+    }
+
+    public void setText(String text) {
+        this.text = text;
+    }
+
+    public String getCategory() {
+        return category;
+    }
+
+    public void setCategory(String category) {
+        this.category = category;
+    }
+
+    public String getAuthorId() {
+        return authorId;
+    }
+
+    public void setAuthorId(String authorId) {
+        this.authorId = authorId;
+    }
+}

spring-boot/src/main/java/com/baeldung/graphql/PostDao.java

@@ -0,0 +1,24 @@
+package com.baeldung.graphql;
+
+import java.util.List;
+import java.util.stream.Collectors;
+
+public class PostDao {
+    private List<Post> posts;
+
+    public PostDao(List<Post> posts) {
+        this.posts = posts;
+    }
+
+    public List<Post> getRecentPosts(int count, int offset) {
+        return posts.stream().skip(offset).limit(count).collect(Collectors.toList());
+    }
+
+    public List<Post> getAuthorPosts(String author) {
+        return posts.stream().filter(post -> author.equals(post.getAuthorId())).collect(Collectors.toList());
+    }
+
+    public void savePost(Post post) {
+        posts.add(0, post);
+    }
+}

spring-boot/src/main/java/com/baeldung/graphql/PostResolver.java

@@ -0,0 +1,17 @@
+package com.baeldung.graphql;
+
+import java.util.Optional;
+
+import com.coxautodev.graphql.tools.GraphQLResolver;
+
+public class PostResolver implements GraphQLResolver<Post> {
+    private AuthorDao authorDao;
+
+    public PostResolver(AuthorDao authorDao) {
+        this.authorDao = authorDao;
+    }
+
+    public Optional<Author> getAuthor(Post post) {
+        return authorDao.getAuthor(post.getAuthorId());
+    }
+}

spring-boot/src/main/java/com/baeldung/graphql/Query.java

@@ -0,0 +1,17 @@
+package com.baeldung.graphql;
+
+import java.util.List;
+
+import com.coxautodev.graphql.tools.GraphQLQueryResolver;
+
+public class Query implements GraphQLQueryResolver {
+    private PostDao postDao;
+
+    public Query(PostDao postDao) {
+        this.postDao = postDao;
+    }
+
+    public List<Post> getRecentPosts(int count, int offset) {
+        return postDao.getRecentPosts(count, offset);
+    }
+}

spring-boot/src/main/java/com/baeldung/internationalization/InternationalizationApp.java

@@ -0,0 +1,14 @@
+package com.baeldung.internationalization;
+
+import javax.annotation.security.RolesAllowed;
+
+import org.springframework.boot.SpringApplication;
+import org.springframework.boot.autoconfigure.SpringBootApplication;
+
+@SpringBootApplication
+public class InternationalizationApp {
+    @RolesAllowed("*")
+    public static void main(String[] args) {
+        SpringApplication.run(InternationalizationApp.class, args);
+    }
+}

spring-boot/src/main/java/com/baeldung/internationalization/config/MvcConfig.java

@@ -0,0 +1,36 @@
+package com.baeldung.internationalization.config;
+
+import java.util.Locale;
+
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.ComponentScan;
+import org.springframework.context.annotation.Configuration;
+import org.springframework.web.servlet.LocaleResolver;
+import org.springframework.web.servlet.config.annotation.InterceptorRegistry;
+import org.springframework.web.servlet.config.annotation.WebMvcConfigurer;
+import org.springframework.web.servlet.i18n.LocaleChangeInterceptor;
+import org.springframework.web.servlet.i18n.SessionLocaleResolver;
+
+@Configuration
+@ComponentScan(basePackages = "com.baeldung.internationalization.config")
+public class MvcConfig implements WebMvcConfigurer {
+
+    @Bean
+    public LocaleResolver localeResolver() {
+        SessionLocaleResolver slr = new SessionLocaleResolver();
+        slr.setDefaultLocale(Locale.US);
+        return slr;
+    }
+
+    @Bean
+    public LocaleChangeInterceptor localeChangeInterceptor() {
+        LocaleChangeInterceptor lci = new LocaleChangeInterceptor();
+        lci.setParamName("lang");
+        return lci;
+    }
+
+    @Override
+    public void addInterceptors(InterceptorRegistry registry) {
+        registry.addInterceptor(localeChangeInterceptor());
+    }
+}

spring-boot/src/main/java/com/baeldung/internationalization/config/PageController.java

@@ -0,0 +1,14 @@
+package com.baeldung.internationalization.config;
+
+import org.springframework.stereotype.Controller;
+import org.springframework.web.bind.annotation.GetMapping;
+
+@Controller
+public class PageController {
+
+    @GetMapping("/international")
+    public String getInternationalPage() {
+        return "international";
+    }
+
+}

spring-boot/src/main/java/com/baeldung/intro/App.java

@@ -0,0 +1,11 @@
+package com.baeldung.intro;
+
+import org.springframework.boot.SpringApplication;
+import org.springframework.boot.autoconfigure.SpringBootApplication;
+
+@SpringBootApplication
+public class App {
+    public static void main(String[] args) {
+        SpringApplication.run(App.class, args);
+    }
+}

spring-boot/src/main/java/com/baeldung/intro/controller/HomeController.java

@@ -0,0 +1,18 @@
+package com.baeldung.intro.controller;
+
+import org.springframework.web.bind.annotation.GetMapping;
+import org.springframework.web.bind.annotation.RestController;
+
+@RestController
+public class HomeController {
+
+    @GetMapping("/")
+    public String root() {
+        return "Index Page";
+    }
+
+    @GetMapping("/local")
+    public String local() {
+        return "/local";
+    }
+}

spring-boot/src/main/java/com/baeldung/jsondateformat/Contact.java

@@ -0,0 +1,70 @@
+package com.baeldung.jsondateformat;
+
+import com.fasterxml.jackson.annotation.JsonFormat;
+
+import java.time.LocalDate;
+import java.time.LocalDateTime;
+
+public class Contact {
+
+    private String name;
+    private String address;
+    private String phone;
+
+    @JsonFormat(pattern="yyyy-MM-dd")
+    private LocalDate birthday;
+
+    @JsonFormat(pattern="yyyy-MM-dd HH:mm:ss")
+    private LocalDateTime lastUpdate;
+
+    public String getName() {
+        return name;
+    }
+
+    public void setName(String name) {
+        this.name = name;
+    }
+
+    public String getAddress() {
+        return address;
+    }
+
+    public void setAddress(String address) {
+        this.address = address;
+    }
+
+    public String getPhone() {
+        return phone;
+    }
+
+    public void setPhone(String phone) {
+        this.phone = phone;
+    }
+
+    public LocalDate getBirthday() {
+        return birthday;
+    }
+
+    public void setBirthday(LocalDate birthday) {
+        this.birthday = birthday;
+    }
+
+    public LocalDateTime getLastUpdate() {
+        return lastUpdate;
+    }
+
+    public void setLastUpdate(LocalDateTime lastUpdate) {
+        this.lastUpdate = lastUpdate;
+    }
+
+    public Contact() {
+    }
+
+    public Contact(String name, String address, String phone, LocalDate birthday, LocalDateTime lastUpdate) {
+        this.name = name;
+        this.address = address;
+        this.phone = phone;
+        this.birthday = birthday;
+        this.lastUpdate = lastUpdate;
+    }
+}

spring-boot/src/main/java/com/baeldung/jsondateformat/ContactApp.java

@@ -0,0 +1,13 @@
+package com.baeldung.jsondateformat;
+
+import org.springframework.boot.SpringApplication;
+import org.springframework.boot.autoconfigure.SpringBootApplication;
+
+@SpringBootApplication
+public class ContactApp {
+
+    public static void main(String[] args) {
+        SpringApplication.run(ContactApp.class, args);
+    }
+
+}

spring-boot/src/main/java/com/baeldung/jsondateformat/ContactAppConfig.java

@@ -0,0 +1,33 @@
+package com.baeldung.jsondateformat;
+
+import com.fasterxml.jackson.datatype.jsr310.ser.LocalDateSerializer;
+import com.fasterxml.jackson.datatype.jsr310.ser.LocalDateTimeSerializer;
+import org.springframework.boot.autoconfigure.condition.ConditionalOnProperty;
+import org.springframework.boot.autoconfigure.jackson.Jackson2ObjectMapperBuilderCustomizer;
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+import org.springframework.http.converter.json.Jackson2ObjectMapperBuilder;
+
+import java.time.format.DateTimeFormatter;
+
+@Configuration
+public class ContactAppConfig {
+
+    private static final String dateFormat = "yyyy-MM-dd";
+
+    private static final String dateTimeFormat = "yyyy-MM-dd HH:mm:ss";
+
+    @Bean
+    @ConditionalOnProperty(value = "spring.jackson.date-format", matchIfMissing = true, havingValue = "none")
+    public Jackson2ObjectMapperBuilderCustomizer jsonCustomizer() {
+        return new Jackson2ObjectMapperBuilderCustomizer() {
+            @Override
+            public void customize(Jackson2ObjectMapperBuilder builder) {
+                builder.simpleDateFormat(dateTimeFormat);
+                builder.serializers(new LocalDateSerializer(DateTimeFormatter.ofPattern(dateFormat)));
+                builder.serializers(new LocalDateTimeSerializer(DateTimeFormatter.ofPattern(dateTimeFormat)));
+            }
+        };
+    }
+
+}

spring-boot/src/main/java/com/baeldung/jsondateformat/ContactController.java

@@ -0,0 +1,77 @@
+package com.baeldung.jsondateformat;
+
+import org.springframework.web.bind.annotation.GetMapping;
+import org.springframework.web.bind.annotation.RequestMapping;
+import org.springframework.web.bind.annotation.RestController;
+
+import java.time.LocalDate;
+import java.time.LocalDateTime;
+import java.util.ArrayList;
+import java.util.Date;
+import java.util.List;
+
+@RestController
+@RequestMapping(value = "/contacts")
+public class ContactController {
+
+    @GetMapping
+    public List<Contact> getContacts() {
+        List<Contact> contacts = new ArrayList<>();
+
+        Contact contact1 = new Contact("John Doe", "123 Sesame Street", "123-456-789", LocalDate.now(), LocalDateTime.now());
+        Contact contact2 = new Contact("John Doe 2", "124 Sesame Street", "123-456-789", LocalDate.now(), LocalDateTime.now());
+        Contact contact3 = new Contact("John Doe 3", "125 Sesame Street", "123-456-789", LocalDate.now(), LocalDateTime.now());
+
+        contacts.add(contact1);
+        contacts.add(contact2);
+        contacts.add(contact3);
+
+        return contacts;
+    }
+
+    @GetMapping("/javaUtilDate")
+    public List<ContactWithJavaUtilDate> getContactsWithJavaUtilDate() {
+        List<ContactWithJavaUtilDate> contacts = new ArrayList<>();
+
+        ContactWithJavaUtilDate contact1 = new ContactWithJavaUtilDate("John Doe", "123 Sesame Street", "123-456-789", new Date(), new Date());
+        ContactWithJavaUtilDate contact2 = new ContactWithJavaUtilDate("John Doe 2", "124 Sesame Street", "123-456-789", new Date(), new Date());
+        ContactWithJavaUtilDate contact3 = new ContactWithJavaUtilDate("John Doe 3", "125 Sesame Street", "123-456-789", new Date(), new Date());
+
+        contacts.add(contact1);
+        contacts.add(contact2);
+        contacts.add(contact3);
+
+        return contacts;
+    }
+
+    @GetMapping("/plain")
+    public List<PlainContact> getPlainContacts() {
+        List<PlainContact> contacts = new ArrayList<>();
+
+        PlainContact contact1 = new PlainContact("John Doe", "123 Sesame Street", "123-456-789", LocalDate.now(), LocalDateTime.now());
+        PlainContact contact2 = new PlainContact("John Doe 2", "124 Sesame Street", "123-456-789", LocalDate.now(), LocalDateTime.now());
+        PlainContact contact3 = new PlainContact("John Doe 3", "125 Sesame Street", "123-456-789", LocalDate.now(), LocalDateTime.now());
+
+        contacts.add(contact1);
+        contacts.add(contact2);
+        contacts.add(contact3);
+
+        return contacts;
+    }
+
+    @GetMapping("/plainWithJavaUtilDate")
+    public List<PlainContactWithJavaUtilDate> getPlainContactsWithJavaUtilDate() {
+        List<PlainContactWithJavaUtilDate> contacts = new ArrayList<>();
+
+        PlainContactWithJavaUtilDate contact1 = new PlainContactWithJavaUtilDate("John Doe", "123 Sesame Street", "123-456-789", new Date(), new Date());
+        PlainContactWithJavaUtilDate contact2 = new PlainContactWithJavaUtilDate("John Doe 2", "124 Sesame Street", "123-456-789", new Date(), new Date());
+        PlainContactWithJavaUtilDate contact3 = new PlainContactWithJavaUtilDate("John Doe 3", "125 Sesame Street", "123-456-789", new Date(), new Date());
+
+        contacts.add(contact1);
+        contacts.add(contact2);
+        contacts.add(contact3);
+
+        return contacts;
+    }
+
+}

spring-boot/src/main/java/com/baeldung/jsondateformat/ContactWithJavaUtilDate.java

@@ -0,0 +1,69 @@
+package com.baeldung.jsondateformat;
+
+import com.fasterxml.jackson.annotation.JsonFormat;
+
+import java.util.Date;
+
+public class ContactWithJavaUtilDate {
+
+    private String name;
+    private String address;
+    private String phone;
+
+    @JsonFormat(pattern="yyyy-MM-dd")
+    private Date birthday;
+
+    @JsonFormat(pattern="yyyy-MM-dd HH:mm:ss")
+    private Date lastUpdate;
+
+    public String getName() {
+        return name;
+    }
+
+    public void setName(String name) {
+        this.name = name;
+    }
+
+    public String getAddress() {
+        return address;
+    }
+
+    public void setAddress(String address) {
+        this.address = address;
+    }
+
+    public String getPhone() {
+        return phone;
+    }
+
+    public void setPhone(String phone) {
+        this.phone = phone;
+    }
+
+    public Date getBirthday() {
+        return birthday;
+    }
+
+    public void setBirthday(Date birthday) {
+        this.birthday = birthday;
+    }
+
+    public Date getLastUpdate() {
+        return lastUpdate;
+    }
+
+    public void setLastUpdate(Date lastUpdate) {
+        this.lastUpdate = lastUpdate;
+    }
+
+    public ContactWithJavaUtilDate() {
+    }
+
+    public ContactWithJavaUtilDate(String name, String address, String phone, Date birthday, Date lastUpdate) {
+        this.name = name;
+        this.address = address;
+        this.phone = phone;
+        this.birthday = birthday;
+        this.lastUpdate = lastUpdate;
+    }
+}

spring-boot/src/main/java/com/baeldung/jsondateformat/PlainContact.java

@@ -0,0 +1,66 @@
+package com.baeldung.jsondateformat;
+
+import java.time.LocalDate;
+import java.time.LocalDateTime;
+
+public class PlainContact {
+
+    private String name;
+    private String address;
+    private String phone;
+
+    private LocalDate birthday;
+
+    private LocalDateTime lastUpdate;
+
+    public String getName() {
+        return name;
+    }
+
+    public void setName(String name) {
+        this.name = name;
+    }
+
+    public String getAddress() {
+        return address;
+    }
+
+    public void setAddress(String address) {
+        this.address = address;
+    }
+
+    public String getPhone() {
+        return phone;
+    }
+
+    public void setPhone(String phone) {
+        this.phone = phone;
+    }
+
+    public LocalDate getBirthday() {
+        return birthday;
+    }
+
+    public void setBirthday(LocalDate birthday) {
+        this.birthday = birthday;
+    }
+
+    public LocalDateTime getLastUpdate() {
+        return lastUpdate;
+    }
+
+    public void setLastUpdate(LocalDateTime lastUpdate) {
+        this.lastUpdate = lastUpdate;
+    }
+
+    public PlainContact() {
+    }
+
+    public PlainContact(String name, String address, String phone, LocalDate birthday, LocalDateTime lastUpdate) {
+        this.name = name;
+        this.address = address;
+        this.phone = phone;
+        this.birthday = birthday;
+        this.lastUpdate = lastUpdate;
+    }
+}

spring-boot/src/main/java/com/baeldung/jsondateformat/PlainContactWithJavaUtilDate.java

@@ -0,0 +1,69 @@
+package com.baeldung.jsondateformat;
+
+import com.fasterxml.jackson.annotation.JsonFormat;
+
+import java.util.Date;
+
+public class PlainContactWithJavaUtilDate {
+
+    private String name;
+    private String address;
+    private String phone;
+
+    @JsonFormat(pattern="yyyy-MM-dd")
+    private Date birthday;
+
+    @JsonFormat(pattern="yyyy-MM-dd HH:mm:ss")
+    private Date lastUpdate;
+
+    public String getName() {
+        return name;
+    }
+
+    public void setName(String name) {
+        this.name = name;
+    }
+
+    public String getAddress() {
+        return address;
+    }
+
+    public void setAddress(String address) {
+        this.address = address;
+    }
+
+    public String getPhone() {
+        return phone;
+    }
+
+    public void setPhone(String phone) {
+        this.phone = phone;
+    }
+
+    public Date getBirthday() {
+        return birthday;
+    }
+
+    public void setBirthday(Date birthday) {
+        this.birthday = birthday;
+    }
+
+    public Date getLastUpdate() {
+        return lastUpdate;
+    }
+
+    public void setLastUpdate(Date lastUpdate) {
+        this.lastUpdate = lastUpdate;
+    }
+
+    public PlainContactWithJavaUtilDate() {
+    }
+
+    public PlainContactWithJavaUtilDate(String name, String address, String phone, Date birthday, Date lastUpdate) {
+        this.name = name;
+        this.address = address;
+        this.phone = phone;
+        this.birthday = birthday;
+        this.lastUpdate = lastUpdate;
+    }
+}

spring-boot/src/main/java/com/baeldung/kong/QueryController.java

@@ -0,0 +1,31 @@
+package com.baeldung.kong;
+
+import org.springframework.web.bind.annotation.GetMapping;
+import org.springframework.web.bind.annotation.PathVariable;
+import org.springframework.web.bind.annotation.RequestMapping;
+import org.springframework.web.bind.annotation.RestController;
+
+/**
+ * @author aiet
+ */
+@RestController
+@RequestMapping("/stock")
+public class QueryController {
+
+    private static int REQUEST_COUNTER = 0;
+
+    @GetMapping("/reqcount")
+    public int getReqCount() {
+        return REQUEST_COUNTER;
+    }
+
+    @GetMapping("/{code}")
+    public String getStockPrice(@PathVariable String code) {
+        REQUEST_COUNTER++;
+        if ("BTC".equalsIgnoreCase(code))
+            return "10000";
+        else
+            return "N/A";
+    }
+
+}

spring-boot/src/main/java/com/baeldung/kong/StockApp.java

@@ -0,0 +1,13 @@
+package com.baeldung.kong;
+
+import org.springframework.boot.SpringApplication;
+import org.springframework.boot.autoconfigure.SpringBootApplication;
+
+@SpringBootApplication
+public class StockApp {
+
+    public static void main(String[] args) {
+        SpringApplication.run(StockApp.class, args);
+    }
+
+}

spring-boot/src/main/java/com/baeldung/rss/ArticleFeedView.java

@@ -0,0 +1,54 @@
+package com.baeldung.rss;
+
+import com.rometools.rome.feed.rss.Channel;
+import com.rometools.rome.feed.rss.Description;
+import com.rometools.rome.feed.rss.Item;
+import org.springframework.stereotype.Service;
+import org.springframework.web.servlet.view.feed.AbstractRssFeedView;
+
+import javax.servlet.http.HttpServletRequest;
+import javax.servlet.http.HttpServletResponse;
+import java.util.ArrayList;
+import java.util.Date;
+import java.util.List;
+import java.util.Map;
+
+@Service("articleFeedView")
+public class ArticleFeedView extends AbstractRssFeedView {
+
+    protected Channel newFeed() {
+        Channel channel = new Channel("rss_2.0");
+        channel.setLink("http://localhost:8080/rss");
+        channel.setTitle("Article Feed");
+        channel.setDescription("Article Feed Description");
+        channel.setPubDate(new Date());
+        return channel;
+    }
+
+    @Override
+    protected List<Item> buildFeedItems(Map<String, Object> map, HttpServletRequest httpStRequest, HttpServletResponse httpStResponse) throws Exception {
+        List list = new ArrayList<Item>();
+
+        Item item1 = new Item();
+        item1.setLink("http://www.baeldung.com/netty-exception-handling");
+        item1.setTitle("Exceptions in Netty");
+        Description description1 = new Description();
+        description1.setValue("In this quick article, we’ll be looking at exception handling in Netty.");
+        item1.setDescription(description1);
+        item1.setPubDate(new Date());
+        item1.setAuthor("Carlos");
+
+        Item item2 = new Item();
+        item2.setLink("http://www.baeldung.com/cockroachdb-java");
+        item2.setTitle("Guide to CockroachDB in Java");
+        Description description2 = new Description();
+        description2.setValue("This tutorial is an introductory guide to using CockroachDB with Java.");
+        item2.setDescription(description2);
+        item2.setPubDate(new Date());
+        item2.setAuthor("Baeldung");
+
+        list.add(item1);
+        list.add(item2);
+        return list;
+    }
+}

spring-boot/src/main/java/com/baeldung/rss/ArticleRssController.java

@@ -0,0 +1,16 @@
+package com.baeldung.rss;
+
+import org.springframework.stereotype.Controller;
+import org.springframework.web.bind.annotation.GetMapping;
+import org.springframework.web.bind.annotation.RequestMapping;
+
+@Controller
+@RequestMapping(value = "/rss", produces = "application/*")
+public class ArticleRssController {
+
+    @GetMapping
+    public String articleFeed() {
+        return "articleFeedView";
+    }
+
+}

spring-boot/src/main/java/com/baeldung/rss/CustomContainer.java

@@ -0,0 +1,17 @@
+package com.baeldung.rss;
+
+import org.springframework.boot.web.server.WebServerFactoryCustomizer;
+import org.springframework.boot.web.servlet.server.ConfigurableServletWebServerFactory;
+import org.springframework.stereotype.Component;
+
+@Component
+public class CustomContainer implements WebServerFactoryCustomizer<ConfigurableServletWebServerFactory> {
+
+    @Override
+    public void customize(ConfigurableServletWebServerFactory factory) {
+        factory.setContextPath("");
+        factory.setPort(8080);
+
+    }
+
+}

spring-boot/src/main/java/com/baeldung/rss/RssApp.java

@@ -0,0 +1,18 @@
+package com.baeldung.rss;
+
+import javax.annotation.security.RolesAllowed;
+
+import org.springframework.boot.SpringApplication;
+import org.springframework.boot.autoconfigure.SpringBootApplication;
+import org.springframework.context.annotation.ComponentScan;
+
+@SpringBootApplication
+@ComponentScan(basePackages = "com.baeldung.rss")
+public class RssApp {
+
+    @RolesAllowed("*")
+    public static void main(String[] args) {
+        SpringApplication.run(RssApp.class, args);
+    }
+
+}

spring-boot/src/main/java/com/baeldung/servletinitializer/WarInitializerApplication.java

@@ -0,0 +1,36 @@
+package com.baeldung.servletinitializer;
+
+import java.time.LocalDateTime;
+
+import org.springframework.boot.SpringApplication;
+import org.springframework.boot.autoconfigure.SpringBootApplication;
+import org.springframework.boot.builder.SpringApplicationBuilder;
+import org.springframework.boot.web.servlet.support.SpringBootServletInitializer;
+import org.springframework.ui.Model;
+import org.springframework.web.bind.annotation.GetMapping;
+import org.springframework.web.bind.annotation.RestController;
+
+@SpringBootApplication
+public class WarInitializerApplication extends SpringBootServletInitializer {
+
+    @Override
+    protected SpringApplicationBuilder configure(SpringApplicationBuilder builder) {
+        return builder.sources(WarInitializerApplication.class);
+    }
+
+    public static void main(String[] args) {
+        SpringApplication sa = new SpringApplication(WarInitializerApplication.class);
+        sa.setLogStartupInfo(false);
+        sa.run(args);
+    }
+
+    @RestController
+    public static class WarInitializerController {
+
+        @GetMapping("/")
+        public String handler(Model model) {
+            model.addAttribute("date", LocalDateTime.now());
+            return "WarInitializerApplication is up and running!";
+        }
+    }
+}

spring-boot/src/main/java/com/baeldung/servlets/ApplicationMain.java

@@ -0,0 +1,19 @@
+package com.baeldung.servlets;
+
+import org.springframework.boot.SpringApplication;
+import org.springframework.boot.autoconfigure.SpringBootApplication;
+import org.springframework.boot.builder.SpringApplicationBuilder;
+import org.springframework.boot.web.servlet.support.SpringBootServletInitializer;
+
+@SpringBootApplication
+public class ApplicationMain extends SpringBootServletInitializer {
+
+    public static void main(String[] args) {
+        SpringApplication.run(ApplicationMain.class, args);
+    }
+
+    @Override
+    protected SpringApplicationBuilder configure(SpringApplicationBuilder application) {
+        return application.sources(ApplicationMain.class);
+    }
+}

spring-boot/src/main/java/com/baeldung/servlets/configuration/WebAppInitializer.java

@@ -0,0 +1,32 @@
+package com.baeldung.servlets.configuration;
+
+import org.springframework.web.WebApplicationInitializer;
+import org.springframework.web.context.support.AnnotationConfigWebApplicationContext;
+import org.springframework.web.context.support.XmlWebApplicationContext;
+import org.springframework.web.servlet.DispatcherServlet;
+import javax.servlet.ServletContext;
+import javax.servlet.ServletException;
+import javax.servlet.ServletRegistration;
+
+public class WebAppInitializer implements WebApplicationInitializer {
+
+    public void onStartup(ServletContext container) throws ServletException {
+
+        AnnotationConfigWebApplicationContext ctx = new AnnotationConfigWebApplicationContext();
+        ctx.register(WebMvcConfigure.class);
+        ctx.setServletContext(container);
+
+        ServletRegistration.Dynamic servletOne = container.addServlet("SpringProgrammaticDispatcherServlet", new DispatcherServlet(ctx));
+        servletOne.setLoadOnStartup(1);
+        servletOne.addMapping("/");
+
+        XmlWebApplicationContext xctx = new XmlWebApplicationContext();
+        xctx.setConfigLocation("/WEB-INF/context.xml");
+        xctx.setServletContext(container);
+
+        ServletRegistration.Dynamic servletTwo = container.addServlet("SpringProgrammaticXMLDispatcherServlet", new DispatcherServlet(xctx));
+        servletTwo.setLoadOnStartup(1);
+        servletTwo.addMapping("/");
+    }
+
+}

spring-boot/src/main/java/com/baeldung/servlets/configuration/WebMvcConfigure.java

@@ -0,0 +1,38 @@
+package com.baeldung.servlets.configuration;
+
+import org.springframework.boot.web.servlet.support.ErrorPageFilter;
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+import org.springframework.web.servlet.ViewResolver;
+import org.springframework.web.servlet.config.annotation.DefaultServletHandlerConfigurer;
+import org.springframework.web.servlet.config.annotation.ResourceHandlerRegistry;
+import org.springframework.web.servlet.config.annotation.WebMvcConfigurer;
+import org.springframework.web.servlet.resource.PathResourceResolver;
+import org.springframework.web.servlet.view.InternalResourceViewResolver;
+
+@Configuration
+public class WebMvcConfigure implements WebMvcConfigurer {
+
+    @Bean
+    public ViewResolver getViewResolver() {
+        InternalResourceViewResolver resolver = new InternalResourceViewResolver();
+        resolver.setPrefix("/WEB-INF/");
+        resolver.setSuffix(".jsp");
+        return resolver;
+    }
+
+    @Override
+    public void configureDefaultServletHandling(DefaultServletHandlerConfigurer configurer) {
+        configurer.enable();
+    }
+
+    @Override
+    public void addResourceHandlers(ResourceHandlerRegistry registry) {
+        registry.addResourceHandler("/resources/**").addResourceLocations("/resources/").setCachePeriod(3600).resourceChain(true).addResolver(new PathResourceResolver());
+    }
+
+    @Bean
+    public ErrorPageFilter errorPageFilter() {
+        return new ErrorPageFilter();
+    }
+}

spring-boot/src/main/java/com/baeldung/servlets/props/Constants.java

@@ -0,0 +1,20 @@
+package com.baeldung.servlets.props;
+
+import org.springframework.beans.factory.annotation.Autowired;
+
+import java.util.Properties;
+
+public final class Constants {
+
+    @Autowired
+    PropertySourcesLoader psl;
+
+    public static final String breakLine = System.getProperty("line.separator");
+    private static final PropertyLoader pl = new PropertyLoader();
+    private static final Properties mainProps = pl.getProperties("custom.properties");
+    public static final String DISPATCHER_SERVLET_NAME = mainProps.getProperty("dispatcher.servlet.name");
+    public static final String DISPATCHER_SERVLET_MAPPING = mainProps.getProperty("dispatcher.servlet.mapping");
+    private final String EXAMPLE_SERVLET_NAME = psl.getProperty("example.servlet.name");
+    private final String EXAMPLE_SERVLET_MAPPING = psl.getProperty("example.servlet.mapping");
+
+}

spring-boot/src/main/java/com/baeldung/servlets/props/PropertyLoader.java

@@ -0,0 +1,27 @@
+package com.baeldung.servlets.props;
+
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import java.io.IOException;
+import java.io.InputStream;
+import java.util.Properties;
+
+public class PropertyLoader {
+    private static final Logger log = LoggerFactory.getLogger(PropertyLoader.class);
+
+    public Properties getProperties(String file) {
+        Properties prop = new Properties();
+        InputStream input = null;
+        try {
+            input = getClass().getResourceAsStream(file);
+            prop.load(input);
+            if (input != null) {
+                input.close();
+            }
+        } catch (IOException ex) {
+            log.error("IOException: " + ex);
+        }
+        return prop;
+    }
+}

spring-boot/src/main/java/com/baeldung/servlets/props/PropertySourcesLoader.java

@@ -0,0 +1,24 @@
+package com.baeldung.servlets.props;
+
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.context.annotation.ComponentScan;
+import org.springframework.context.annotation.Configuration;
+import org.springframework.context.annotation.PropertySource;
+import org.springframework.core.env.ConfigurableEnvironment;
+
+@Configuration
+@ComponentScan(basePackages = { "com.baeldung.servlets.*" })
+@PropertySource("classpath:custom.properties")
+public class PropertySourcesLoader {
+
+    private static final Logger log = LoggerFactory.getLogger(PropertySourcesLoader.class);
+
+    @Autowired
+    ConfigurableEnvironment env;
+
+    public String getProperty(String key) {
+        return env.getProperty(key);
+    }
+}

spring-boot/src/main/java/com/baeldung/servlets/servlets/GenericCustomServlet.java

@@ -0,0 +1,18 @@
+package com.baeldung.servlets.servlets;
+
+import javax.servlet.ServletException;
+import javax.servlet.http.HttpServlet;
+import javax.servlet.http.HttpServletRequest;
+import javax.servlet.http.HttpServletResponse;
+import java.io.IOException;
+import java.io.PrintWriter;
+
+public class GenericCustomServlet extends HttpServlet {
+
+    @Override
+    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
+        response.setContentType("text/html");
+        PrintWriter out = response.getWriter();
+        out.println("<p>Hello World</p>");
+    }
+}

spring-boot/src/main/java/com/baeldung/servlets/servlets/javaee/AnnotationServlet.java

@@ -0,0 +1,18 @@
+package com.baeldung.servlets.servlets.javaee;
+
+import javax.servlet.ServletException;
+import javax.servlet.annotation.WebServlet;
+import javax.servlet.http.HttpServlet;
+import javax.servlet.http.HttpServletRequest;
+import javax.servlet.http.HttpServletResponse;
+import java.io.IOException;
+
+@WebServlet(name = "AnnotationServlet", description = "Example Servlet Using Annotations", urlPatterns = { "/annotationservlet" })
+public class AnnotationServlet extends HttpServlet {
+    private static final long serialVersionUID = 1L;
+
+    @Override
+    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
+        request.getRequestDispatcher("/annotationservlet.jsp").forward(request, response);
+    }
+}

spring-boot/src/main/java/com/baeldung/servlets/servlets/javaee/EEWebXmlServlet.java

@@ -0,0 +1,20 @@
+package com.baeldung.servlets.servlets.javaee;
+
+import javax.servlet.ServletException;
+import javax.servlet.http.HttpServlet;
+import javax.servlet.http.HttpServletRequest;
+import javax.servlet.http.HttpServletResponse;
+import java.io.IOException;
+import java.io.PrintWriter;
+
+public class EEWebXmlServlet extends HttpServlet {
+
+    private static final long serialVersionUID = 1L;
+
+    @Override
+    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
+        response.setContentType("text/html");
+        PrintWriter out = response.getWriter();
+        out.println("<p>Hello World</p>");
+    }
+}

spring-boot/src/main/java/com/baeldung/servlets/servlets/springboot/SpringRegistrationBeanServlet.java

@@ -0,0 +1,17 @@
+package com.baeldung.servlets.servlets.springboot;
+
+import com.baeldung.servlets.servlets.GenericCustomServlet;
+import org.springframework.boot.web.servlet.ServletRegistrationBean;
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+
+@Configuration
+public class SpringRegistrationBeanServlet {
+
+    @Bean
+    public ServletRegistrationBean<GenericCustomServlet> genericCustomServlet() {
+        ServletRegistrationBean<GenericCustomServlet> bean = new ServletRegistrationBean<>(new GenericCustomServlet(), "/springregistrationbeanservlet/*");
+        bean.setLoadOnStartup(1);
+        return bean;
+    }
+}

spring-boot/src/main/java/com/baeldung/servlets/servlets/springboot/embedded/EmbeddedTomcatExample.java

@@ -0,0 +1,16 @@
+package com.baeldung.servlets.servlets.springboot.embedded;
+
+import org.springframework.boot.web.embedded.tomcat.TomcatServletWebServerFactory;
+import org.springframework.boot.web.servlet.server.ConfigurableServletWebServerFactory;
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+
+@Configuration
+public class EmbeddedTomcatExample {
+
+    @Bean
+    public ConfigurableServletWebServerFactory servletContainer() {
+        TomcatServletWebServerFactory tomcat = new TomcatServletWebServerFactory();
+        return tomcat;
+    }
+}

spring-boot/src/main/java/com/baeldung/shutdownhooks/ShutdownHookApplication.java

@@ -0,0 +1,14 @@
+package com.baeldung.shutdownhooks;
+
+import org.springframework.boot.SpringApplication;
+import org.springframework.boot.autoconfigure.EnableAutoConfiguration;
+import org.springframework.boot.autoconfigure.SpringBootApplication;
+
+@SpringBootApplication
+@EnableAutoConfiguration
+public class ShutdownHookApplication {
+
+    public static void main(String args[]) {
+        SpringApplication.run(ShutdownHookApplication.class, args);
+    }
+}

spring-boot/src/main/java/com/baeldung/shutdownhooks/beans/Bean1.java

@@ -0,0 +1,14 @@
+package com.baeldung.shutdownhooks.beans;
+
+import javax.annotation.PreDestroy;
+
+import org.springframework.stereotype.Component;
+
+@Component
+public class Bean1 {
+
+    @PreDestroy
+    public void destroy() {
+        System.out.println("Shutdown triggered using @PreDestroy.");
+    }
+}

spring-boot/src/main/java/com/baeldung/shutdownhooks/beans/Bean2.java

@@ -0,0 +1,14 @@
+package com.baeldung.shutdownhooks.beans;
+
+import org.springframework.beans.factory.DisposableBean;
+import org.springframework.stereotype.Component;
+
+@Component
+public class Bean2 implements DisposableBean {
+
+    @Override
+    public void destroy() throws Exception {
+        System.out.println("Shutdown triggered using DisposableBean.");
+    }
+
+}

spring-boot/src/main/java/com/baeldung/shutdownhooks/beans/Bean3.java

@@ -0,0 +1,8 @@
+package com.baeldung.shutdownhooks.beans;
+
+public class Bean3 {
+
+    public void destroy() {
+        System.out.println("Shutdown triggered using bean destroy method.");
+    }
+}

spring-boot/src/main/java/com/baeldung/shutdownhooks/config/ExampleServletContextListener.java

@@ -0,0 +1,18 @@
+package com.baeldung.shutdownhooks.config;
+
+import javax.servlet.ServletContextEvent;
+import javax.servlet.ServletContextListener;
+
+public class ExampleServletContextListener implements ServletContextListener {
+
+    @Override
+    public void contextDestroyed(ServletContextEvent event) {
+        System.out.println("Shutdown triggered using ServletContextListener.");
+    }
+
+    @Override
+    public void contextInitialized(ServletContextEvent event) {
+        // Triggers when context initializes
+    }
+
+}

spring-boot/src/main/java/com/baeldung/shutdownhooks/config/ShutdownHookConfiguration.java

@@ -0,0 +1,25 @@
+package com.baeldung.shutdownhooks.config;
+
+import javax.servlet.ServletContextListener;
+
+import org.springframework.boot.web.servlet.ServletListenerRegistrationBean;
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+
+import com.baeldung.shutdownhooks.beans.Bean3;
+
+@Configuration
+public class ShutdownHookConfiguration {
+
+    @Bean(destroyMethod = "destroy")
+    public Bean3 initializeBean3() {
+        return new Bean3();
+    }
+
+    @Bean
+    ServletListenerRegistrationBean<ServletContextListener> servletListener() {
+        ServletListenerRegistrationBean<ServletContextListener> srb = new ServletListenerRegistrationBean<>();
+        srb.setListener(new ExampleServletContextListener());
+        return srb;
+    }
+}

spring-boot/src/main/java/com/baeldung/toggle/Employee.java

@@ -0,0 +1,37 @@
+package com.baeldung.toggle;
+
+import javax.persistence.Entity;
+import javax.persistence.Id;
+
+@Entity
+public class Employee {
+
+    @Id
+    private long id;
+    private double salary;
+
+    public Employee() {
+    }
+
+    public Employee(long id, double salary) {
+        this.id = id;
+        this.salary = salary;
+    }
+
+    public long getId() {
+        return id;
+    }
+
+    public void setId(long id) {
+        this.id = id;
+    }
+
+    public double getSalary() {
+        return salary;
+    }
+
+    public void setSalary(double salary) {
+        this.salary = salary;
+    }
+
+}

spring-boot/src/main/java/com/baeldung/toggle/EmployeeRepository.java

@@ -0,0 +1,7 @@
+package com.baeldung.toggle;
+
+import org.springframework.data.repository.CrudRepository;
+
+public interface EmployeeRepository extends CrudRepository<Employee, Long> {
+
+}

spring-boot/src/main/java/com/baeldung/toggle/FeatureAssociation.java

@@ -0,0 +1,12 @@
+package com.baeldung.toggle;
+
+import java.lang.annotation.ElementType;
+import java.lang.annotation.Retention;
+import java.lang.annotation.RetentionPolicy;
+import java.lang.annotation.Target;
+
+@Retention(RetentionPolicy.RUNTIME)
+@Target({ ElementType.METHOD, ElementType.TYPE })
+public @interface FeatureAssociation {
+    MyFeatures value();
+}

spring-boot/src/main/java/com/baeldung/toggle/FeaturesAspect.java

@@ -0,0 +1,26 @@
+package com.baeldung.toggle;
+
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
+import org.aspectj.lang.ProceedingJoinPoint;
+import org.aspectj.lang.annotation.Around;
+import org.aspectj.lang.annotation.Aspect;
+import org.springframework.stereotype.Component;
+
+@Aspect
+@Component
+public class FeaturesAspect {
+
+    private static final Logger LOG = LogManager.getLogger(FeaturesAspect.class);
+
+    @Around(value = "@within(featureAssociation) || @annotation(featureAssociation)")
+    public Object checkAspect(ProceedingJoinPoint joinPoint, FeatureAssociation featureAssociation) throws Throwable {
+        if (featureAssociation.value().isActive()) {
+            return joinPoint.proceed();
+        } else {
+            LOG.info("Feature " + featureAssociation.value().name() + " is not enabled!");
+            return null;
+        }
+    }
+
+}

spring-boot/src/main/java/com/baeldung/toggle/MyFeatures.java

@@ -0,0 +1,23 @@
+package com.baeldung.toggle;
+
+import org.togglz.core.Feature;
+import org.togglz.core.activation.SystemPropertyActivationStrategy;
+import org.togglz.core.annotation.ActivationParameter;
+import org.togglz.core.annotation.DefaultActivationStrategy;
+import org.togglz.core.annotation.EnabledByDefault;
+import org.togglz.core.annotation.Label;
+import org.togglz.core.context.FeatureContext;
+
+public enum MyFeatures implements Feature {
+
+    @Label("Employee Management Feature")
+    @EnabledByDefault
+    @DefaultActivationStrategy(id = SystemPropertyActivationStrategy.ID, parameters = { @ActivationParameter(name = SystemPropertyActivationStrategy.PARAM_PROPERTY_NAME, value = "employee.feature"),
+            @ActivationParameter(name = SystemPropertyActivationStrategy.PARAM_PROPERTY_VALUE, value = "true") })
+    EMPLOYEE_MANAGEMENT_FEATURE;
+
+    public boolean isActive() {
+        return FeatureContext.getFeatureManager().isActive(this);
+    }
+
+}

spring-boot/src/main/java/com/baeldung/toggle/SalaryController.java

@@ -0,0 +1,20 @@
+package com.baeldung.toggle;
+
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.stereotype.Controller;
+import org.springframework.web.bind.annotation.PostMapping;
+import org.springframework.web.bind.annotation.RequestParam;
+import org.springframework.web.bind.annotation.ResponseBody;
+
+@Controller
+public class SalaryController {
+
+    @Autowired
+    SalaryService salaryService;
+
+    @PostMapping(value = "/increaseSalary")
+    @ResponseBody
+    public void increaseSalary(@RequestParam long id) {
+        salaryService.increaseSalary(id);
+    }
+}

spring-boot/src/main/java/com/baeldung/toggle/SalaryService.java

@@ -0,0 +1,19 @@
+package com.baeldung.toggle;
+
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.stereotype.Service;
+
+@Service
+public class SalaryService {
+
+    @Autowired
+    EmployeeRepository employeeRepository;
+
+    @FeatureAssociation(value = MyFeatures.EMPLOYEE_MANAGEMENT_FEATURE)
+    public void increaseSalary(long id) {
+        Employee employee = employeeRepository.findById(id).orElse(null);
+        employee.setSalary(employee.getSalary() + employee.getSalary() * 0.1);
+        employeeRepository.save(employee);
+    }
+
+}

spring-boot/src/main/java/com/baeldung/toggle/ToggleApplication.java

@@ -0,0 +1,14 @@
+package com.baeldung.toggle;
+
+import javax.annotation.security.RolesAllowed;
+
+import org.springframework.boot.SpringApplication;
+import org.springframework.boot.autoconfigure.SpringBootApplication;
+
+@SpringBootApplication
+public class ToggleApplication {
+    @RolesAllowed("*")
+    public static void main(String[] args) {
+        SpringApplication.run(ToggleApplication.class, args);
+    }
+}

spring-boot/src/main/java/com/baeldung/toggle/ToggleConfiguration.java

@@ -0,0 +1,20 @@
+package com.baeldung.toggle;
+
+import org.springframework.boot.autoconfigure.domain.EntityScan;
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+import org.springframework.data.jpa.repository.config.EnableJpaRepositories;
+import org.togglz.core.manager.EnumBasedFeatureProvider;
+import org.togglz.core.spi.FeatureProvider;
+
+@Configuration
+@EnableJpaRepositories("com.baeldung.toggle")
+@EntityScan("com.baeldung.toggle")
+public class ToggleConfiguration {
+
+    @Bean
+    public FeatureProvider featureProvider() {
+        return new EnumBasedFeatureProvider(MyFeatures.class);
+    }
+
+}

spring-boot/src/main/java/com/baeldung/utils/UtilsApplication.java

@@ -0,0 +1,18 @@
+package com.baeldung.utils;
+
+import javax.annotation.security.RolesAllowed;
+
+import org.springframework.boot.SpringApplication;
+import org.springframework.boot.autoconfigure.SpringBootApplication;
+import org.springframework.context.annotation.ComponentScan;
+
+@SpringBootApplication
+@ComponentScan(basePackages = "com.baeldung.utils")
+public class UtilsApplication {
+
+    @RolesAllowed("*")
+    public static void main(String[] args) {
+        SpringApplication.run(UtilsApplication.class, args);
+    }
+
+}

spring-boot/src/main/java/com/baeldung/utils/controller/UtilsController.java

@@ -0,0 +1,48 @@
+package com.baeldung.utils.controller;
+
+import javax.servlet.http.HttpServletRequest;
+
+import org.springframework.stereotype.Controller;
+import org.springframework.ui.Model;
+import org.springframework.web.bind.ServletRequestUtils;
+import org.springframework.web.bind.annotation.GetMapping;
+import org.springframework.web.bind.annotation.PostMapping;
+import org.springframework.web.util.WebUtils;
+
+@Controller
+public class UtilsController {
+
+    @GetMapping("/utils")
+    public String webUtils(Model model) {
+        return "utils";
+    }
+
+    @PostMapping("/setParam")
+    public String post(HttpServletRequest request, Model model) {
+        String param = ServletRequestUtils.getStringParameter(request, "param", "DEFAULT");
+
+        // Long param = ServletRequestUtils.getLongParameter(request, "param",1L);
+        // boolean param = ServletRequestUtils.getBooleanParameter(request, "param", true);
+        // double param = ServletRequestUtils.getDoubleParameter(request, "param", 1000);
+        // float param = ServletRequestUtils.getFloatParameter(request, "param", (float) 1.00);
+        // int param = ServletRequestUtils.getIntParameter(request, "param", 100);
+
+        // try {
+        // ServletRequestUtils.getRequiredStringParameter(request, "param");
+        // } catch (ServletRequestBindingException e) {
+        // e.printStackTrace();
+        // }
+
+        WebUtils.setSessionAttribute(request, "parameter", param);
+        model.addAttribute("parameter", "You set: " + (String) WebUtils.getSessionAttribute(request, "parameter"));
+        return "utils";
+    }
+
+    @GetMapping("/other")
+    public String other(HttpServletRequest request, Model model) {
+        String param = (String) WebUtils.getSessionAttribute(request, "parameter");
+        model.addAttribute("parameter", param);
+        return "other";
+    }
+
+}

spring-boot/src/main/java/org/baeldung/boot/Application.java

@@ -0,0 +1,14 @@
+package org.baeldung.boot;
+
+import org.springframework.boot.SpringApplication;
+import org.springframework.boot.autoconfigure.SpringBootApplication;
+import org.springframework.context.ApplicationContext;
+
+@SpringBootApplication
+public class Application {
+    private static ApplicationContext applicationContext;
+
+    public static void main(String[] args) {
+        applicationContext = SpringApplication.run(Application.class, args);
+    }
+}

spring-boot/src/main/java/org/baeldung/boot/config/H2JpaConfig.java

@@ -0,0 +1,67 @@
+package org.baeldung.boot.config;
+
+import java.util.Properties;
+
+import javax.persistence.EntityManagerFactory;
+import javax.sql.DataSource;
+
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+import org.springframework.context.annotation.PropertySource;
+import org.springframework.core.env.Environment;
+import org.springframework.data.jpa.repository.config.EnableJpaRepositories;
+import org.springframework.jdbc.datasource.DriverManagerDataSource;
+import org.springframework.orm.jpa.JpaTransactionManager;
+import org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean;
+import org.springframework.orm.jpa.vendor.HibernateJpaVendorAdapter;
+import org.springframework.transaction.annotation.EnableTransactionManagement;
+
+@Configuration
+@EnableJpaRepositories(basePackages = { "org.baeldung.boot.repository", "org.baeldung.boot.boottest", "org.baeldung.repository" })
+@PropertySource("classpath:persistence-generic-entity.properties")
+@EnableTransactionManagement
+public class H2JpaConfig {
+
+    @Autowired
+    private Environment env;
+
+    @Bean
+    public DataSource dataSource() {
+        final DriverManagerDataSource dataSource = new DriverManagerDataSource();
+        dataSource.setDriverClassName(env.getProperty("jdbc.driverClassName"));
+        dataSource.setUrl(env.getProperty("jdbc.url"));
+        dataSource.setUsername(env.getProperty("jdbc.user"));
+        dataSource.setPassword(env.getProperty("jdbc.pass"));
+
+        return dataSource;
+    }
+
+    @Bean
+    public LocalContainerEntityManagerFactoryBean entityManagerFactory() {
+        final LocalContainerEntityManagerFactoryBean em = new LocalContainerEntityManagerFactoryBean();
+        em.setDataSource(dataSource());
+        em.setPackagesToScan(new String[] { "org.baeldung.boot.domain", "org.baeldung.boot.model", "org.baeldung.boot.boottest", "org.baeldung.model" });
+        em.setJpaVendorAdapter(new HibernateJpaVendorAdapter());
+        em.setJpaProperties(additionalProperties());
+        return em;
+    }
+
+    @Bean
+    JpaTransactionManager transactionManager(final EntityManagerFactory entityManagerFactory) {
+        final JpaTransactionManager transactionManager = new JpaTransactionManager();
+        transactionManager.setEntityManagerFactory(entityManagerFactory);
+        return transactionManager;
+    }
+
+    final Properties additionalProperties() {
+        final Properties hibernateProperties = new Properties();
+
+        hibernateProperties.setProperty("hibernate.hbm2ddl.auto", env.getProperty("hibernate.hbm2ddl.auto"));
+        hibernateProperties.setProperty("hibernate.dialect", env.getProperty("hibernate.dialect"));
+        hibernateProperties.setProperty("hibernate.show_sql", env.getProperty("hibernate.show_sql"));
+
+        return hibernateProperties;
+    }
+
+}

spring-boot/src/main/java/org/baeldung/boot/config/WebConfig.java

@@ -0,0 +1,20 @@
+package org.baeldung.boot.config;
+
+import org.baeldung.boot.converter.StringToEmployeeConverter;
+import org.baeldung.boot.converter.StringToEnumConverterFactory;
+import org.baeldung.boot.converter.GenericBigDecimalConverter;
+import org.springframework.context.annotation.Configuration;
+import org.springframework.format.FormatterRegistry;
+import org.springframework.web.servlet.config.annotation.WebMvcConfigurer;
+
+@Configuration
+public class WebConfig implements WebMvcConfigurer {
+	 
+    @Override
+    public void addFormatters(FormatterRegistry registry) {
+        registry.addConverter(new StringToEmployeeConverter());
+        registry.addConverterFactory(new StringToEnumConverterFactory());
+        registry.addConverter(new GenericBigDecimalConverter());
+    }
+}
+