adding new module

spring-5-reactive/src/main/java/com/baeldung/Spring5Application.java

@@ -0,0 +1,15 @@
+package com.baeldung;
+
+import org.springframework.boot.SpringApplication;
+import org.springframework.boot.autoconfigure.SpringBootApplication;
+import org.springframework.context.annotation.ComponentScan;
+
+@SpringBootApplication
+@ComponentScan(basePackages = { "com.baeldung.web" })
+public class Spring5Application {
+
+    public static void main(String[] args) {
+        SpringApplication.run(Spring5Application.class, args);
+    }
+
+}

spring-5-reactive/src/main/java/com/baeldung/SpringSecurity5Application.java

@@ -0,0 +1,34 @@
+package com.baeldung;
+
+import org.springframework.context.ApplicationContext;
+import org.springframework.context.annotation.AnnotationConfigApplicationContext;
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.ComponentScan;
+import org.springframework.http.server.reactive.HttpHandler;
+import org.springframework.http.server.reactive.ReactorHttpHandlerAdapter;
+import org.springframework.web.reactive.config.EnableWebFlux;
+import org.springframework.web.server.adapter.WebHttpHandlerBuilder;
+import reactor.ipc.netty.NettyContext;
+import reactor.ipc.netty.http.server.HttpServer;
+
+@ComponentScan(basePackages = {"com.baeldung.security"})
+@EnableWebFlux
+public class SpringSecurity5Application {
+
+    public static void main(String[] args) {
+        try (AnnotationConfigApplicationContext context =
+                     new AnnotationConfigApplicationContext(SpringSecurity5Application.class)) {
+            context.getBean(NettyContext.class).onClose().block();
+        }
+    }
+
+    @Bean
+    public NettyContext nettyContext(ApplicationContext context) {
+        HttpHandler handler = WebHttpHandlerBuilder.applicationContext(context)
+                .build();
+        ReactorHttpHandlerAdapter adapter = new ReactorHttpHandlerAdapter(handler);
+        HttpServer httpServer = HttpServer.create("localhost", 8080);
+        return httpServer.newHandler(adapter).block();
+    }
+
+}

spring-5-reactive/src/main/java/com/baeldung/functional/Actor.java

@@ -0,0 +1,23 @@
+package com.baeldung.functional;
+
+class Actor {
+    private String firstname;
+    private String lastname;
+
+    public Actor() {
+    }
+
+    public Actor(String firstname, String lastname) {
+        this.firstname = firstname;
+        this.lastname = lastname;
+    }
+
+    public String getFirstname() {
+        return firstname;
+    }
+
+    public String getLastname() {
+        return lastname;
+    }
+
+}

spring-5-reactive/src/main/java/com/baeldung/functional/ExploreSpring5URLPatternUsingRouterFunctions.java

@@ -0,0 +1,61 @@
+package com.baeldung.functional;
+
+import static org.springframework.web.reactive.function.BodyInserters.fromObject;
+import static org.springframework.web.reactive.function.server.RequestPredicates.GET;
+import static org.springframework.web.reactive.function.server.RouterFunctions.route;
+import static org.springframework.web.reactive.function.server.RouterFunctions.toHttpHandler;
+import static org.springframework.web.reactive.function.server.ServerResponse.ok;
+
+import org.apache.catalina.Context;
+import org.apache.catalina.startup.Tomcat;
+import org.springframework.boot.web.embedded.tomcat.TomcatWebServer;
+import org.springframework.boot.web.server.WebServer;
+import org.springframework.core.io.ClassPathResource;
+import org.springframework.http.server.reactive.HttpHandler;
+import org.springframework.http.server.reactive.ServletHttpHandlerAdapter;
+import org.springframework.web.reactive.function.server.RouterFunction;
+import org.springframework.web.reactive.function.server.RouterFunctions;
+import org.springframework.web.reactive.function.server.ServerResponse;
+import org.springframework.web.server.WebHandler;
+import org.springframework.web.server.adapter.WebHttpHandlerBuilder;
+
+public class ExploreSpring5URLPatternUsingRouterFunctions {
+
+    private RouterFunction<ServerResponse> routingFunction() {
+
+        return route(GET("/p?ths"), serverRequest -> ok().body(fromObject("/p?ths"))).andRoute(GET("/test/{*id}"), serverRequest -> ok().body(fromObject(serverRequest.pathVariable("id"))))
+            .andRoute(GET("/*card"), serverRequest -> ok().body(fromObject("/*card path was accessed")))
+            .andRoute(GET("/{var1}_{var2}"), serverRequest -> ok().body(fromObject(serverRequest.pathVariable("var1") + " , " + serverRequest.pathVariable("var2"))))
+            .andRoute(GET("/{baeldung:[a-z]+}"), serverRequest -> ok().body(fromObject("/{baeldung:[a-z]+} was accessed and baeldung=" + serverRequest.pathVariable("baeldung"))))
+            .and(RouterFunctions.resources("/files/{*filepaths}", new ClassPathResource("files/")));
+    }
+
+    WebServer start() throws Exception {
+        WebHandler webHandler = (WebHandler) toHttpHandler(routingFunction());
+        HttpHandler httpHandler = WebHttpHandlerBuilder.webHandler(webHandler)
+            .filter(new IndexRewriteFilter())
+            .build();
+
+        Tomcat tomcat = new Tomcat();
+        tomcat.setHostname("localhost");
+        tomcat.setPort(9090);
+        Context rootContext = tomcat.addContext("", System.getProperty("java.io.tmpdir"));
+        ServletHttpHandlerAdapter servlet = new ServletHttpHandlerAdapter(httpHandler);
+        Tomcat.addServlet(rootContext, "httpHandlerServlet", servlet);
+        rootContext.addServletMappingDecoded("/", "httpHandlerServlet");
+
+        TomcatWebServer server = new TomcatWebServer(tomcat);
+        server.start();
+        return server;
+
+    }
+
+    public static void main(String[] args) {
+        try {
+            new FunctionalWebApplication().start();
+        } catch (Exception e) {
+            e.printStackTrace();
+        }
+    }
+
+}

spring-5-reactive/src/main/java/com/baeldung/functional/FormHandler.java

@@ -0,0 +1,41 @@
+package com.baeldung.functional;
+
+import org.springframework.core.io.buffer.DataBuffer;
+import org.springframework.util.MultiValueMap;
+import org.springframework.web.reactive.function.server.ServerRequest;
+import org.springframework.web.reactive.function.server.ServerResponse;
+import reactor.core.publisher.Mono;
+
+import java.util.List;
+import java.util.concurrent.atomic.AtomicLong;
+
+import static org.springframework.web.reactive.function.BodyExtractors.toDataBuffers;
+import static org.springframework.web.reactive.function.BodyExtractors.toFormData;
+import static org.springframework.web.reactive.function.BodyInserters.fromObject;
+import static org.springframework.web.reactive.function.server.ServerResponse.ok;
+
+public class FormHandler {
+
+    Mono<ServerResponse> handleLogin(ServerRequest request) {
+        return request.body(toFormData())
+            .map(MultiValueMap::toSingleValueMap)
+            .filter(formData -> "baeldung".equals(formData.get("user")))
+            .filter(formData -> "you_know_what_to_do".equals(formData.get("token")))
+            .flatMap(formData -> ok().body(Mono.just("welcome back!"), String.class))
+            .switchIfEmpty(ServerResponse.badRequest()
+                .build());
+    }
+
+    Mono<ServerResponse> handleUpload(ServerRequest request) {
+        return request.body(toDataBuffers())
+            .collectList()
+            .flatMap(dataBuffers -> ok().body(fromObject(extractData(dataBuffers).toString())));
+    }
+
+    private AtomicLong extractData(List<DataBuffer> dataBuffers) {
+        AtomicLong atomicLong = new AtomicLong(0);
+        dataBuffers.forEach(d -> atomicLong.addAndGet(d.asByteBuffer()
+            .array().length));
+        return atomicLong;
+    }
+}

spring-5-reactive/src/main/java/com/baeldung/functional/FunctionalSpringBootApplication.java

@@ -0,0 +1,87 @@
+package com.baeldung.functional;
+
+import static org.springframework.web.reactive.function.BodyInserters.fromObject;
+import static org.springframework.web.reactive.function.server.RequestPredicates.GET;
+import static org.springframework.web.reactive.function.server.RequestPredicates.POST;
+import static org.springframework.web.reactive.function.server.RequestPredicates.path;
+import static org.springframework.web.reactive.function.server.RouterFunctions.route;
+import static org.springframework.web.reactive.function.server.RouterFunctions.toHttpHandler;
+import static org.springframework.web.reactive.function.server.ServerResponse.ok;
+
+import java.util.Arrays;
+import java.util.List;
+import java.util.concurrent.CopyOnWriteArrayList;
+
+import org.springframework.boot.SpringApplication;
+import org.springframework.boot.autoconfigure.SpringBootApplication;
+import org.springframework.boot.web.servlet.ServletRegistrationBean;
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.ComponentScan;
+import org.springframework.context.annotation.Configuration;
+import org.springframework.context.annotation.Profile;
+import org.springframework.core.io.ClassPathResource;
+import org.springframework.http.server.reactive.HttpHandler;
+import org.springframework.security.config.annotation.web.builders.HttpSecurity;
+import org.springframework.security.config.annotation.web.configuration.EnableWebSecurity;
+import org.springframework.security.config.annotation.web.configuration.WebSecurityConfigurerAdapter;
+import org.springframework.web.reactive.function.server.RouterFunction;
+import org.springframework.web.reactive.function.server.RouterFunctions;
+import org.springframework.web.reactive.function.server.ServerResponse;
+import org.springframework.web.server.WebHandler;
+import org.springframework.web.server.adapter.WebHttpHandlerBuilder;
+
+import reactor.core.publisher.Flux;
+
+@SpringBootApplication
+@ComponentScan(basePackages = { "com.baeldung.functional" })
+public class FunctionalSpringBootApplication {
+
+    private static final Actor BRAD_PITT = new Actor("Brad", "Pitt");
+    private static final Actor TOM_HANKS = new Actor("Tom", "Hanks");
+    private static final List<Actor> actors = new CopyOnWriteArrayList<>(Arrays.asList(BRAD_PITT, TOM_HANKS));
+
+    private RouterFunction<ServerResponse> routingFunction() {
+        FormHandler formHandler = new FormHandler();
+
+        RouterFunction<ServerResponse> restfulRouter = route(GET("/"), serverRequest -> ok().body(Flux.fromIterable(actors), Actor.class)).andRoute(POST("/"), serverRequest -> serverRequest.bodyToMono(Actor.class)
+            .doOnNext(actors::add)
+            .then(ok().build()));
+
+        return route(GET("/test"), serverRequest -> ok().body(fromObject("helloworld"))).andRoute(POST("/login"), formHandler::handleLogin)
+            .andRoute(POST("/upload"), formHandler::handleUpload)
+            .and(RouterFunctions.resources("/files/**", new ClassPathResource("files/")))
+            .andNest(path("/actor"), restfulRouter)
+            .filter((request, next) -> {
+                System.out.println("Before handler invocation: " + request.path());
+                return next.handle(request);
+            });
+    }
+
+    @Bean
+    public ServletRegistrationBean servletRegistrationBean() throws Exception {
+        HttpHandler httpHandler = WebHttpHandlerBuilder.webHandler((WebHandler) toHttpHandler(routingFunction()))
+            .filter(new IndexRewriteFilter())
+            .build();
+        ServletRegistrationBean registrationBean = new ServletRegistrationBean<>(new RootServlet(httpHandler), "/");
+        registrationBean.setLoadOnStartup(1);
+        registrationBean.setAsyncSupported(true);
+        return registrationBean;
+    }
+
+    @Configuration
+    @EnableWebSecurity
+    @Profile("!https")
+    static class SecurityConfig extends WebSecurityConfigurerAdapter {
+        @Override
+        protected void configure(final HttpSecurity http) throws Exception {
+            http.authorizeRequests()
+                .anyRequest()
+                .permitAll();
+        }
+    }
+
+    public static void main(String[] args) {
+        SpringApplication.run(FunctionalSpringBootApplication.class, args);
+    }
+
+}

spring-5-reactive/src/main/java/com/baeldung/functional/FunctionalWebApplication.java

@@ -0,0 +1,80 @@
+package com.baeldung.functional;
+
+import static org.springframework.web.reactive.function.BodyInserters.fromObject;
+import static org.springframework.web.reactive.function.server.RequestPredicates.GET;
+import static org.springframework.web.reactive.function.server.RequestPredicates.POST;
+import static org.springframework.web.reactive.function.server.RequestPredicates.path;
+import static org.springframework.web.reactive.function.server.RouterFunctions.route;
+import static org.springframework.web.reactive.function.server.RouterFunctions.toHttpHandler;
+import static org.springframework.web.reactive.function.server.ServerResponse.ok;
+
+import java.util.Arrays;
+import java.util.List;
+import java.util.concurrent.CopyOnWriteArrayList;
+
+import org.apache.catalina.Context;
+import org.apache.catalina.startup.Tomcat;
+import org.springframework.boot.web.embedded.tomcat.TomcatWebServer;
+import org.springframework.boot.web.server.WebServer;
+import org.springframework.core.io.ClassPathResource;
+import org.springframework.http.server.reactive.HttpHandler;
+import org.springframework.http.server.reactive.ServletHttpHandlerAdapter;
+import org.springframework.web.reactive.function.server.RouterFunction;
+import org.springframework.web.reactive.function.server.RouterFunctions;
+import org.springframework.web.reactive.function.server.ServerResponse;
+import org.springframework.web.server.WebHandler;
+import org.springframework.web.server.adapter.WebHttpHandlerBuilder;
+
+import reactor.core.publisher.Flux;
+
+public class FunctionalWebApplication {
+
+    private static final Actor BRAD_PITT = new Actor("Brad", "Pitt");
+    private static final Actor TOM_HANKS = new Actor("Tom", "Hanks");
+    private static final List<Actor> actors = new CopyOnWriteArrayList<>(Arrays.asList(BRAD_PITT, TOM_HANKS));
+
+    private RouterFunction<ServerResponse> routingFunction() {
+        FormHandler formHandler = new FormHandler();
+
+        RouterFunction<ServerResponse> restfulRouter = route(GET("/"), serverRequest -> ok().body(Flux.fromIterable(actors), Actor.class)).andRoute(POST("/"), serverRequest -> serverRequest.bodyToMono(Actor.class)
+            .doOnNext(actors::add)
+            .then(ok().build()));
+
+        return route(GET("/test"), serverRequest -> ok().body(fromObject("helloworld"))).andRoute(POST("/login"), formHandler::handleLogin)
+            .andRoute(POST("/upload"), formHandler::handleUpload)
+            .and(RouterFunctions.resources("/files/**", new ClassPathResource("files/")))
+            .andNest(path("/actor"), restfulRouter)
+            .filter((request, next) -> {
+                System.out.println("Before handler invocation: " + request.path());
+                return next.handle(request);
+            });
+    }
+
+    WebServer start() throws Exception {
+        WebHandler webHandler = (WebHandler) toHttpHandler(routingFunction());
+        HttpHandler httpHandler = WebHttpHandlerBuilder.webHandler(webHandler)
+            .filter(new IndexRewriteFilter())
+            .build();
+
+        Tomcat tomcat = new Tomcat();
+        tomcat.setHostname("localhost");
+        tomcat.setPort(9090);
+        Context rootContext = tomcat.addContext("", System.getProperty("java.io.tmpdir"));
+        ServletHttpHandlerAdapter servlet = new ServletHttpHandlerAdapter(httpHandler);
+        Tomcat.addServlet(rootContext, "httpHandlerServlet", servlet);
+        rootContext.addServletMappingDecoded("/", "httpHandlerServlet");
+
+        TomcatWebServer server = new TomcatWebServer(tomcat);
+        server.start();
+        return server;
+
+    }
+
+    public static void main(String[] args) {
+        try {
+            new FunctionalWebApplication().start();
+        } catch (Exception e) {
+            e.printStackTrace();
+        }
+    }
+}

spring-5-reactive/src/main/java/com/baeldung/functional/IndexRewriteFilter.java

@@ -0,0 +1,27 @@
+package com.baeldung.functional;
+
+import org.springframework.http.server.reactive.ServerHttpRequest;
+import org.springframework.web.server.ServerWebExchange;
+import org.springframework.web.server.WebFilter;
+import org.springframework.web.server.WebFilterChain;
+import reactor.core.publisher.Mono;
+
+class IndexRewriteFilter implements WebFilter {
+
+    @Override
+    public Mono<Void> filter(ServerWebExchange serverWebExchange, WebFilterChain webFilterChain) {
+        ServerHttpRequest request = serverWebExchange.getRequest();
+        if (request.getURI()
+            .getPath()
+            .equals("/")) {
+            return webFilterChain.filter(serverWebExchange.mutate()
+                .request(builder -> builder.method(request.getMethod())
+                    .contextPath(request.getPath()
+                        .toString())
+                    .path("/test"))
+                .build());
+        }
+        return webFilterChain.filter(serverWebExchange);
+    }
+
+}

spring-5-reactive/src/main/java/com/baeldung/functional/MyService.java

@@ -0,0 +1,11 @@
+package com.baeldung.functional;
+
+import java.util.Random;
+
+public class MyService {
+
+    public int getRandomNumber() {
+        return (new Random().nextInt(10));
+    }
+
+}

spring-5-reactive/src/main/java/com/baeldung/functional/RootServlet.java

@@ -0,0 +1,82 @@
+package com.baeldung.functional;
+
+import static org.springframework.web.reactive.function.BodyExtractors.toDataBuffers;
+import static org.springframework.web.reactive.function.BodyExtractors.toFormData;
+import static org.springframework.web.reactive.function.BodyInserters.fromObject;
+import static org.springframework.web.reactive.function.server.RequestPredicates.GET;
+import static org.springframework.web.reactive.function.server.RequestPredicates.POST;
+import static org.springframework.web.reactive.function.server.RequestPredicates.path;
+import static org.springframework.web.reactive.function.server.RouterFunctions.route;
+import static org.springframework.web.reactive.function.server.RouterFunctions.toHttpHandler;
+import static org.springframework.web.reactive.function.server.ServerResponse.ok;
+
+import java.util.Arrays;
+import java.util.List;
+import java.util.concurrent.CopyOnWriteArrayList;
+import java.util.concurrent.atomic.AtomicLong;
+
+import org.springframework.core.io.ClassPathResource;
+import org.springframework.http.server.reactive.HttpHandler;
+import org.springframework.http.server.reactive.ServletHttpHandlerAdapter;
+import org.springframework.util.MultiValueMap;
+import org.springframework.web.reactive.function.server.RouterFunction;
+import org.springframework.web.reactive.function.server.RouterFunctions;
+import org.springframework.web.reactive.function.server.ServerResponse;
+import org.springframework.web.server.WebHandler;
+import org.springframework.web.server.adapter.WebHttpHandlerBuilder;
+
+import reactor.core.publisher.Flux;
+import reactor.core.publisher.Mono;
+
+public class RootServlet extends ServletHttpHandlerAdapter {
+
+    public RootServlet() {
+        this(WebHttpHandlerBuilder.webHandler((WebHandler) toHttpHandler(routingFunction()))
+            .filter(new IndexRewriteFilter())
+            .build());
+    }
+
+    RootServlet(HttpHandler httpHandler) {
+        super(httpHandler);
+    }
+
+    private static final Actor BRAD_PITT = new Actor("Brad", "Pitt");
+    private static final Actor TOM_HANKS = new Actor("Tom", "Hanks");
+    private static final List<Actor> actors = new CopyOnWriteArrayList<>(Arrays.asList(BRAD_PITT, TOM_HANKS));
+
+    private static RouterFunction<?> routingFunction() {
+
+        return route(GET("/test"), serverRequest -> ok().body(fromObject("helloworld"))).andRoute(POST("/login"), serverRequest -> serverRequest.body(toFormData())
+            .map(MultiValueMap::toSingleValueMap)
+            .map(formData -> {
+                System.out.println("form data: " + formData.toString());
+                if ("baeldung".equals(formData.get("user")) && "you_know_what_to_do".equals(formData.get("token"))) {
+                    return ok().body(Mono.just("welcome back!"), String.class)
+                        .block();
+                }
+                return ServerResponse.badRequest()
+                    .build()
+                    .block();
+            }))
+            .andRoute(POST("/upload"), serverRequest -> serverRequest.body(toDataBuffers())
+                .collectList()
+                .map(dataBuffers -> {
+                    AtomicLong atomicLong = new AtomicLong(0);
+                    dataBuffers.forEach(d -> atomicLong.addAndGet(d.asByteBuffer()
+                        .array().length));
+                    System.out.println("data length:" + atomicLong.get());
+                    return ok().body(fromObject(atomicLong.toString()))
+                        .block();
+                }))
+            .and(RouterFunctions.resources("/files/**", new ClassPathResource("files/")))
+            .andNest(path("/actor"), route(GET("/"), serverRequest -> ok().body(Flux.fromIterable(actors), Actor.class)).andRoute(POST("/"), serverRequest -> serverRequest.bodyToMono(Actor.class)
+                .doOnNext(actors::add)
+                .then(ok().build())))
+            .filter((request, next) -> {
+                System.out.println("Before handler invocation: " + request.path());
+                return next.handle(request);
+            });
+
+    }
+
+}

spring-5-reactive/src/main/java/com/baeldung/jsonb/Person.java

@@ -0,0 +1,127 @@
+package com.baeldung.jsonb;
+
+import java.math.BigDecimal;
+import java.time.LocalDate;
+
+import javax.json.bind.annotation.JsonbDateFormat;
+import javax.json.bind.annotation.JsonbNumberFormat;
+import javax.json.bind.annotation.JsonbProperty;
+import javax.json.bind.annotation.JsonbTransient;
+
+public class Person {
+
+    private int id;
+    @JsonbProperty("person-name")
+    private String name;
+    @JsonbProperty(nillable = true)
+    private String email;
+    @JsonbTransient
+    private int age;
+    @JsonbDateFormat("dd-MM-yyyy")
+    private LocalDate registeredDate;
+    private BigDecimal salary;
+
+    public Person() {
+    }
+
+    public Person(int id, String name, String email, int age, LocalDate registeredDate, BigDecimal salary) {
+        super();
+        this.id = id;
+        this.name = name;
+        this.email = email;
+        this.age = age;
+        this.registeredDate = registeredDate;
+        this.salary = salary;
+    }
+
+    public int getId() {
+        return id;
+    }
+
+    public void setId(int id) {
+        this.id = id;
+    }
+
+    public int getAge() {
+        return age;
+    }
+
+    public void setAge(int age) {
+        this.age = age;
+    }
+
+    public String getEmail() {
+        return email;
+    }
+
+    public void setEmail(String email) {
+        this.email = email;
+    }
+
+    public String getName() {
+        return name;
+    }
+
+    public void setName(String name) {
+        this.name = name;
+    }
+
+    @JsonbNumberFormat(locale = "en_US", value = "#0.0")
+    public BigDecimal getSalary() {
+        return salary;
+    }
+
+    public void setSalary(BigDecimal salary) {
+        this.salary = salary;
+    }
+
+    public LocalDate getRegisteredDate() {
+        return registeredDate;
+    }
+
+    public void setRegisteredDate(LocalDate registeredDate) {
+        this.registeredDate = registeredDate;
+    }
+
+    @Override
+    public String toString() {
+        StringBuilder builder = new StringBuilder();
+        builder.append("Person [id=");
+        builder.append(id);
+        builder.append(", name=");
+        builder.append(name);
+        builder.append(", email=");
+        builder.append(email);
+        builder.append(", age=");
+        builder.append(age);
+        builder.append(", registeredDate=");
+        builder.append(registeredDate);
+        builder.append(", salary=");
+        builder.append(salary);
+        builder.append("]");
+        return builder.toString();
+    }
+
+    @Override
+    public int hashCode() {
+        final int prime = 31;
+        int result = 1;
+        result = prime * result + id;
+        return result;
+    }
+
+    @Override
+    public boolean equals(Object obj) {
+        if (this == obj)
+            return true;
+        if (obj == null)
+            return false;
+        if (getClass() != obj.getClass())
+            return false;
+        Person other = (Person) obj;
+        if (id != other.id)
+            return false;
+        return true;
+    }
+
+}

spring-5-reactive/src/main/java/com/baeldung/jsonb/PersonController.java

@@ -0,0 +1,58 @@
+package com.baeldung.jsonb;
+
+import java.math.BigDecimal;
+import java.time.LocalDate;
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.List;
+
+import javax.annotation.PostConstruct;
+
+import org.springframework.http.HttpStatus;
+import org.springframework.web.bind.annotation.GetMapping;
+import org.springframework.web.bind.annotation.PathVariable;
+import org.springframework.web.bind.annotation.PostMapping;
+import org.springframework.web.bind.annotation.RequestBody;
+import org.springframework.web.bind.annotation.ResponseBody;
+import org.springframework.web.bind.annotation.ResponseStatus;
+import org.springframework.web.bind.annotation.RestController;
+
+@RestController("/person")
+public class PersonController {
+
+    List<Person> personRepository;
+
+    @PostConstruct
+    public void init() {
+        // @formatter:off
+        personRepository = new ArrayList<>(Arrays.asList(
+            new Person(1, "Jhon", "jhon@test.com", 20, LocalDate.of(2019, 9, 9), BigDecimal.valueOf(1000)), 
+            new Person(2, "Jhon", "jhon1@test.com", 20, LocalDate.of(2019, 9, 9), BigDecimal.valueOf(1500)), 
+            new Person(3, "Jhon", null, 20, LocalDate.of(2019, 9, 9), BigDecimal.valueOf(1000)),  
+            new Person(4, "Tom", "tom@test.com", 21, LocalDate.of(2019, 9, 9), BigDecimal.valueOf(1500)), 
+            new Person(5, "Mark", "mark@test.com", 21, LocalDate.of(2019, 9, 9), BigDecimal.valueOf(1200)), 
+            new Person(6, "Julia", "jhon@test.com", 20, LocalDate.of(2019, 9, 9), BigDecimal.valueOf(1000))));
+        // @formatter:on
+
+    }
+
+    @GetMapping("/person/{id}")
+    @ResponseBody
+    public Person findById(@PathVariable final int id) {
+        return personRepository.get(id);
+    }
+
+    @PostMapping("/person")
+    @ResponseStatus(HttpStatus.OK)
+    @ResponseBody
+    public boolean insertPerson(@RequestBody final Person person) {
+        return personRepository.add(person);
+    }
+
+    @GetMapping("/person")
+    @ResponseBody
+    public List<Person> findAll() {
+        return personRepository;
+    }
+
+}

spring-5-reactive/src/main/java/com/baeldung/jsonb/Spring5Application.java

@@ -0,0 +1,30 @@
+package com.baeldung.jsonb;
+
+import java.util.ArrayList;
+import java.util.Collection;
+
+import org.springframework.boot.SpringApplication;
+import org.springframework.boot.autoconfigure.SpringBootApplication;
+import org.springframework.boot.autoconfigure.http.HttpMessageConverters;
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.ComponentScan;
+import org.springframework.http.converter.HttpMessageConverter;
+import org.springframework.http.converter.json.JsonbHttpMessageConverter;
+
+@SpringBootApplication
+@ComponentScan(basePackages = { "com.baeldung.jsonb" })
+public class Spring5Application {
+
+    public static void main(String[] args) {
+        SpringApplication.run(Spring5Application.class, args);
+    }
+
+    @Bean
+    public HttpMessageConverters customConverters() {
+        Collection<HttpMessageConverter<?>> messageConverters = new ArrayList<>();
+        JsonbHttpMessageConverter jsonbHttpMessageConverter = new JsonbHttpMessageConverter();
+        messageConverters.add(jsonbHttpMessageConverter);
+        return new HttpMessageConverters(true, messageConverters);
+    }
+
+}

spring-5-reactive/src/main/java/com/baeldung/jupiter/MethodParameterFactory.java

@@ -0,0 +1,46 @@
+package com.baeldung.jupiter;
+
+import org.springframework.core.MethodParameter;
+import org.springframework.core.annotation.SynthesizingMethodParameter;
+import org.springframework.util.Assert;
+
+import java.lang.reflect.Constructor;
+import java.lang.reflect.Executable;
+import java.lang.reflect.Method;
+import java.lang.reflect.Parameter;
+
+abstract class MethodParameterFactory {
+
+    private MethodParameterFactory() {
+    }
+
+    public static MethodParameter createMethodParameter(Parameter parameter) {
+        Assert.notNull(parameter, "Parameter must not be null");
+        Executable executable = parameter.getDeclaringExecutable();
+        if (executable instanceof Method) {
+            return new MethodParameter((Method) executable, getIndex(parameter));
+        }
+        return new MethodParameter((Constructor<?>) executable, getIndex(parameter));
+    }
+
+    public static SynthesizingMethodParameter createSynthesizingMethodParameter(Parameter parameter) {
+        Assert.notNull(parameter, "Parameter must not be null");
+        Executable executable = parameter.getDeclaringExecutable();
+        if (executable instanceof Method) {
+            return new SynthesizingMethodParameter((Method) executable, getIndex(parameter));
+        }
+        throw new UnsupportedOperationException("Cannot create a SynthesizingMethodParameter for a constructor parameter: " + parameter);
+    }
+
+    private static int getIndex(Parameter parameter) {
+        Assert.notNull(parameter, "Parameter must not be null");
+        Executable executable = parameter.getDeclaringExecutable();
+        Parameter[] parameters = executable.getParameters();
+        for (int i = 0; i < parameters.length; i++) {
+            if (parameters[i] == parameter) {
+                return i;
+            }
+        }
+        throw new IllegalStateException(String.format("Failed to resolve index of parameter [%s] in executable [%s]", parameter, executable.toGenericString()));
+    }
+}

spring-5-reactive/src/main/java/com/baeldung/jupiter/ParameterAutowireUtils.java

@@ -0,0 +1,44 @@
+package com.baeldung.jupiter;
+
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.beans.factory.annotation.Qualifier;
+import org.springframework.beans.factory.annotation.Value;
+import org.springframework.beans.factory.config.DependencyDescriptor;
+import org.springframework.context.ApplicationContext;
+import org.springframework.core.MethodParameter;
+import org.springframework.core.annotation.AnnotatedElementUtils;
+
+import java.lang.annotation.Annotation;
+import java.lang.reflect.AnnotatedElement;
+import java.lang.reflect.Method;
+import java.lang.reflect.Parameter;
+import java.util.Optional;
+
+import static org.springframework.core.annotation.AnnotatedElementUtils.hasAnnotation;
+
+abstract class ParameterAutowireUtils {
+
+    private ParameterAutowireUtils() {
+    }
+
+    public static boolean isAutowirable(Parameter parameter) {
+        return ApplicationContext.class.isAssignableFrom(parameter.getType()) || hasAnnotation(parameter, Autowired.class) || hasAnnotation(parameter, Qualifier.class) || hasAnnotation(parameter, Value.class);
+    }
+
+    public static Object resolveDependency(Parameter parameter, Class<?> containingClass, ApplicationContext applicationContext) {
+
+        boolean required = findMergedAnnotation(parameter, Autowired.class).map(Autowired::required)
+            .orElse(true);
+        MethodParameter methodParameter = (parameter.getDeclaringExecutable() instanceof Method ? MethodParameterFactory.createSynthesizingMethodParameter(parameter) : MethodParameterFactory.createMethodParameter(parameter));
+        DependencyDescriptor descriptor = new DependencyDescriptor(methodParameter, required);
+        descriptor.setContainingClass(containingClass);
+
+        return applicationContext.getAutowireCapableBeanFactory()
+            .resolveDependency(descriptor, null);
+    }
+
+    private static <A extends Annotation> Optional<A> findMergedAnnotation(AnnotatedElement element, Class<A> annotationType) {
+
+        return Optional.ofNullable(AnnotatedElementUtils.findMergedAnnotation(element, annotationType));
+    }
+}

spring-5-reactive/src/main/java/com/baeldung/jupiter/SpringExtension.java

@@ -0,0 +1,94 @@
+package com.baeldung.jupiter;
+
+import java.lang.reflect.Constructor;
+import java.lang.reflect.Executable;
+import java.lang.reflect.Method;
+import java.lang.reflect.Parameter;
+
+import org.junit.jupiter.api.extension.AfterAllCallback;
+import org.junit.jupiter.api.extension.AfterEachCallback;
+import org.junit.jupiter.api.extension.BeforeAllCallback;
+import org.junit.jupiter.api.extension.BeforeEachCallback;
+import org.junit.jupiter.api.extension.ExtensionContext;
+import org.junit.jupiter.api.extension.ParameterContext;
+import org.junit.jupiter.api.extension.ParameterResolutionException;
+import org.junit.jupiter.api.extension.ParameterResolver;
+import org.junit.jupiter.api.extension.TestInstancePostProcessor;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.context.ApplicationContext;
+import org.springframework.core.annotation.AnnotatedElementUtils;
+import org.springframework.test.context.TestContextManager;
+import org.springframework.util.Assert;
+
+public class SpringExtension implements BeforeAllCallback, AfterAllCallback, TestInstancePostProcessor, BeforeEachCallback, AfterEachCallback, ParameterResolver {
+
+    private static final ExtensionContext.Namespace namespace = ExtensionContext.Namespace.create(SpringExtension.class);
+
+    @Override
+    public void beforeAll(ExtensionContext context) throws Exception {
+        getTestContextManager(context).beforeTestClass();
+    }
+
+    @Override
+    public void afterAll(ExtensionContext context) throws Exception {
+        try {
+            getTestContextManager(context).afterTestClass();
+        } finally {
+            context.getStore(namespace)
+                .remove(context.getTestClass()
+                    .get());
+        }
+    }
+
+    @Override
+    public void postProcessTestInstance(Object testInstance, ExtensionContext context) throws Exception {
+        getTestContextManager(context).prepareTestInstance(testInstance);
+    }
+
+    @Override
+    public void beforeEach(ExtensionContext context) throws Exception {
+        Object testInstance = context.getTestInstance();
+        Method testMethod = context.getTestMethod()
+            .get();
+        getTestContextManager(context).beforeTestMethod(testInstance, testMethod);
+    }
+
+    @Override
+    public void afterEach(ExtensionContext context) throws Exception {
+        Object testInstance = context.getTestInstance();
+        Method testMethod = context.getTestMethod()
+            .get();
+        Throwable testException = context.getExecutionException()
+            .orElse(null);
+        getTestContextManager(context).afterTestMethod(testInstance, testMethod, testException);
+    }
+
+    @Override
+    public boolean supportsParameter(ParameterContext parameterContext, ExtensionContext extensionContext) throws ParameterResolutionException {
+        Parameter parameter = parameterContext.getParameter();
+        Executable executable = parameter.getDeclaringExecutable();
+        return ((executable instanceof Constructor) && AnnotatedElementUtils.hasAnnotation(executable, Autowired.class)) || ParameterAutowireUtils.isAutowirable(parameter);
+    }
+
+    @Override
+    public Object resolveParameter(ParameterContext parameterContext, ExtensionContext extensionContext) throws ParameterResolutionException {
+        Parameter parameter = parameterContext.getParameter();
+        Class<?> testClass = extensionContext.getTestClass()
+            .get();
+        ApplicationContext applicationContext = getApplicationContext(extensionContext);
+        return ParameterAutowireUtils.resolveDependency(parameter, testClass, applicationContext);
+    }
+
+    private ApplicationContext getApplicationContext(ExtensionContext context) {
+        return getTestContextManager(context).getTestContext()
+            .getApplicationContext();
+    }
+
+    private TestContextManager getTestContextManager(ExtensionContext context) {
+        Assert.notNull(context, "ExtensionContext must not be null");
+        Class<?> testClass = context.getTestClass()
+            .get();
+        ExtensionContext.Store store = context.getStore(namespace);
+        return store.getOrComputeIfAbsent(testClass, TestContextManager::new, TestContextManager.class);
+    }
+}

spring-5-reactive/src/main/java/com/baeldung/jupiter/SpringJUnit5Config.java

@@ -0,0 +1,39 @@
+package com.baeldung.jupiter;
+
+import org.junit.jupiter.api.extension.ExtendWith;
+import org.springframework.context.ApplicationContextInitializer;
+import org.springframework.context.ConfigurableApplicationContext;
+import org.springframework.core.annotation.AliasFor;
+import org.springframework.test.context.ContextConfiguration;
+
+import java.lang.annotation.*;
+
+@ExtendWith(SpringExtension.class)
+@ContextConfiguration
+@Documented
+@Inherited
+@Retention(RetentionPolicy.RUNTIME)
+@Target(ElementType.TYPE)
+public @interface SpringJUnit5Config {
+
+    @AliasFor(annotation = ContextConfiguration.class, attribute = "classes")
+    Class<?>[] value() default {};
+
+    @AliasFor(annotation = ContextConfiguration.class)
+    Class<?>[] classes() default {};
+
+    @AliasFor(annotation = ContextConfiguration.class)
+    String[] locations() default {};
+
+    @AliasFor(annotation = ContextConfiguration.class)
+    Class<? extends ApplicationContextInitializer<? extends ConfigurableApplicationContext>>[] initializers() default {};
+
+    @AliasFor(annotation = ContextConfiguration.class)
+    boolean inheritLocations() default true;
+
+    @AliasFor(annotation = ContextConfiguration.class)
+    boolean inheritInitializers() default true;
+
+    @AliasFor(annotation = ContextConfiguration.class)
+    String name() default "";
+}

spring-5-reactive/src/main/java/com/baeldung/jupiter/TestConfig.java

@@ -0,0 +1,20 @@
+package com.baeldung.jupiter;
+
+import com.baeldung.web.reactive.Task;
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+import org.springframework.context.support.PropertySourcesPlaceholderConfigurer;
+
+@Configuration
+public class TestConfig {
+
+    @Bean
+    static PropertySourcesPlaceholderConfigurer placeholderConfigurer() {
+        return new PropertySourcesPlaceholderConfigurer();
+    }
+
+    @Bean
+    Task taskName() {
+        return new Task("taskName", 1);
+    }
+}

spring-5-reactive/src/main/java/com/baeldung/persistence/DataSetupBean.java

@@ -0,0 +1,27 @@
+package com.baeldung.persistence;
+
+import static org.apache.commons.lang3.RandomStringUtils.randomAlphabetic;
+
+import java.util.stream.IntStream;
+
+import org.springframework.beans.factory.InitializingBean;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.stereotype.Component;
+
+import com.baeldung.web.Foo;
+
+@Component
+public class DataSetupBean implements InitializingBean {
+
+    @Autowired
+    private FooRepository repo;
+
+    //
+
+    @Override
+    public void afterPropertiesSet() throws Exception {
+        IntStream.range(1, 20)
+            .forEach(i -> repo.save(new Foo(randomAlphabetic(8))));
+    }
+
+}

spring-5-reactive/src/main/java/com/baeldung/persistence/FooRepository.java

@@ -0,0 +1,10 @@
+package com.baeldung.persistence;
+
+import org.springframework.data.jpa.repository.JpaRepository;
+import org.springframework.data.jpa.repository.JpaSpecificationExecutor;
+
+import com.baeldung.web.Foo;
+
+public interface FooRepository extends JpaRepository<Foo, Long>, JpaSpecificationExecutor<Foo> {
+
+}

spring-5-reactive/src/main/java/com/baeldung/security/GreetController.java

@@ -0,0 +1,37 @@
+package com.baeldung.security;
+
+import org.springframework.web.bind.annotation.GetMapping;
+import org.springframework.web.bind.annotation.RestController;
+import reactor.core.publisher.Mono;
+
+import java.security.Principal;
+
+@RestController
+public class GreetController {
+
+    private GreetService greetService;
+
+    public GreetController(GreetService greetService) {
+        this.greetService = greetService;
+    }
+
+    @GetMapping("/")
+    public Mono<String> greet(Mono<Principal> principal) {
+        return principal
+                .map(Principal::getName)
+                .map(name -> String.format("Hello, %s", name));
+    }
+
+    @GetMapping("/admin")
+    public Mono<String> greetAdmin(Mono<Principal> principal) {
+        return principal
+                .map(Principal::getName)
+                .map(name -> String.format("Admin access: %s", name));
+    }
+
+    @GetMapping("/greetService")
+    public Mono<String> greetService() {
+        return greetService.greet();
+    }
+
+}

spring-5-reactive/src/main/java/com/baeldung/security/GreetService.java

@@ -0,0 +1,15 @@
+package com.baeldung.security;
+
+import org.springframework.security.access.prepost.PreAuthorize;
+import org.springframework.stereotype.Service;
+import reactor.core.publisher.Mono;
+
+@Service
+public class GreetService {
+
+    @PreAuthorize("hasRole('ADMIN')")
+    public Mono<String> greet() {
+        return Mono.just("Hello from service!");
+    }
+
+}

spring-5-reactive/src/main/java/com/baeldung/security/SecurityConfig.java

@@ -0,0 +1,42 @@
+package com.baeldung.security;
+
+import org.springframework.context.annotation.Bean;
+import org.springframework.security.config.annotation.method.configuration.EnableReactiveMethodSecurity;
+import org.springframework.security.config.annotation.web.reactive.EnableWebFluxSecurity;
+import org.springframework.security.config.web.server.ServerHttpSecurity;
+import org.springframework.security.core.userdetails.MapReactiveUserDetailsService;
+import org.springframework.security.core.userdetails.User;
+import org.springframework.security.core.userdetails.UserDetails;
+import org.springframework.security.web.server.SecurityWebFilterChain;
+
+@EnableWebFluxSecurity
+@EnableReactiveMethodSecurity
+public class SecurityConfig {
+
+    @Bean
+    public SecurityWebFilterChain securitygWebFilterChain(ServerHttpSecurity http) {
+        return http.authorizeExchange()
+                .pathMatchers("/admin").hasAuthority("ROLE_ADMIN")
+                .anyExchange().authenticated()
+                .and().formLogin()
+                .and().build();
+    }
+
+    @Bean
+    public MapReactiveUserDetailsService userDetailsService() {
+        UserDetails user = User.withDefaultPasswordEncoder()
+                .username("user")
+                .password("password")
+                .roles("USER")
+                .build();
+
+        UserDetails admin = User.withDefaultPasswordEncoder()
+                .username("admin")
+                .password("password")
+                .roles("ADMIN")
+                .build();
+
+        return new MapReactiveUserDetailsService(user, admin);
+    }
+
+}

spring-5-reactive/src/main/java/com/baeldung/web/Foo.java

@@ -0,0 +1,84 @@
+package com.baeldung.web;
+
+import javax.persistence.Entity;
+import javax.persistence.GeneratedValue;
+import javax.persistence.GenerationType;
+import javax.persistence.Id;
+
+@Entity
+public class Foo {
+
+    @Id
+    @GeneratedValue(strategy = GenerationType.AUTO)
+    private long id;
+
+    private String name;
+
+    public Foo() {
+        super();
+    }
+
+    public Foo(final String name) {
+        super();
+
+        this.name = name;
+    }
+
+    public Foo(final long id, final String name) {
+        super();
+
+        this.id = id;
+        this.name = name;
+    }
+
+    // API
+
+    public long getId() {
+        return id;
+    }
+
+    public void setId(final long id) {
+        this.id = id;
+    }
+
+    public String getName() {
+        return name;
+    }
+
+    public void setName(final String name) {
+        this.name = name;
+    }
+
+    //
+
+    @Override
+    public int hashCode() {
+        final int prime = 31;
+        int result = 1;
+        result = prime * result + ((name == null) ? 0 : name.hashCode());
+        return result;
+    }
+
+    @Override
+    public boolean equals(Object obj) {
+        if (this == obj)
+            return true;
+        if (obj == null)
+            return false;
+        if (getClass() != obj.getClass())
+            return false;
+        Foo other = (Foo) obj;
+        if (name == null) {
+            if (other.name != null)
+                return false;
+        } else if (!name.equals(other.name))
+            return false;
+        return true;
+    }
+
+    @Override
+    public String toString() {
+        return "Foo [name=" + name + "]";
+    }
+
+}

spring-5-reactive/src/main/java/com/baeldung/web/FooController.java

@@ -0,0 +1,53 @@
+package com.baeldung.web;
+
+import com.baeldung.persistence.FooRepository;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.data.domain.PageRequest;
+import org.springframework.http.HttpStatus;
+import org.springframework.validation.annotation.Validated;
+import org.springframework.web.bind.annotation.*;
+
+import javax.validation.constraints.Max;
+import javax.validation.constraints.Min;
+import java.util.List;
+
+@RestController("/foos")
+public class FooController {
+
+    @Autowired
+    private FooRepository repo;
+
+    // API - read
+
+    @GetMapping("/foos/{id}")
+    @ResponseBody
+    @Validated
+    public Foo findById(@PathVariable @Min(0) final long id) {
+        return repo.findById(id)
+            .orElse(null);
+    }
+
+    @GetMapping
+    @ResponseBody
+    public List<Foo> findAll() {
+        return repo.findAll();
+    }
+
+    @GetMapping(params = { "page", "size" })
+    @ResponseBody
+    @Validated
+    public List<Foo> findPaginated(@RequestParam("page") @Min(0) final int page, @Max(100) @RequestParam("size") final int size) {
+        return repo.findAll(PageRequest.of(page, size))
+            .getContent();
+    }
+
+    // API - write
+
+    @PutMapping("/foos/{id}")
+    @ResponseStatus(HttpStatus.OK)
+    @ResponseBody
+    public Foo update(@PathVariable("id") final String id, @RequestBody final Foo foo) {
+        return foo;
+    }
+
+}

spring-5-reactive/src/main/java/com/baeldung/web/PathPatternController.java

@@ -0,0 +1,39 @@
+package com.baeldung.web;
+
+import org.springframework.web.bind.annotation.GetMapping;
+import org.springframework.web.bind.annotation.PathVariable;
+import org.springframework.web.bind.annotation.RestController;
+
+@RestController
+public class PathPatternController {
+
+    @GetMapping("/spring5/{*id}")
+    public String URIVariableHandler(@PathVariable String id) {
+        return id;
+    }
+
+    @GetMapping("/s?ring5")
+    public String wildcardTakingExactlyOneChar() {
+        return "/s?ring5";
+    }
+
+    @GetMapping("/spring5/*id")
+    public String wildcardTakingZeroOrMoreChar() {
+        return "/spring5/*id";
+    }
+
+    @GetMapping("/resources/**")
+    public String wildcardTakingZeroOrMorePathSegments() {
+        return "/resources/**";
+    }
+
+    @GetMapping("/{baeldung:[a-z]+}")
+    public String regexInPathVariable(@PathVariable String baeldung) {
+        return baeldung;
+    }
+
+    @GetMapping("/{var1}_{var2}")
+    public String multiplePathVariablesInSameSegment(@PathVariable String var1, @PathVariable String var2) {
+        return "Two variables are var1=" + var1 + " and var2=" + var2;
+    }
+}

spring-5-reactive/src/main/java/com/baeldung/web/reactive/Task.java

@@ -0,0 +1,28 @@
+package com.baeldung.web.reactive;
+
+import com.fasterxml.jackson.annotation.JsonProperty;
+
+public class Task {
+
+    private final String name;
+
+    private final int id;
+
+    public Task(@JsonProperty("name") String name, @JsonProperty("id") int id) {
+        this.name = name;
+        this.id = id;
+    }
+
+    public String getName() {
+        return this.name;
+    }
+
+    public int getId() {
+        return this.id;
+    }
+
+    @Override
+    public String toString() {
+        return "Task{" + "name='" + name + '\'' + ", id=" + id + '}';
+    }
+}

spring-5-reactive/src/main/java/com/baeldung/web/reactive/client/WebClientController.java

@@ -0,0 +1,85 @@
+package com.baeldung.web.reactive.client;
+
+import org.reactivestreams.Publisher;
+import org.reactivestreams.Subscriber;
+import org.springframework.http.*;
+import org.springframework.http.client.reactive.ClientHttpRequest;
+import org.springframework.util.LinkedMultiValueMap;
+import org.springframework.util.MultiValueMap;
+import org.springframework.web.bind.annotation.GetMapping;
+import org.springframework.web.bind.annotation.ResponseStatus;
+import org.springframework.web.bind.annotation.RestController;
+import org.springframework.web.reactive.function.BodyInserter;
+import org.springframework.web.reactive.function.BodyInserters;
+import org.springframework.web.reactive.function.client.WebClient;
+import reactor.core.publisher.Mono;
+
+import java.net.URI;
+import java.nio.charset.Charset;
+import java.time.ZonedDateTime;
+import java.util.Collections;
+
+@RestController
+public class WebClientController {
+
+    @ResponseStatus(HttpStatus.OK)
+    @GetMapping("/resource")
+    public void getResource() {
+    }
+
+    public void demonstrateWebClient() {
+        // request
+        WebClient.UriSpec<WebClient.RequestBodySpec> request1 = createWebClientWithServerURLAndDefaultValues().method(HttpMethod.POST);
+        WebClient.UriSpec<WebClient.RequestBodySpec> request2 = createWebClientWithServerURLAndDefaultValues().post();
+
+        // request body specifications
+        WebClient.RequestBodySpec uri1 = createWebClientWithServerURLAndDefaultValues().method(HttpMethod.POST)
+            .uri("/resource");
+        WebClient.RequestBodySpec uri2 = createWebClientWithServerURLAndDefaultValues().post()
+            .uri(URI.create("/resource"));
+
+        // request header specification
+        WebClient.RequestHeadersSpec<?> requestSpec1 = uri1.body(BodyInserters.fromPublisher(Mono.just("data"), String.class));
+        WebClient.RequestHeadersSpec<?> requestSpec2 = uri2.body(BodyInserters.fromObject("data"));
+
+        // inserters
+        BodyInserter<Publisher<String>, ReactiveHttpOutputMessage> inserter1 = BodyInserters
+                .fromPublisher(Subscriber::onComplete, String.class);
+
+        LinkedMultiValueMap<String, String> map = new LinkedMultiValueMap<>();
+        map.add("key1", "value1");
+        map.add("key2", "value2");
+
+        BodyInserter<MultiValueMap<String, ?>, ClientHttpRequest> inserter2 = BodyInserters.fromMultipartData(map);
+        BodyInserter<String, ReactiveHttpOutputMessage> inserter3 = BodyInserters.fromObject("body");
+
+        // responses
+        WebClient.ResponseSpec response1 = uri1.body(inserter3)
+            .header(HttpHeaders.CONTENT_TYPE, MediaType.APPLICATION_JSON_VALUE)
+            .accept(MediaType.APPLICATION_JSON, MediaType.APPLICATION_XML)
+            .acceptCharset(Charset.forName("UTF-8"))
+            .ifNoneMatch("*")
+            .ifModifiedSince(ZonedDateTime.now())
+            .retrieve();
+        WebClient.ResponseSpec response2 = requestSpec2.retrieve();
+
+    }
+
+    private WebClient createWebClient() {
+        return WebClient.create();
+    }
+
+    private WebClient createWebClientWithServerURL() {
+        return WebClient.create("http://localhost:8081");
+    }
+
+    private WebClient createWebClientWithServerURLAndDefaultValues() {
+        return WebClient.builder()
+            .baseUrl("http://localhost:8081")
+            .defaultCookie("cookieKey", "cookieValue")
+            .defaultHeader(HttpHeaders.CONTENT_TYPE, MediaType.APPLICATION_JSON_VALUE)
+            .defaultUriVariables(Collections.singletonMap("url", "http://localhost:8080"))
+            .build();
+    }
+
+}

spring-5-reactive/src/main/resources/application.properties

@@ -0,0 +1,3 @@
+server.port=8081
+
+logging.level.root=INFO

spring-5-reactive/src/main/resources/files/hello.txt

@@ -0,0 +1 @@
+hello

spring-5-reactive/src/main/resources/files/test/test.txt

@@ -0,0 +1 @@
+test

spring-5-reactive/src/main/webapp/WEB-INF/web.xml

@@ -0,0 +1,21 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<web-app xmlns="http://xmlns.jcp.org/xml/ns/javaee"
+         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+         xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee http://xmlns.jcp.org/xml/ns/javaee/web-app_3_1.xsd"
+         version="3.1">
+
+    <display-name>Spring Functional Application</display-name>
+
+    <servlet>
+        <servlet-name>functional</servlet-name>
+        <servlet-class>com.baeldung.functional.RootServlet</servlet-class>
+        <load-on-startup>1</load-on-startup>
+        <async-supported>true</async-supported>
+    </servlet>
+    <servlet-mapping>
+        <servlet-name>functional</servlet-name>
+        <url-pattern>/</url-pattern>
+    </servlet-mapping>
+
+
+</web-app>