add new package

2024-04-30 11:54:43 -04:00
parent 6b33c0d65d
commit 99259d231b
291 changed files with 7240 additions and 0 deletions
@@ -0,0 +1,7 @@
+### Relevant Articles:
+- [Service Locator Pattern and Java Implementation](https://www.baeldung.com/java-service-locator-pattern)
+- [The DAO Pattern in Java](https://www.baeldung.com/java-dao-pattern)
+- [DAO vs Repository Patterns](https://www.baeldung.com/java-dao-vs-repository)
+- [Difference Between MVC and MVP Patterns](https://www.baeldung.com/mvc-vs-mvp-pattern)
+- [The DTO Pattern (Data Transfer Object)](https://www.baeldung.com/java-dto-pattern)
+- [SEDA With Spring Integration and Apache Camel](https://www.baeldung.com/spring-apache-camel-seda-integration)
@@ -0,0 +1,77 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project xmlns="http://maven.apache.org/POM/4.0.0"
+    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+    xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+    <modelVersion>4.0.0</modelVersion>
+    <artifactId>design-patterns-architectural</artifactId>
+    <version>1.0</version>
+    <name>design-patterns-architectural</name>
+    <packaging>jar</packaging>
+
+    <parent>
+        <groupId>com.baeldung</groupId>
+        <artifactId>patterns-modules</artifactId>
+        <version>1.0.0-SNAPSHOT</version>
+    </parent>
+
+    <dependencies>
+        <dependency>
+            <groupId>org.springframework.boot</groupId>
+            <artifactId>spring-boot-starter-web</artifactId>
+            <version>${spring-boot.version}</version>
+        </dependency>
+        <dependency>
+            <groupId>org.springframework.boot</groupId>
+            <artifactId>spring-boot-starter-test</artifactId>
+            <version>${spring-boot.version}</version>
+        </dependency>
+        <dependency>
+            <groupId>io.rest-assured</groupId>
+            <artifactId>rest-assured</artifactId>
+            <version>${rest-assured.version}</version>
+        </dependency>
+        <dependency>
+            <groupId>org.hibernate</groupId>
+            <artifactId>hibernate-core</artifactId>
+            <version>${hibernate-core.version}</version>
+        </dependency>
+        <dependency>
+            <groupId>mysql</groupId>
+            <artifactId>mysql-connector-java</artifactId>
+            <version>${mysql-connector.version}</version>
+            <type>jar</type>
+        </dependency>
+        <dependency>
+            <groupId>org.springframework.boot</groupId>
+            <artifactId>spring-boot-starter-integration</artifactId>
+            <version>${spring-boot-starter-integration.version}</version>
+        </dependency>
+        <dependency>
+            <groupId>org.springframework.integration</groupId>
+            <artifactId>spring-integration-test</artifactId>
+            <version>${spring-integration-test.version}</version>
+        </dependency>
+        <dependency>
+            <groupId>org.apache.camel</groupId>
+            <artifactId>camel-core</artifactId>
+            <version>${camel-core.version}</version>
+        </dependency>
+        <dependency>
+            <groupId>org.apache.camel</groupId>
+            <artifactId>camel-test-junit5</artifactId>
+            <version>${camel-test-junit5.version}</version>
+        </dependency>
+    </dependencies>
+
+    <properties>
+        <hibernate-core.version>5.2.16.Final</hibernate-core.version>
+        <mysql-connector.version>6.0.6</mysql-connector.version>
+        <spring-boot.version>2.7.5</spring-boot.version>
+        <rest-assured.version>5.3.0</rest-assured.version>
+        <spring-boot-starter-integration.version>2.7.5</spring-boot-starter-integration.version>
+        <spring-integration-test.version>5.5.14</spring-integration-test.version>
+        <camel-core.version>3.20.4</camel-core.version>
+        <camel-test-junit5.version>3.14.0</camel-test-junit5.version>
+    </properties>
+
+</project>
@@ -0,0 +1,12 @@
+package com.baeldung.dtopattern;
+
+import org.springframework.boot.SpringApplication;
+import org.springframework.boot.autoconfigure.SpringBootApplication;
+
+@SpringBootApplication
+public class Main {
+    public static void main(String[] args) {
+        SpringApplication.run(Main.class, args);
+    }
+}
+
@@ -0,0 +1,28 @@
+package com.baeldung.dtopattern.api;
+
+import com.baeldung.dtopattern.domain.Role;
+import com.baeldung.dtopattern.domain.User;
+import org.springframework.stereotype.Component;
+
+import java.util.ArrayList;
+import java.util.List;
+
+import static java.util.stream.Collectors.toList;
+
+@Component
+class Mapper {
+    public UserDTO toDto(User user) {
+        String name = user.getName();
+        List<String> roles = user
+                .getRoles()
+                .stream()
+                .map(Role::getName)
+                .collect(toList());
+
+        return new UserDTO(name, roles);
+    }
+
+    public User toUser(UserCreationDTO userDTO) {
+        return new User(userDTO.getName(), userDTO.getPassword(), new ArrayList<>());
+    }
+}
@@ -0,0 +1,51 @@
+package com.baeldung.dtopattern.api;
+
+import com.baeldung.dtopattern.domain.RoleService;
+import com.baeldung.dtopattern.domain.User;
+import com.baeldung.dtopattern.domain.UserService;
+import org.springframework.web.bind.annotation.*;
+
+import java.util.List;
+
+import static java.util.stream.Collectors.toList;
+
+@RestController
+@RequestMapping("/users")
+class UserController {
+
+    private UserService userService;
+    private RoleService roleService;
+    private Mapper mapper;
+
+    public UserController(UserService userService,  RoleService roleService, Mapper mapper) {
+        this.userService = userService;
+        this.roleService = roleService;
+        this.mapper = mapper;
+    }
+
+    @GetMapping
+    @ResponseBody
+    public List<UserDTO> getUsers() {
+        return userService.getAll()
+            .stream()
+            .map(mapper::toDto)
+            .collect(toList());
+    }
+
+
+    @PostMapping
+    @ResponseBody
+    public UserIdDTO create(@RequestBody UserCreationDTO userDTO) {
+        User user = mapper.toUser(userDTO);
+
+        userDTO.getRoles()
+                .stream()
+                .map(role -> roleService.getOrCreate(role))
+                .forEach(user::addRole);
+
+        userService.save(user);
+
+        return new UserIdDTO(user.getId());
+    }
+
+}
@@ -0,0 +1,36 @@
+package com.baeldung.dtopattern.api;
+
+import java.util.List;
+
+public class UserCreationDTO {
+
+    private String name;
+    private String password;
+    private List<String> roles;
+
+    UserCreationDTO() {}
+
+    public String getName() {
+        return name;
+    }
+
+    public String getPassword() {
+        return password;
+    }
+
+    public List<String> getRoles() {
+        return roles;
+    }
+
+    void setName(String name) {
+        this.name = name;
+    }
+
+    void setPassword(String password) {
+        this.password = password;
+    }
+
+    void setRoles(List<String> roles) {
+        this.roles = roles;
+    }
+}
@@ -0,0 +1,22 @@
+package com.baeldung.dtopattern.api;
+
+import java.util.List;
+
+public class UserDTO {
+    private String name;
+    private List<String> roles;
+
+    public UserDTO(String name, List<String> roles) {
+        this.name = name;
+        this.roles = roles;
+    }
+
+    public String getName() {
+        return name;
+    }
+
+    public List<String> getRoles() {
+        return roles;
+    }
+
+}
@@ -0,0 +1,14 @@
+package com.baeldung.dtopattern.api;
+
+public class UserIdDTO {
+
+    private String id;
+
+    public UserIdDTO(String id) {
+        this.id = id;
+    }
+
+    public String getId() {
+        return id;
+    }
+}
@@ -0,0 +1,49 @@
+package com.baeldung.dtopattern.domain;
+
+import org.springframework.stereotype.Service;
+
+import java.util.*;
+
+@Service
+class InMemoryRepository implements UserRepository, RoleRepository {
+
+    private Map<String, User> users = new LinkedHashMap<>();
+    private Map<String, Role> roles = new LinkedHashMap<>();
+
+    @Override
+    public List<User> getAll() {
+        return new ArrayList<>(users.values());
+    }
+
+    @Override
+    public void save(User user) {
+        user.setId(UUID.randomUUID().toString());
+        users.put(user.getId(), user);
+    }
+
+    @Override
+    public void save(Role role) {
+        role.setId(UUID.randomUUID().toString());
+        roles.put(role.getId(), role);
+    }
+
+    @Override
+    public Role getRoleById(String id) {
+        return roles.get(id);
+    }
+
+    @Override
+    public Role getRoleByName(String name) {
+        return roles.values()
+            .stream()
+            .filter(role -> role.getName().equalsIgnoreCase(name))
+            .findFirst()
+            .orElse(null);
+    }
+
+    @Override
+    public void deleteAll() {
+        users.clear();
+        roles.clear();
+    }
+}
@@ -0,0 +1,28 @@
+package com.baeldung.dtopattern.domain;
+
+import java.util.Objects;
+
+public class Role {
+    private String id;
+    private String name;
+
+    public Role(String name) {
+        this.name = Objects.requireNonNull(name);
+    }
+
+    public String getId() {
+        return id;
+    }
+
+    void setId(String id) {
+        this.id = Objects.requireNonNull(id);
+    }
+
+    public String getName() {
+        return name;
+    }
+
+    public void setName(String name) {
+        this.name = Objects.requireNonNull(name);
+    }
+}
@@ -0,0 +1,7 @@
+package com.baeldung.dtopattern.domain;
+
+public interface RoleRepository {
+    Role getRoleById(String id);
+    Role getRoleByName(String name);
+    void save(Role role);
+}
@@ -0,0 +1,32 @@
+package com.baeldung.dtopattern.domain;
+
+import org.springframework.stereotype.Service;
+
+import java.util.Objects;
+
+@Service
+public class RoleService {
+
+    private RoleRepository repository;
+
+    public RoleService(RoleRepository repository) {
+        this.repository = repository;
+    }
+
+    public Role getOrCreate(String name) {
+        Role role = repository.getRoleByName(name);
+
+        if (role == null) {
+            role = new Role(name);
+            repository.save(role);
+        }
+
+        return role;
+    }
+
+    public void save(Role role) {
+        Objects.requireNonNull(role);
+        repository.save(role);
+    }
+
+}
@@ -0,0 +1,80 @@
+package com.baeldung.dtopattern.domain;
+
+import javax.crypto.*;
+import javax.crypto.spec.SecretKeySpec;
+import java.nio.charset.StandardCharsets;
+import java.security.InvalidKeyException;
+import java.security.NoSuchAlgorithmException;
+import java.util.Collections;
+import java.util.List;
+import java.util.Objects;
+
+public class User {
+
+    private static SecretKeySpec KEY = initKey();
+
+    static SecretKeySpec initKey(){
+        try {
+            SecretKey secretKey = KeyGenerator.getInstance("AES").generateKey();
+            return new SecretKeySpec(secretKey.getEncoded(), "AES");
+        } catch (NoSuchAlgorithmException ex) {
+            return null;
+        }
+    }
+
+    private String id;
+    private String name;
+    private String password;
+    private List<Role> roles;
+
+    public User(String name, String password, List<Role> roles) {
+        this.name = Objects.requireNonNull(name);
+        this.password = this.encrypt(password);
+        this.roles = Objects.requireNonNull(roles);
+    }
+
+    public String getName() {
+        return name;
+    }
+
+    public void setName(String name) {
+        this.name = name;
+    }
+
+    public String getPassword() {
+        return password;
+    }
+
+    public void setPassword(String password) {
+        this.password = password;
+    }
+
+    public void addRole(Role role) {
+        roles.add(role);
+    }
+
+    public List<Role> getRoles() {
+        return Collections.unmodifiableList(roles);
+    }
+
+    public String getId() {
+        return id;
+    }
+
+    void setId(String id) {
+        this.id = id;
+    }
+
+    String encrypt(String password) {
+        Objects.requireNonNull(password);
+        try {
+            Cipher cipher = Cipher.getInstance("AES");
+            cipher.init(Cipher.ENCRYPT_MODE, KEY);
+            final byte[] encryptedBytes = cipher.doFinal(password.getBytes(StandardCharsets.UTF_8));
+            return new String(encryptedBytes, StandardCharsets.UTF_8);
+        } catch (NoSuchAlgorithmException | NoSuchPaddingException | InvalidKeyException | IllegalBlockSizeException | BadPaddingException e) {
+            // do nothing
+            return "";
+        }
+    }
+}
@@ -0,0 +1,9 @@
+package com.baeldung.dtopattern.domain;
+
+import java.util.List;
+
+public interface UserRepository {
+    List<User> getAll();
+    void save(User user);
+    void deleteAll();
+}
@@ -0,0 +1,25 @@
+package com.baeldung.dtopattern.domain;
+
+import org.springframework.stereotype.Service;
+
+import java.util.List;
+import java.util.Objects;
+
+@Service
+public class UserService {
+
+    private UserRepository repository;
+
+    public UserService(UserRepository repository) {
+        this.repository = repository;
+    }
+
+    public List<User> getAll() {
+        return repository.getAll();
+    }
+
+    public void save(User user) {
+        Objects.requireNonNull(user);
+        repository.save(user);
+    }
+}
@@ -0,0 +1,24 @@
+package com.baeldung.mvc_mvp.mvc;
+
+public class MvcMainClass {
+    
+    public static void main(String[] args) {
+        
+        Product model = retrieveProductFromDatabase();
+        ProductView view = new ProductView();
+        model.setView(view);
+        model.showProduct();
+        
+        ProductController controller = new ProductController(model);
+        controller.setName("SmartPhone");
+        model.showProduct();
+    }
+    
+    private static Product retrieveProductFromDatabase() {
+        Product product = new Product();
+        product.setName("Mobile");
+        product.setDescription("New Brand");
+        product.setPrice(1000.0);
+        return product;
+    }
+}
@@ -0,0 +1,45 @@
+package com.baeldung.mvc_mvp.mvc;
+
+public class Product {
+    private String name;
+    private String description;
+    private Double price;
+    private ProductView view;
+    
+    public String getName() {
+        return name;
+    }
+    
+    public void setName(String name) {
+        this.name = name;
+    }
+    
+    public String getDescription() {
+        return description;
+    }
+    
+    public void setDescription(String description) {
+        this.description = description;
+    }
+    
+    public Double getPrice() {
+        return price;
+    }
+    
+    public void setPrice(Double price) {
+        this.price = price;
+    }
+    
+    public ProductView getView() {
+        return view;
+    }
+    
+    public void setView(ProductView view) {
+        this.view = view;
+    }
+    
+    public void showProduct() {
+        view.printProductDetails(name, description, price);
+    }
+    
+}
@@ -0,0 +1,34 @@
+package com.baeldung.mvc_mvp.mvc;
+
+public class ProductController {
+    private final Product product;
+    
+    public ProductController(Product product) {
+        this.product = product;
+    }
+    
+    public String getName() {
+        return product.getName();
+    }
+    
+    public void setName(String name) {
+        product.setName(name);
+    }
+    
+    public String getDescription() {
+        return product.getDescription();
+    }
+    
+    public void setDescription(String description) {
+        product.setDescription(description);
+    }
+    
+    public Double getPrice() {
+        return product.getPrice();
+    }
+    
+    public void setPrice(Double price) {
+        product.setPrice(price);
+    }
+    
+}
@@ -0,0 +1,15 @@
+package com.baeldung.mvc_mvp.mvc;
+
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+public class ProductView {
+    private static Logger log = LoggerFactory.getLogger(ProductView.class);
+    
+    public void printProductDetails(String name, String description, Double price) {
+        log.info("Product details:");
+        log.info("product Name: " + name);
+        log.info("product Description: " + description);
+        log.info("product price: " + price);
+    }
+}
@@ -0,0 +1,22 @@
+package com.baeldung.mvc_mvp.mvp;
+
+public class MvpMainClass {
+    
+    public static void main(String[] args) {
+        
+        Product model = retrieveProductFromDatabase();
+        ProductView view = new ProductView();
+        ProductPresenter presenter = new ProductPresenter(model, view);
+        presenter.showProduct();
+        presenter.setName("SmartPhone");
+        presenter.showProduct();
+    }
+    
+    private static Product retrieveProductFromDatabase() {
+        Product product = new Product();
+        product.setName("Mobile");
+        product.setDescription("New Brand");
+        product.setPrice(1000.0);
+        return product;
+    }
+}
@@ -0,0 +1,32 @@
+package com.baeldung.mvc_mvp.mvp;
+
+public class Product {
+    private String name;
+    private String description;
+    private Double price;
+    
+    public String getName() {
+        return name;
+    }
+    
+    public void setName(String name) {
+        this.name = name;
+    }
+    
+    public String getDescription() {
+        return description;
+    }
+    
+    public void setDescription(String description) {
+        this.description = description;
+    }
+    
+    public Double getPrice() {
+        return price;
+    }
+    
+    public void setPrice(Double price) {
+        this.price = price;
+    }
+    
+}
@@ -0,0 +1,40 @@
+package com.baeldung.mvc_mvp.mvp;
+
+public class ProductPresenter {
+    private final Product product;
+    private final ProductView view;
+    
+    public ProductPresenter(Product product, ProductView view) {
+        this.product = product;
+        this.view = view;
+    }
+    
+    public String getName() {
+        return product.getName();
+    }
+    
+    public void setName(String name) {
+        product.setName(name);
+    }
+    
+    public String getDescription() {
+        return product.getDescription();
+    }
+    
+    public void setDescription(String description) {
+        product.setDescription(description);
+    }
+    
+    public Double getProductPrice() {
+        return product.getPrice();
+    }
+    
+    public void setPrice(Double price) {
+        product.setPrice(price);
+    }
+    
+    public void showProduct() {
+        view.printProductDetails(product.getName(), product.getDescription(), product.getPrice());
+    }
+    
+}
@@ -0,0 +1,15 @@
+package com.baeldung.mvc_mvp.mvp;
+
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+public class ProductView {
+    private static Logger log = LoggerFactory.getLogger(ProductView.class);
+    
+    public void printProductDetails(String name, String description, Double price) {
+        log.info("Product details:");
+        log.info("product Name: " + name);
+        log.info("product Description: " + description);
+        log.info("product price: " + price);
+    }
+}
@@ -0,0 +1,37 @@
+package com.baeldung.repositoryvsdaopattern;
+
+import java.util.Date;
+
+public class Tweet {
+    
+    private String email;
+    
+    private String tweetText;
+    
+    private Date dateCreated;
+
+    public String getEmail() {
+        return email;
+    }
+
+    public void setEmail(String email) {
+        this.email = email;
+    }
+
+    public String getTweetText() {
+        return tweetText;
+    }
+
+    public void setTweetText(String tweetText) {
+        this.tweetText = tweetText;
+    }
+
+    public Date getDateCreated() {
+        return dateCreated;
+    }
+
+    public void setDateCreated(Date dateCreated) {
+        this.dateCreated = dateCreated;
+    }
+
+}
@@ -0,0 +1,9 @@
+package com.baeldung.repositoryvsdaopattern;
+
+import java.util.List;
+
+public interface TweetDao {
+
+    List<Tweet> fetchTweets(String email);
+    
+}
@@ -0,0 +1,17 @@
+package com.baeldung.repositoryvsdaopattern;
+
+import java.util.ArrayList;
+import java.util.List;
+
+public class TweetDaoImpl implements TweetDao {
+
+    @Override
+    public List<Tweet> fetchTweets(String email) {
+        List<Tweet> tweets = new ArrayList<Tweet>();
+        
+        //call Twitter API and prepare Tweet object
+        
+        return tweets;
+    }
+
+}
@@ -0,0 +1,51 @@
+package com.baeldung.repositoryvsdaopattern;
+
+public class User {
+    
+    private Long id;
+    private String userName;
+    private String firstName;
+    private String lastName;
+    private String email;
+    
+    public Long getId() {
+        return id;
+    }
+
+    public void setId(Long id) {
+        this.id = id;
+    }
+
+    public String getUserName() {
+        return userName;
+    }
+    
+    public void setUserName(String userName) {
+        this.userName = userName;
+    }
+    
+    public String getFirstName() {
+        return firstName;
+    }
+    
+    public void setFirstName(String firstName) {
+        this.firstName = firstName;
+    }
+    
+    public String getLastName() {
+        return lastName;
+    }
+    
+    public void setLastName(String lastName) {
+        this.lastName = lastName;
+    }
+    
+    public String getEmail() {
+        return email;
+    }
+    
+    public void setEmail(String email) {
+        this.email = email;
+    }
+    
+}
@@ -0,0 +1,13 @@
+package com.baeldung.repositoryvsdaopattern;
+
+public interface UserDao {
+    
+    void create(User user);
+    
+    User read(Long id);
+    
+    void update(User user);
+    
+    void delete(String userName);
+
+}
@@ -0,0 +1,33 @@
+package com.baeldung.repositoryvsdaopattern;
+
+import javax.persistence.EntityManager;
+
+public class UserDaoImpl implements UserDao {
+
+    private final EntityManager entityManager;
+    
+    public UserDaoImpl(EntityManager entityManager) {
+        this.entityManager = entityManager;
+    }
+
+    @Override 
+    public void create(User user) { 
+        entityManager.persist(user); 
+    }
+    
+    @Override
+    public User read(Long id) {
+        return entityManager.find(User.class, id);
+    } 
+
+    @Override
+    public void update(User user) {
+        
+    }
+
+    @Override
+    public void delete(String userName) {
+        
+    }
+
+}
@@ -0,0 +1,21 @@
+package com.baeldung.repositoryvsdaopattern;
+
+import java.util.List;
+
+public interface UserRepository {
+    
+    User get(Long id);
+    
+    void add(User user);
+    
+    void update(User user);
+    
+    void remove(User user);
+    
+    User findByUserName(String userName);
+    
+    User findByEmail(String email);
+    
+    List<Tweet> fetchTweets(User user);
+    
+}
@@ -0,0 +1,51 @@
+package com.baeldung.repositoryvsdaopattern;
+
+import java.util.List;
+
+public class UserRepositoryImpl implements UserRepository {
+
+    private UserDaoImpl userDaoImpl;
+    private TweetDaoImpl tweetDaoImpl;
+    
+    @Override
+    public User get(Long id) {
+        UserSocialMedia user = (UserSocialMedia) userDaoImpl.read(id);
+        
+        List<Tweet> tweets = tweetDaoImpl.fetchTweets(user.getEmail());
+        user.setTweets(tweets);
+        
+        return user;
+    }
+    
+    @Override
+    public void add(User user) {
+        userDaoImpl.create(user);
+    }
+
+    @Override
+    public void remove(User user) {
+        
+    }
+
+    @Override
+    public void update(User user) {
+        
+    }
+
+    @Override
+    public List<Tweet> fetchTweets(User user) {
+        return tweetDaoImpl.fetchTweets(user.getEmail());
+        
+    }
+    
+    @Override
+    public User findByUserName(String userName) {
+        return null;
+    }
+    
+    @Override
+    public User findByEmail(String email) {
+        return null;
+    }
+
+}
@@ -0,0 +1,17 @@
+package com.baeldung.repositoryvsdaopattern;
+
+import java.util.List;
+
+public class UserSocialMedia extends User {
+    
+    private List<Tweet> tweets;
+    
+    public List<Tweet> getTweets() {
+        return tweets;
+    }
+
+    public void setTweets(List<Tweet> tweets) {
+        this.tweets = tweets;
+    }
+
+}
@@ -0,0 +1,48 @@
+package com.baeldung.seda.apachecamel;
+
+import java.util.List;
+import java.util.function.Function;
+import java.util.stream.Collectors;
+
+import org.apache.camel.Exchange;
+import org.apache.camel.builder.ExpressionBuilder;
+import org.apache.camel.builder.RouteBuilder;
+import org.apache.camel.processor.aggregate.AbstractListAggregationStrategy;
+
+public class WordCountRoute extends RouteBuilder {
+
+    public static final String receiveTextUri = "seda:receiveText?concurrentConsumers=5";
+    public static final String splitWordsUri = "seda:splitWords?concurrentConsumers=5";
+    public static final String toLowerCaseUri = "seda:toLowerCase?concurrentConsumers=5";
+    public static final String countWordsUri = "seda:countWords?concurrentConsumers=5";
+    public static final String returnResponse = "mock:result";
+
+    @Override
+    public void configure() throws Exception {
+
+        from(receiveTextUri).to(splitWordsUri);
+
+        from(splitWordsUri).transform(ExpressionBuilder.bodyExpression(s -> s.toString()
+            .split(" ")))
+          .to(toLowerCaseUri);
+
+        from(toLowerCaseUri).split(body(), new StringListAggregationStrategy())
+          .transform(ExpressionBuilder.bodyExpression(body -> body.toString()
+            .toLowerCase()))
+          .end()
+          .to(countWordsUri);
+
+        from(countWordsUri).transform(ExpressionBuilder.bodyExpression(List.class, body -> body.stream()
+            .collect(Collectors.groupingBy(Function.identity(), Collectors.counting()))))
+          .to(returnResponse);
+    }
+}
+
+class StringListAggregationStrategy extends AbstractListAggregationStrategy<String> {
+    @Override
+    public String getValue(Exchange exchange) {
+        return exchange.getIn()
+          .getBody(String.class);
+    }
+
+}
@@ -0,0 +1,56 @@
+package com.baeldung.seda.springintegration;
+
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+import org.springframework.core.task.TaskExecutor;
+import org.springframework.integration.dsl.MessageChannels;
+import org.springframework.messaging.MessageChannel;
+
+@Configuration
+public class ChannelConfiguration {
+
+    private final TaskExecutor receiveTextChannelThreadPool;
+    private final TaskExecutor splitWordsChannelThreadPool;
+    private final TaskExecutor toLowerCaseChannelThreadPool;
+    private final TaskExecutor countWordsChannelThreadPool;
+    private final TaskExecutor returnResponseChannelThreadPool;
+
+    public ChannelConfiguration(TaskExecutor receiveTextChannelThreadPool, TaskExecutor splitWordsChannelThreadPool, TaskExecutor toLowerCaseChannelThreadPool, TaskExecutor countWordsChannelThreadPool, TaskExecutor returnResponseChannelThreadPool) {
+        this.receiveTextChannelThreadPool = receiveTextChannelThreadPool;
+        this.splitWordsChannelThreadPool = splitWordsChannelThreadPool;
+        this.toLowerCaseChannelThreadPool = toLowerCaseChannelThreadPool;
+        this.countWordsChannelThreadPool = countWordsChannelThreadPool;
+        this.returnResponseChannelThreadPool = returnResponseChannelThreadPool;
+    }
+
+    @Bean(name = "receiveTextChannel")
+    public MessageChannel getReceiveTextChannel() {
+        return MessageChannels.executor("receive-text", receiveTextChannelThreadPool)
+          .get();
+    }
+
+    @Bean(name = "splitWordsChannel")
+    public MessageChannel getSplitWordsChannel() {
+        return MessageChannels.executor("split-words", splitWordsChannelThreadPool)
+          .get();
+    }
+
+    @Bean(name = "toLowerCaseChannel")
+    public MessageChannel getToLowerCaseChannel() {
+        return MessageChannels.executor("to-lower-case", toLowerCaseChannelThreadPool)
+          .get();
+    }
+
+    @Bean(name = "countWordsChannel")
+    public MessageChannel getCountWordsChannel() {
+        return MessageChannels.executor("count-words", countWordsChannelThreadPool)
+          .get();
+    }
+
+    @Bean(name = "returnResponseChannel")
+    public MessageChannel getReturnResponseChannel() {
+        return MessageChannels.executor("return-response", returnResponseChannelThreadPool)
+          .get();
+    }
+
+}
@@ -0,0 +1,81 @@
+package com.baeldung.seda.springintegration;
+
+import java.util.List;
+import java.util.Map;
+import java.util.function.Function;
+import java.util.stream.Collectors;
+
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+import org.springframework.integration.aggregator.MessageGroupProcessor;
+import org.springframework.integration.aggregator.ReleaseStrategy;
+import org.springframework.integration.config.EnableIntegration;
+import org.springframework.integration.dsl.IntegrationFlow;
+import org.springframework.integration.dsl.IntegrationFlows;
+import org.springframework.messaging.Message;
+import org.springframework.messaging.MessageChannel;
+import org.springframework.messaging.support.MessageBuilder;
+
+@Configuration
+@EnableIntegration
+public class IntegrationConfiguration {
+
+    private final MessageChannel receiveTextChannel;
+    private final MessageChannel splitWordsChannel;
+    private final MessageChannel toLowerCaseChannel;
+    private final MessageChannel countWordsChannel;
+    private final MessageChannel returnResponseChannel;
+
+    private final Function<String, String[]> splitWordsFunction = sentence -> sentence.split(" ");
+    private final Function<List<String>, Map<String, Long>> convertArrayListToCountMap = list -> list.stream()
+      .collect(Collectors.groupingBy(Function.identity(), Collectors.counting()));
+    private final Function<String, String> toLowerCase = String::toLowerCase;
+    private final MessageGroupProcessor buildMessageWithListPayload = messageGroup -> MessageBuilder.withPayload(messageGroup.streamMessages()
+        .map(Message::getPayload)
+        .collect(Collectors.toList()))
+      .build();
+    private final ReleaseStrategy listSizeReached = r -> r.size() == r.getSequenceSize();
+
+    public IntegrationConfiguration(MessageChannel receiveTextChannel, MessageChannel splitWordsChannel, MessageChannel toLowerCaseChannel, MessageChannel countWordsChannel, MessageChannel returnResponseChannel) {
+        this.receiveTextChannel = receiveTextChannel;
+        this.splitWordsChannel = splitWordsChannel;
+        this.toLowerCaseChannel = toLowerCaseChannel;
+        this.countWordsChannel = countWordsChannel;
+        this.returnResponseChannel = returnResponseChannel;
+    }
+
+    @Bean
+    public IntegrationFlow receiveText() {
+        return IntegrationFlows.from(receiveTextChannel)
+          .channel(splitWordsChannel)
+          .get();
+    }
+
+    @Bean
+    public IntegrationFlow splitWords() {
+        return IntegrationFlows.from(splitWordsChannel)
+          .transform(splitWordsFunction)
+          .channel(toLowerCaseChannel)
+          .get();
+    }
+
+    @Bean
+    public IntegrationFlow toLowerCase() {
+        return IntegrationFlows.from(toLowerCaseChannel)
+          .split()
+          .transform(toLowerCase)
+          .aggregate(aggregatorSpec -> aggregatorSpec.releaseStrategy(listSizeReached)
+            .outputProcessor(buildMessageWithListPayload))
+          .channel(countWordsChannel)
+          .get();
+    }
+
+    @Bean
+    public IntegrationFlow countWords() {
+        return IntegrationFlows.from(countWordsChannel)
+          .transform(convertArrayListToCountMap)
+          .channel(returnResponseChannel)
+          .get();
+    }
+
+}
@@ -0,0 +1,61 @@
+package com.baeldung.seda.springintegration;
+
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+import org.springframework.core.task.TaskExecutor;
+import org.springframework.scheduling.concurrent.ThreadPoolTaskExecutor;
+
+@Configuration
+public class TaskExecutorConfiguration {
+
+    @Bean("receiveTextChannelThreadPool")
+    public TaskExecutor receiveTextChannelThreadPool() {
+        ThreadPoolTaskExecutor executor = new ThreadPoolTaskExecutor();
+        executor.setCorePoolSize(1);
+        executor.setMaxPoolSize(5);
+        executor.setThreadNamePrefix("receive-text-channel-thread-pool");
+        executor.initialize();
+        return executor;
+    }
+
+    @Bean("splitWordsChannelThreadPool")
+    public TaskExecutor splitWordsChannelThreadPool() {
+        ThreadPoolTaskExecutor executor = new ThreadPoolTaskExecutor();
+        executor.setCorePoolSize(1);
+        executor.setMaxPoolSize(5);
+        executor.setThreadNamePrefix("split-words-channel-thread-pool");
+        executor.initialize();
+        return executor;
+    }
+
+    @Bean("toLowerCaseChannelThreadPool")
+    public TaskExecutor toLowerCaseChannelThreadPool() {
+        ThreadPoolTaskExecutor executor = new ThreadPoolTaskExecutor();
+        executor.setCorePoolSize(1);
+        executor.setMaxPoolSize(5);
+        executor.setThreadNamePrefix("tto-lower-case-channel-thread-pool");
+        executor.initialize();
+        return executor;
+    }
+
+    @Bean("countWordsChannelThreadPool")
+    public TaskExecutor countWordsChannelThreadPool() {
+        ThreadPoolTaskExecutor executor = new ThreadPoolTaskExecutor();
+        executor.setCorePoolSize(1);
+        executor.setMaxPoolSize(5);
+        executor.setThreadNamePrefix("count-words-channel-thread-pool");
+        executor.initialize();
+        return executor;
+    }
+
+    @Bean("returnResponseChannelThreadPool")
+    public TaskExecutor returnResponseChannelThreadPool() {
+        ThreadPoolTaskExecutor executor = new ThreadPoolTaskExecutor();
+        executor.setCorePoolSize(1);
+        executor.setMaxPoolSize(5);
+        executor.setThreadNamePrefix("return-response-channel-thread-pool");
+        executor.initialize();
+        return executor;
+    }
+
+}
@@ -0,0 +1,12 @@
+package com.baeldung.seda.springintegration;
+
+import java.util.Map;
+
+import org.springframework.integration.annotation.Gateway;
+import org.springframework.integration.annotation.MessagingGateway;
+
+@MessagingGateway
+public interface TestGateway {
+    @Gateway(requestChannel = "receiveTextChannel", replyChannel = "returnResponseChannel")
+    public Map<String, Long> countWords(String test);
+}
@@ -0,0 +1,56 @@
+package com.baeldung.dtopattern.api;
+
+import com.baeldung.dtopattern.domain.Role;
+import com.baeldung.dtopattern.domain.User;
+import org.junit.jupiter.api.Test;
+
+import java.util.ArrayList;
+import java.util.Collections;
+import java.util.List;
+
+import static org.junit.jupiter.api.Assertions.*;
+
+class MapperUnitTest {
+
+    @Test
+    void toDto_shouldMapFromDomainToDTO() {
+        String name = "Test";
+        String password = "test";
+        Role admin = new Role("admin");
+        List<String> expectedRoles = Collections.singletonList("admin");
+
+        List<Role> roles = new ArrayList<>();
+        roles.add(admin);
+
+        User user = new User(name, password, roles);
+        Mapper mapper = new Mapper();
+
+        UserDTO dto = mapper.toDto(user);
+
+        assertEquals(name, dto.getName());
+        assertEquals(expectedRoles, dto.getRoles());
+    }
+
+    @Test
+    void toUser_shouldMapFromDTOToDomain() {
+        String name = "Test";
+        String password = "test";
+        String role = "admin";
+
+        UserCreationDTO dto = new UserCreationDTO();
+        dto.setName(name);
+        dto.setPassword(password);
+        dto.setRoles(Collections.singletonList("admin"));
+
+        User expectedUser = new User(name, password, new ArrayList<>());
+
+        Mapper mapper = new Mapper();
+
+        User user = mapper.toUser(dto);
+
+        assertEquals(name, user.getName());
+        assertEquals(expectedUser.getPassword(), user.getPassword());
+        assertEquals(Collections.emptyList(), user.getRoles());
+    }
+
+}
@@ -0,0 +1,80 @@
+package com.baeldung.dtopattern.api;
+
+import com.baeldung.dtopattern.domain.Role;
+import com.baeldung.dtopattern.domain.RoleRepository;
+import com.baeldung.dtopattern.domain.User;
+import com.baeldung.dtopattern.domain.UserRepository;
+import com.fasterxml.jackson.databind.ObjectMapper;
+import io.restassured.http.ContentType;
+import org.junit.jupiter.api.Test;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.boot.test.context.SpringBootTest;
+import org.springframework.boot.test.web.client.TestRestTemplate;
+import org.springframework.boot.web.server.LocalServerPort;
+
+import java.util.Collections;
+
+import static io.restassured.RestAssured.given;
+import static org.hamcrest.CoreMatchers.*;
+import static org.springframework.http.HttpStatus.OK;
+
+@SpringBootTest(webEnvironment = SpringBootTest.WebEnvironment.RANDOM_PORT)
+class UserControllerIntegrationTest {
+
+    @Autowired
+    private TestRestTemplate restTemplate;
+
+    @Autowired
+    private UserRepository userRepository;
+
+    @Autowired
+    private RoleRepository roleRepository;
+
+    @LocalServerPort
+    int port;
+
+    @Autowired
+    private ObjectMapper objectMapper;
+
+    @Test
+    void create_shouldReturnUseId() throws Exception {
+        UserCreationDTO request = new UserCreationDTO();
+        request.setName("User 1");
+        request.setPassword("Test@123456");
+        request.setRoles(Collections.singletonList("admin"));
+
+        given()
+            .contentType(ContentType.JSON)
+            .body(objectMapper.writeValueAsString(request))
+        .when()
+            .port(port)
+            .post("/users")
+        .then()
+            .statusCode(OK.value())
+            .body("id", notNullValue());
+    }
+
+    @Test
+    void getAll_shouldReturnUseDTO() {
+
+        userRepository.deleteAll();
+
+        String roleName = "admin";
+        Role admin = new Role(roleName);
+        roleRepository.save(admin);
+
+        String name = "User 1";
+        User user = new User(name, "Test@123456", Collections.singletonList(admin));
+        userRepository.save(user);
+
+        given()
+            .port(port)
+        .when()
+            .get("/users")
+        .then()
+            .statusCode(OK.value())
+            .body("size()", is(1))
+            .body("[0].name", equalTo(name))
+            .body("[0].roles", hasItem(roleName));
+    }
+}
@@ -0,0 +1,83 @@
+package com.baeldung.dtopattern.domain;
+
+import org.junit.jupiter.api.Test;
+
+import java.util.ArrayList;
+import java.util.Collections;
+import java.util.List;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertNotNull;
+
+class InMemoryRepositoryUnitTest {
+
+    @Test
+    void getAll_shouldReturnAllUsers() {
+
+        String name = "Test";
+        String password = "test123";
+        List<Role> roles = new ArrayList<>();
+
+        User user = new User(name, password, roles);
+        List<User> expectedUsers = Collections.singletonList(user);
+
+        InMemoryRepository repository = new InMemoryRepository();
+        repository.save(user);
+
+        List<User> users = repository.getAll();
+
+        assertEquals(expectedUsers, users);
+    }
+
+    @Test
+    void save_whenSavingUser_shouldSetId() {
+        String name = "Test";
+        String password = "test123";
+        List<Role> roles = new ArrayList<>();
+
+        User user = new User(name, password, roles);
+
+        InMemoryRepository repository = new InMemoryRepository();
+        repository.save(user);
+
+        assertNotNull(user.getId());
+    }
+
+    @Test
+    void save_whenSavingRole_shouldSetId() {
+        String name = "Test";
+        Role role = new Role(name);
+
+        InMemoryRepository repository = new InMemoryRepository();
+        repository.save(role);
+
+        assertNotNull(role.getId());
+    }
+
+    @Test
+    void getRoleById_shouldReturnRoleById() {
+        String name = "Test";
+        Role expectedRole = new Role(name);
+
+        InMemoryRepository repository = new InMemoryRepository();
+        repository.save(expectedRole);
+
+        Role role = repository.getRoleById(expectedRole.getId());
+
+        assertEquals(expectedRole, role);
+    }
+
+    @Test
+    void getRoleByName_shouldReturnRoleByName() {
+        String name = "Test";
+        Role expectedRole = new Role(name);
+
+        InMemoryRepository repository = new InMemoryRepository();
+        repository.save(expectedRole);
+
+        Role role = repository.getRoleByName(name);
+
+        assertEquals(expectedRole, role);
+    }
+
+}
@@ -0,0 +1,38 @@
+package com.baeldung.dtopattern.domain;
+
+import org.junit.jupiter.api.Test;
+
+import java.util.ArrayList;
+
+import static org.junit.jupiter.api.Assertions.*;
+
+class UserUnitTest {
+
+
+    @Test
+    void whenUserIsCreated_shouldEncryptPassword() {
+        User user = new User("Test", "test", new ArrayList<>());
+
+        assertEquals(user.encrypt("test"), user.getPassword());
+        assertNotEquals(user.encrypt("Test"), user.getPassword());
+    }
+
+    @Test
+    void whenUserIsCreated_shouldFailIfNameIsNull() {
+        assertThrows(NullPointerException.class, () ->
+            new User(null, "test", new ArrayList<>()));
+    }
+
+    @Test
+    void whenUserIsCreated_shouldFailIfPasswordIsNull() {
+        assertThrows(NullPointerException.class, () ->
+            new User("Test", null, new ArrayList<>()));
+    }
+
+    @Test
+    void whenUserIsCreated_shouldFailIfRolesIsNull() {
+        assertThrows(NullPointerException.class, () ->
+            new User("Test", "Test", null));
+    }
+
+}
@@ -0,0 +1,48 @@
+package com.baeldung.seda.apachecamel;
+
+import java.util.HashMap;
+import java.util.Map;
+
+import org.apache.camel.RoutesBuilder;
+import org.apache.camel.test.junit5.CamelTestSupport;
+import org.junit.jupiter.api.Test;
+
+import com.baeldung.seda.apachecamel.WordCountRoute;
+
+public class ApacheCamelSedaIntegrationTest extends CamelTestSupport {
+
+    @Test
+    public void givenTextWithCapitalAndSmallCaseAndWithoutDuplicateWords_whenSendingTextToInputUri_thenWordCountReturnedAsMap() throws InterruptedException {
+        Map<String, Long> expected = new HashMap<>();
+        expected.put("my", 1L);
+        expected.put("name", 1L);
+        expected.put("is", 1L);
+        expected.put("hesam", 1L);
+        getMockEndpoint(WordCountRoute.returnResponse).expectedBodiesReceived(expected);
+        template.sendBody(WordCountRoute.receiveTextUri, "My name is Hesam");
+
+        assertMockEndpointsSatisfied();
+    }
+
+    @Test
+    public void givenTextWithDuplicateWords_whenSendingTextToInputUri_thenWordCountReturnedAsMap() throws InterruptedException {
+        Map<String, Long> expected = new HashMap<>();
+        expected.put("the", 3L);
+        expected.put("dog", 1L);
+        expected.put("chased", 1L);
+        expected.put("rabbit", 1L);
+        expected.put("into", 1L);
+        expected.put("jungle", 1L);
+        getMockEndpoint(WordCountRoute.returnResponse).expectedBodiesReceived(expected);
+        template.sendBody(WordCountRoute.receiveTextUri, "the dog chased the rabbit into the jungle");
+
+        assertMockEndpointsSatisfied();
+    }
+
+    @Override
+    protected RoutesBuilder createRouteBuilder() throws Exception {
+        RoutesBuilder wordCountRoute = new WordCountRoute();
+        return wordCountRoute;
+    }
+
+}
@@ -0,0 +1,50 @@
+package com.baeldung.seda.springintegration;
+
+import java.util.HashMap;
+import java.util.Map;
+
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.extension.ExtendWith;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.integration.annotation.IntegrationComponentScan;
+import org.springframework.integration.config.EnableIntegration;
+import org.springframework.test.context.ContextConfiguration;
+import org.springframework.test.context.junit.jupiter.SpringExtension;
+import org.springframework.test.context.support.AnnotationConfigContextLoader;
+
+@ExtendWith(SpringExtension.class)
+@ContextConfiguration(loader = AnnotationConfigContextLoader.class, classes = { TaskExecutorConfiguration.class, ChannelConfiguration.class, IntegrationConfiguration.class })
+@EnableIntegration
+@IntegrationComponentScan(basePackages = { "com.baeldung.seda.springintegration" })
+public class SpringIntegrationSedaIntegrationTest {
+
+    @Autowired
+    TestGateway testGateway;
+
+    @Test
+    void givenTextWithCapitalAndSmallCaseAndWithoutDuplicateWords_whenCallingCountWordOnGateway_thenWordCountReturnedAsMap() {
+        Map<String, Long> actual = testGateway.countWords("My name is Hesam");
+        Map<String, Long> expected = new HashMap<>();
+        expected.put("my", 1L);
+        expected.put("name", 1L);
+        expected.put("is", 1L);
+        expected.put("hesam", 1L);
+
+        org.junit.Assert.assertEquals(expected, actual);
+    }
+
+    @Test
+    void givenTextWithDuplicateWords_whenCallingCountWordOnGateway_thenWordCountReturnedAsMap() {
+        Map<String, Long> actual = testGateway.countWords("the dog chased the rabbit into the jungle");
+        Map<String, Long> expected = new HashMap<>();
+        expected.put("the", 3L);
+        expected.put("dog", 1L);
+        expected.put("chased", 1L);
+        expected.put("rabbit", 1L);
+        expected.put("into", 1L);
+        expected.put("jungle", 1L);
+
+        org.junit.Assert.assertEquals(expected, actual);
+    }
+
+}