add new package

patterns-modules/design-patterns-architectural/src/main/java/com/baeldung/dtopattern/Main.java

@@ -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);
+    }
+}
+

patterns-modules/design-patterns-architectural/src/main/java/com/baeldung/dtopattern/api/Mapper.java

@@ -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<>());
+    }
+}

patterns-modules/design-patterns-architectural/src/main/java/com/baeldung/dtopattern/api/UserController.java

@@ -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());
+    }
+
+}

patterns-modules/design-patterns-architectural/src/main/java/com/baeldung/dtopattern/api/UserCreationDTO.java

@@ -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;
+    }
+}

patterns-modules/design-patterns-architectural/src/main/java/com/baeldung/dtopattern/api/UserDTO.java

@@ -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;
+    }
+
+}

patterns-modules/design-patterns-architectural/src/main/java/com/baeldung/dtopattern/api/UserIdDTO.java

@@ -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;
+    }
+}

patterns-modules/design-patterns-architectural/src/main/java/com/baeldung/dtopattern/domain/InMemoryRepository.java

@@ -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();
+    }
+}

patterns-modules/design-patterns-architectural/src/main/java/com/baeldung/dtopattern/domain/Role.java

@@ -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);
+    }
+}

patterns-modules/design-patterns-architectural/src/main/java/com/baeldung/dtopattern/domain/RoleRepository.java

@@ -0,0 +1,7 @@
+package com.baeldung.dtopattern.domain;
+
+public interface RoleRepository {
+    Role getRoleById(String id);
+    Role getRoleByName(String name);
+    void save(Role role);
+}

patterns-modules/design-patterns-architectural/src/main/java/com/baeldung/dtopattern/domain/RoleService.java

@@ -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);
+    }
+
+}

patterns-modules/design-patterns-architectural/src/main/java/com/baeldung/dtopattern/domain/User.java

@@ -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 "";
+        }
+    }
+}

patterns-modules/design-patterns-architectural/src/main/java/com/baeldung/dtopattern/domain/UserRepository.java

@@ -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();
+}

patterns-modules/design-patterns-architectural/src/main/java/com/baeldung/dtopattern/domain/UserService.java

@@ -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);
+    }
+}

patterns-modules/design-patterns-architectural/src/main/java/com/baeldung/mvc_mvp/mvc/MvcMainClass.java

@@ -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;
+    }
+}

patterns-modules/design-patterns-architectural/src/main/java/com/baeldung/mvc_mvp/mvc/Product.java

@@ -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);
+    }
+    
+}

patterns-modules/design-patterns-architectural/src/main/java/com/baeldung/mvc_mvp/mvc/ProductController.java

@@ -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);
+    }
+    
+}

patterns-modules/design-patterns-architectural/src/main/java/com/baeldung/mvc_mvp/mvc/ProductView.java

@@ -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);
+    }
+}

patterns-modules/design-patterns-architectural/src/main/java/com/baeldung/mvc_mvp/mvp/MvpMainClass.java

@@ -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;
+    }
+}

patterns-modules/design-patterns-architectural/src/main/java/com/baeldung/mvc_mvp/mvp/Product.java

@@ -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;
+    }
+    
+}

patterns-modules/design-patterns-architectural/src/main/java/com/baeldung/mvc_mvp/mvp/ProductPresenter.java

@@ -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());
+    }
+    
+}

patterns-modules/design-patterns-architectural/src/main/java/com/baeldung/mvc_mvp/mvp/ProductView.java

@@ -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);
+    }
+}

patterns-modules/design-patterns-architectural/src/main/java/com/baeldung/repositoryvsdaopattern/Tweet.java

@@ -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;
+    }
+
+}

patterns-modules/design-patterns-architectural/src/main/java/com/baeldung/repositoryvsdaopattern/TweetDao.java

@@ -0,0 +1,9 @@
+package com.baeldung.repositoryvsdaopattern;
+
+import java.util.List;
+
+public interface TweetDao {
+
+    List<Tweet> fetchTweets(String email);
+    
+}

patterns-modules/design-patterns-architectural/src/main/java/com/baeldung/repositoryvsdaopattern/TweetDaoImpl.java

@@ -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;
+    }
+
+}

patterns-modules/design-patterns-architectural/src/main/java/com/baeldung/repositoryvsdaopattern/User.java

@@ -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;
+    }
+    
+}

patterns-modules/design-patterns-architectural/src/main/java/com/baeldung/repositoryvsdaopattern/UserDao.java

@@ -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);
+
+}

patterns-modules/design-patterns-architectural/src/main/java/com/baeldung/repositoryvsdaopattern/UserDaoImpl.java

@@ -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) {
+        
+    }
+
+}

patterns-modules/design-patterns-architectural/src/main/java/com/baeldung/repositoryvsdaopattern/UserRepository.java

@@ -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);
+    
+}

patterns-modules/design-patterns-architectural/src/main/java/com/baeldung/repositoryvsdaopattern/UserRepositoryImpl.java

@@ -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;
+    }
+
+}

patterns-modules/design-patterns-architectural/src/main/java/com/baeldung/repositoryvsdaopattern/UserSocialMedia.java

@@ -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;
+    }
+
+}