implement base of cqrs pattern with applicationEventPublisher for command and query inside one microservice

structure of package

src/main/java/com/example/mmad/testapp/command/CreateUserCommand.java

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+package com.example.mmad.testapp.command;
+
+import lombok.Getter;
+import lombok.Setter;
+
+@Getter
+@Setter
+public class CreateUserCommand {
+
+    private Long userId;
+    private String userName;
+    private String email;
+}

src/main/java/com/example/mmad/testapp/command/UserCommandHandler.java

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+package com.example.mmad.testapp.command;
+
+import com.example.mmad.testapp.entity.UserEntity;
+import com.example.mmad.testapp.event.UserCreatedEvent;
+import com.example.mmad.testapp.repository.UserRepository;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.context.ApplicationEventPublisher;
+import org.springframework.stereotype.Service;
+
+@Service
+public class UserCommandHandler {
+    @Autowired
+    private ApplicationEventPublisher applicationEventPublisher;
+    private final UserRepository userRepository;
+
+    public UserCommandHandler(UserRepository userRepository) {
+        this.userRepository = userRepository;
+    }
+
+    public void createUser(CreateUserCommand createUserCommand) {
+        UserEntity userEntity = new UserEntity();
+        userEntity.setId(createUserCommand.getUserId());
+        userEntity.setUserName(createUserCommand.getUserName());
+        userEntity.setEmail(createUserCommand.getEmail());
+//        userRepository.save(userEntity);
+        UserCreatedEvent event = new UserCreatedEvent(
+                userEntity.getId(),
+                userEntity.getUserName(),
+                userEntity.getEmail()
+        );
+        applicationEventPublisher.publishEvent(event);
+    }
+}

src/main/java/com/example/mmad/testapp/controller/UserController.java

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+package com.example.mmad.testapp.controller;
+
+import com.example.mmad.testapp.command.CreateUserCommand;
+import com.example.mmad.testapp.command.UserCommandHandler;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.http.HttpStatus;
+import org.springframework.http.ResponseEntity;
+import org.springframework.web.bind.annotation.*;
+
+import javax.validation.Valid;
+
+@RestController
+@RequestMapping("/user")
+public class UserController {
+
+    private UserCommandHandler userCommandHandler;
+
+    @Autowired
+    public void setPersonService(UserCommandHandler userCommandHandler) {
+        this.userCommandHandler = userCommandHandler;
+    }
+
+    @PostMapping("/list")
+    @ResponseStatus(HttpStatus.OK)
+    public String listPosts() {
+        return "userHandler";
+    }
+
+    @CrossOrigin(origins = "http://localhost:3001")
+    @PostMapping("/create")
+    public ResponseEntity<?> create(@Valid @RequestBody CreateUserCommand userCommand) {
+        userCommandHandler.createUser(userCommand);
+        return ResponseEntity.ok(200);
+    }
+}

src/main/java/com/example/mmad/testapp/entity/UserEntity.java

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+package com.example.mmad.testapp.entity;
+
+import jakarta.persistence.*;
+import lombok.*;
+
+import static jakarta.persistence.GenerationType.SEQUENCE;
+
+@Entity
+@Getter
+@Setter
+@Table(schema = "testapp", name = "user")
+@Builder
+@AllArgsConstructor
+@NoArgsConstructor
+public class UserEntity {
+
+    @Id
+    @SequenceGenerator(name = "seqTest", sequenceName = "testapp.person_seq", allocationSize = 1)
+    @GeneratedValue(strategy = SEQUENCE, generator = "seqTest")
+    private Long id;
+    @Column(name = "user_name")
+    private String userName;
+    @Column(name = "email")
+    private String email;
+}

src/main/java/com/example/mmad/testapp/event/UserCreatedEvent.java

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+package com.example.mmad.testapp.event;
+
+public class UserCreatedEvent {
+    private final Long userId;
+    private final String username;
+    private final String email;
+
+    public UserCreatedEvent(Long userId, String username, String email) {
+        this.userId = userId;
+        this.username = username;
+        this.email = email;
+    }
+
+    public Long getUserId() {
+        return userId;
+    }
+
+    public String getUsername() {
+        return username;
+    }
+
+    public String getEmail() {
+        return email;
+    }
+}

src/main/java/com/example/mmad/testapp/query/UserQueryHandler.java

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+package com.example.mmad.testapp.query;
+
+import com.example.mmad.testapp.event.UserCreatedEvent;
+import org.springframework.context.event.EventListener;
+import org.springframework.stereotype.Component;
+
+@Component
+public class UserQueryHandler {
+    @EventListener
+    public void handelUserCreated(UserCreatedEvent event) {
+        System.out.println("Received user created event" + event.getUserId());
+    }
+}

src/main/java/com/example/mmad/testapp/query/UserReadModel.java

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+package com.example.mmad.testapp.query;
+
+public class UserReadModel {
+}

src/main/java/com/example/mmad/testapp/repository/UserReadRepository.java

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+package com.example.mmad.testapp.repository;
+
+import com.example.mmad.testapp.entity.PersonEntity;
+import org.springframework.data.jpa.repository.JpaRepository;
+import org.springframework.stereotype.Repository;
+
+@Repository
+public interface UserReadRepository extends JpaRepository<PersonEntity, Long> {
+}

src/main/java/com/example/mmad/testapp/repository/UserRepository.java

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+package com.example.mmad.testapp.repository;
+
+import com.example.mmad.testapp.entity.UserEntity;
+import org.springframework.data.jpa.repository.JpaRepository;
+import org.springframework.stereotype.Repository;
+
+@Repository
+public interface UserRepository extends JpaRepository<UserEntity, Long> {
+
+}