add order command query for test in project and add consumer kfka for test event driven read model design pattern

dont forget change implementation of kafka consumer to list of values

src/main/java/com/example/mmad/testapp/Listner/UserEventListener.java

@@ -14,14 +14,15 @@ public class UserEventListener {
         this.userSnapshotRepository = userSnapshotRepository;
     }
 
-    @KafkaListener(topics = "user-commanded", groupId = "")
+    @KafkaListener(topics = "user-created", containerFactory = "kafkaListenerContainerFactory", groupId = "test")
     public void updatedUserSnapshot(UserCreatedEvent user) {
         UserEntity userSnapshot = new UserEntity();
         //Todo write an mapper
-        userSnapshot.setId(userSnapshot.getId());
+        userSnapshot.setId(user.getUserId());
         userSnapshot.setUserName(user.getUsername());
         userSnapshot.setEmail(user.getEmail());
-        userSnapshotRepository.save(userSnapshot);
+        System.out.println("snapshot is updated" + user.getUserId());
+//        userSnapshotRepository.save(userSnapshot);
     }
 
 }

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

@@ -0,0 +1,13 @@
+package com.example.mmad.testapp.command;
+
+import lombok.Getter;
+import lombok.Setter;
+
+@Getter
+@Setter
+public class CreateOrderCommand {
+
+    private Long orderId;
+    private String orderName;
+    private String description;
+}

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

@@ -1,13 +0,0 @@
-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/OrderCommandHandler.java

@@ -0,0 +1,33 @@
+package com.example.mmad.testapp.command;
+
+import com.example.mmad.testapp.entity.OrderEntity;
+import com.example.mmad.testapp.event.OrderCreatedEvent;
+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 OrderCommandHandler {
+    @Autowired
+    private ApplicationEventPublisher applicationEventPublisher;
+    private final UserRepository userRepository;
+
+    public OrderCommandHandler(UserRepository userRepository) {
+        this.userRepository = userRepository;
+    }
+
+    public void createUser(CreateOrderCommand createUserCommand) {
+        OrderEntity orderEntity = new OrderEntity();
+        orderEntity.setId(createUserCommand.getOrderId());
+        orderEntity.setOrderName(createUserCommand.getOrderName());
+        orderEntity.setDescription(createUserCommand.getDescription());
+//        userRepository.save(orderEntity);
+        OrderCreatedEvent event = new OrderCreatedEvent(
+                orderEntity.getId(),
+                orderEntity.getOrderName(),
+                orderEntity.getDescription()
+        );
+        applicationEventPublisher.publishEvent(event);
+    }
+}

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

@@ -1,33 +0,0 @@
-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

@@ -1,7 +1,7 @@
 package com.example.mmad.testapp.controller;
 
-import com.example.mmad.testapp.command.CreateUserCommand;
-import com.example.mmad.testapp.command.UserCommandHandler;
+import com.example.mmad.testapp.command.CreateOrderCommand;
+import com.example.mmad.testapp.command.OrderCommandHandler;
 import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.http.HttpStatus;
 import org.springframework.http.ResponseEntity;
@@ -13,10 +13,10 @@ import javax.validation.Valid;
 @RequestMapping("/user")
 public class UserController {
 
-    private UserCommandHandler userCommandHandler;
+    private OrderCommandHandler userCommandHandler;
 
     @Autowired
-    public void setPersonService(UserCommandHandler userCommandHandler) {
+    public void setPersonService(OrderCommandHandler userCommandHandler) {
         this.userCommandHandler = userCommandHandler;
     }
 
@@ -28,7 +28,7 @@ public class UserController {
 
     @CrossOrigin(origins = "http://localhost:3001")
     @PostMapping("/create")
-    public ResponseEntity<?> create(@Valid @RequestBody CreateUserCommand userCommand) {
+    public ResponseEntity<?> create(@Valid @RequestBody CreateOrderCommand userCommand) {
         userCommandHandler.createUser(userCommand);
         return ResponseEntity.ok(200);
     }

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

@@ -0,0 +1,25 @@
+package com.example.mmad.testapp.entity;
+
+import jakarta.persistence.*;
+import lombok.*;
+
+import static jakarta.persistence.GenerationType.SEQUENCE;
+
+@Entity
+@Getter
+@Setter
+@Table(schema = "testapp", name = "order")
+@Builder
+@AllArgsConstructor
+@NoArgsConstructor
+public class OrderEntity {
+
+    @Id
+    @SequenceGenerator(name = "seqTest", sequenceName = "testapp.order_seq", allocationSize = 1)
+    @GeneratedValue(strategy = SEQUENCE, generator = "seqTest")
+    private Long id;
+    @Column(name = "order_name")
+    private String orderName;
+    @Column(name = "description")
+    private String description;
+}

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

@@ -0,0 +1,25 @@
+package com.example.mmad.testapp.event;
+
+public class OrderCreatedEvent {
+    private final Long orderId;
+    private final String orderName;
+    private final String description;
+
+    public OrderCreatedEvent(Long orderId, String orderName, String description) {
+        this.orderId = orderId;
+        this.orderName = orderName;
+        this.description = description;
+    }
+
+    public Long getOrderId() {
+        return orderId;
+    }
+
+    public String getOrderName() {
+        return orderName;
+    }
+
+    public String getDescription() {
+        return description;
+    }
+}

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

@@ -1,25 +1,14 @@
 package com.example.mmad.testapp.event;
 
-public class UserCreatedEvent {
-    private final Long userId;
-    private final String username;
-    private final String email;
+import lombok.Getter;
+import lombok.Setter;
 
-    public UserCreatedEvent(Long userId, String username, String email) {
-        this.userId = userId;
-        this.username = username;
-        this.email = email;
-    }
+import java.io.Serializable;
 
-    public Long getUserId() {
-        return userId;
-    }
-
-    public String getUsername() {
-        return username;
-    }
-
-    public String getEmail() {
-        return email;
-    }
+@Getter
+@Setter
+public class UserCreatedEvent implements Serializable {
+    private Long userId;
+    private String username;
+    private String email;
 }

src/main/java/com/example/mmad/testapp/kafkaConsumerConfig/KafkaConsumerConfig.java

@@ -1,8 +1,9 @@
 package com.example.mmad.testapp.kafkaConsumerConfig;
 
-import com.fasterxml.jackson.core.type.TypeReference;
+import com.example.mmad.testapp.event.UserCreatedEvent;
 import org.apache.kafka.clients.consumer.ConsumerConfig;
 import org.apache.kafka.common.serialization.StringDeserializer;
+import org.springframework.beans.factory.annotation.Value;
 import org.springframework.boot.context.properties.ConfigurationProperties;
 import org.springframework.context.annotation.Bean;
 import org.springframework.context.annotation.Configuration;
@@ -12,7 +13,6 @@ import org.springframework.kafka.core.DefaultKafkaConsumerFactory;
 import org.springframework.kafka.support.serializer.JsonDeserializer;
 
 import java.util.HashMap;
-import java.util.List;
 import java.util.Map;
 
 @EnableKafka
@@ -20,32 +20,29 @@ import java.util.Map;
 @ConfigurationProperties(prefix = "spring.kafka.consumer")
 public class KafkaConsumerConfig {
 
+    @Value("${spring.kafka.consumer.bootstrap-servers}")
     private String bootstrapServers;
 
+    @Value("${spring.kafka.consumer.group-id}")
     private String groupId;
 
-
     @Bean
-    public DefaultKafkaConsumerFactory<String, List<?>> consumerFactory() {
-        JsonDeserializer<List<?>> deserializer =
-                new JsonDeserializer<>(new TypeReference<List<?>>() {
-                });
-        deserializer.setRemoveTypeHeaders(false);
+    public DefaultKafkaConsumerFactory<String, UserCreatedEvent> consumerFactory() {
+        JsonDeserializer<UserCreatedEvent> deserializer = new JsonDeserializer<>(UserCreatedEvent.class);
         deserializer.addTrustedPackages("*");
-        deserializer.setUseTypeMapperForKey(true);
 
         Map<String, Object> config = new HashMap<>();
         config.put(ConsumerConfig.BOOTSTRAP_SERVERS_CONFIG, bootstrapServers);
         config.put(ConsumerConfig.GROUP_ID_CONFIG, groupId);
         config.put(ConsumerConfig.KEY_DESERIALIZER_CLASS_CONFIG, StringDeserializer.class);
-        config.put(ConsumerConfig.VALUE_DESERIALIZER_CLASS_CONFIG, deserializer);
+        config.put(ConsumerConfig.VALUE_DESERIALIZER_CLASS_CONFIG, JsonDeserializer.class);
 
         return new DefaultKafkaConsumerFactory<>(config, new StringDeserializer(), deserializer);
     }
 
     @Bean
-    public ConcurrentKafkaListenerContainerFactory<String, List<?>> kafkaListenerContainerFactory() {
-        ConcurrentKafkaListenerContainerFactory<String, List<?>> factory = new ConcurrentKafkaListenerContainerFactory<>();
+    public ConcurrentKafkaListenerContainerFactory<String, UserCreatedEvent> kafkaListenerContainerFactory() {
+        ConcurrentKafkaListenerContainerFactory<String, UserCreatedEvent> factory = new ConcurrentKafkaListenerContainerFactory<>();
         factory.setConsumerFactory(consumerFactory());
         return factory;
     }

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

@@ -1,6 +1,6 @@
 package com.example.mmad.testapp.query;
 
-import com.example.mmad.testapp.event.UserCreatedEvent;
+import com.example.mmad.testapp.event.OrderCreatedEvent;
 import org.springframework.context.event.EventListener;
 import org.springframework.scheduling.annotation.Async;
 import org.springframework.stereotype.Component;
@@ -9,7 +9,7 @@ import org.springframework.stereotype.Component;
 public class UserQueryHandler {
     @Async("taskExecutor")
     @EventListener
-    public void handelUserCreated(UserCreatedEvent event) {
-        System.out.println("Received user created event" + event.getUserId());
+    public void handelUserCreated(OrderCreatedEvent event) {
+        System.out.println("Received user created event" + event.getOrderId());
     }
 }

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

@@ -1,10 +1,10 @@
 package com.example.mmad.testapp.repository;
 
-import com.example.mmad.testapp.entity.UserEntity;
+import com.example.mmad.testapp.entity.OrderEntity;
 import org.springframework.data.jpa.repository.JpaRepository;
 import org.springframework.stereotype.Repository;
 
 @Repository
-public interface UserRepository extends JpaRepository<UserEntity, Long> {
+public interface UserRepository extends JpaRepository<OrderEntity, Long> {
 
 }

src/main/resources/application.properties

@@ -1,4 +1,4 @@
-spring.application.name=service-a
+spring.application.name=service-b
 eureka.client.service-url.defaultZone=http://localhost:8761/eureka
 spring.config.import=configserver:http://localhost:8888/
 eureka.client.register-with-eureka=true