Hexagonal Architecture with Spring Boot

.gitignore

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+#Maven
+target/
+pom.xml.tag
+pom.xml.releaseBackup
+pom.xml.versionsBackup
+release.properties
+
+# Eclipse
+.project
+.classpath
+.settings/
+bin/
+
+# IntelliJ
+.idea
+*.ipr
+*.iml
+*.iws
+
+# NetBeans
+nb-configuration.xml
+
+# Visual Studio Code
+.vscode
+.factorypath
+
+# OSX
+.DS_Store
+
+# Vim
+*.swp
+*.swo
+
+# patch
+*.orig
+*.rej
+
+# Local environment
+.env

Hexagonal Architecture.postman_collection.json

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+{
+	"info": {
+		"_postman_id": "5cddaba1-07d1-4b8e-8574-da160697c2f6",
+		"name": "Hexagonal Architecture",
+		"schema": "https://schema.getpostman.com/json/collection/v2.1.0/collection.json"
+	},
+	"item": [
+		{
+			"name": "Create product",
+			"request": {
+				"method": "POST",
+				"header": [
+					{
+						"key": "Content-Type",
+						"name": "Content-Type",
+						"value": "application/json",
+						"type": "text"
+					},
+					{
+						"key": "Accept",
+						"value": "application/json",
+						"type": "text"
+					}
+				],
+				"body": {
+					"mode": "raw",
+					"raw": "{\r\n\t\"name\": \"MacBook Pro\",\r\n\t\"description\": \"14-inch MacBook Pro model\"\r\n}"
+				},
+				"url": {
+					"raw": "http://localhost:8080/v1/products",
+					"protocol": "http",
+					"host": [
+						"localhost"
+					],
+					"port": "8080",
+					"path": [
+						"v1",
+						"products"
+					]
+				}
+			},
+			"response": []
+		},
+		{
+			"name": "Find product",
+			"request": {
+				"method": "GET",
+				"header": [
+					{
+						"key": "Content-Type",
+						"name": "Content-Type",
+						"value": "application/json",
+						"type": "text"
+					},
+					{
+						"key": "Accept",
+						"value": "application/json",
+						"type": "text"
+					}
+				],
+				"url": {
+					"raw": "http://localhost:8080/v1/products/:id",
+					"protocol": "http",
+					"host": [
+						"localhost"
+					],
+					"port": "8080",
+					"path": [
+						"v1",
+						"products",
+						":id"
+					],
+					"variable": [
+						{
+							"key": "id",
+							"value": "1"
+						}
+					]
+				}
+			},
+			"response": []
+		}
+	]
+}

pom.xml

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+<?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 https://maven.apache.org/xsd/maven-4.0.0.xsd">
+    <modelVersion>4.0.0</modelVersion>
+    <parent>
+        <groupId>org.springframework.boot</groupId>
+        <artifactId>spring-boot-starter-parent</artifactId>
+        <version>2.6.3</version>
+        <relativePath/> <!-- lookup parent from repository -->
+    </parent>
+    <groupId>es.rbailen.sample</groupId>
+    <artifactId>hexagonalarchitecture</artifactId>
+    <version>0.0.1-SNAPSHOT</version>
+    <name>poc-hexagonal_architecture</name>
+    <description>Demo project for Spring Boot</description>
+    <properties>
+        <java.version>11</java.version>
+        <org.mapstruct.version>1.4.2.Final</org.mapstruct.version>
+        <lombok.version>1.18.22</lombok.version>
+    </properties>
+    <dependencies>
+        <dependency>
+            <groupId>org.springframework.boot</groupId>
+            <artifactId>spring-boot-starter-web</artifactId>
+        </dependency>
+        <dependency>
+            <groupId>org.springframework.boot</groupId>
+            <artifactId>spring-boot-devtools</artifactId>
+            <scope>runtime</scope>
+            <optional>true</optional>
+        </dependency>
+        <dependency>
+            <groupId>org.springframework.boot</groupId>
+            <artifactId>spring-boot-starter-validation</artifactId>
+        </dependency>
+        <dependency>
+            <groupId>org.projectlombok</groupId>
+            <artifactId>lombok</artifactId>
+            <optional>true</optional>
+        </dependency>
+        <dependency>
+            <groupId>com.h2database</groupId>
+            <artifactId>h2</artifactId>
+        </dependency>
+        <dependency>
+            <groupId>org.springframework.boot</groupId>
+            <artifactId>spring-boot-starter-data-jpa</artifactId>
+        </dependency>
+        <dependency>
+            <groupId>org.mapstruct</groupId>
+            <artifactId>mapstruct</artifactId>
+            <version>${org.mapstruct.version}</version>
+        </dependency>
+        <dependency>
+            <groupId>org.springframework.boot</groupId>
+            <artifactId>spring-boot-starter-test</artifactId>
+            <scope>test</scope>
+        </dependency>
+    </dependencies>
+
+    <build>
+        <plugins>
+            <plugin>
+                <groupId>org.apache.maven.plugins</groupId>
+                <artifactId>maven-compiler-plugin</artifactId>
+                <configuration>
+                    <annotationProcessorPaths>
+                        <path>
+                            <groupId>org.projectlombok</groupId>
+                            <artifactId>lombok</artifactId>
+                            <version>${lombok.version}</version>
+                        </path>
+                        <path>
+                            <groupId>org.mapstruct</groupId>
+                            <artifactId>mapstruct-processor</artifactId>
+                            <version>${org.mapstruct.version}</version>
+                        </path>
+                    </annotationProcessorPaths>
+                    <compilerArgs>
+                        <compilerArg>
+                            -Amapstruct.suppressGeneratorTimestamp=true
+                        </compilerArg>
+                        <compilerArg>
+                            -Amapstruct.suppressGeneratorVersionInfoComment=true
+                        </compilerArg>
+                        <compilerArg>
+                            -Amapstruct.defaultComponentModel=spring
+                        </compilerArg>
+                    </compilerArgs>
+                </configuration>
+            </plugin>
+        </plugins>
+    </build>
+
+</project>

src/main/java/es/rbailen/sample/hexagonalarchitecture/HexagonalArchitectureApplication.java

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+package es.rbailen.sample.hexagonalarchitecture;
+
+import org.springframework.boot.SpringApplication;
+import org.springframework.boot.autoconfigure.SpringBootApplication;
+
+@SpringBootApplication
+public class HexagonalArchitectureApplication {
+
+    public static void main(String[] args) {
+        SpringApplication.run(HexagonalArchitectureApplication.class, args);
+    }
+
+}

src/main/java/es/rbailen/sample/hexagonalarchitecture/application/ports/input/CreateProductUseCase.java

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+package es.rbailen.sample.hexagonalarchitecture.application.ports.input;
+
+import es.rbailen.sample.hexagonalarchitecture.domain.model.Product;
+
+public interface CreateProductUseCase {
+
+    Product createProduct(Product product);
+
+}

src/main/java/es/rbailen/sample/hexagonalarchitecture/application/ports/input/GetProductUseCase.java

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+package es.rbailen.sample.hexagonalarchitecture.application.ports.input;
+
+import es.rbailen.sample.hexagonalarchitecture.domain.model.Product;
+
+public interface GetProductUseCase {
+
+    Product getProductById(Long id);
+
+}

src/main/java/es/rbailen/sample/hexagonalarchitecture/application/ports/output/ProductEventPublisher.java

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+package es.rbailen.sample.hexagonalarchitecture.application.ports.output;
+
+import es.rbailen.sample.hexagonalarchitecture.domain.event.ProductCreatedEvent;
+
+public interface ProductEventPublisher {
+
+    void publishProductCreatedEvent(ProductCreatedEvent event);
+
+}

src/main/java/es/rbailen/sample/hexagonalarchitecture/application/ports/output/ProductOutputPort.java

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+package es.rbailen.sample.hexagonalarchitecture.application.ports.output;
+
+import es.rbailen.sample.hexagonalarchitecture.domain.model.Product;
+
+import java.util.Optional;
+
+public interface ProductOutputPort {
+
+    Product saveProduct(Product product);
+
+    Optional<Product> getProductById(Long id);
+
+}

src/main/java/es/rbailen/sample/hexagonalarchitecture/domain/event/ProductCreatedEvent.java

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+package es.rbailen.sample.hexagonalarchitecture.domain.event;
+
+import lombok.*;
+
+import java.time.LocalDateTime;
+
+@Builder
+@Getter
+@Setter
+@NoArgsConstructor
+@AllArgsConstructor
+public class ProductCreatedEvent {
+
+    private Long id;
+
+    private LocalDateTime date;
+
+    public ProductCreatedEvent(Long id) {
+        this.id = id;
+        this.date = LocalDateTime.now();
+    }
+
+}
+

src/main/java/es/rbailen/sample/hexagonalarchitecture/domain/exception/ProductNotFound.java

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+package es.rbailen.sample.hexagonalarchitecture.domain.exception;
+
+public class ProductNotFound extends RuntimeException {
+
+    public ProductNotFound(String message) {
+        super(message);
+    }
+
+}

src/main/java/es/rbailen/sample/hexagonalarchitecture/domain/model/Product.java

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+package es.rbailen.sample.hexagonalarchitecture.domain.model;
+
+import lombok.AllArgsConstructor;
+import lombok.Builder;
+import lombok.Getter;
+import lombok.NoArgsConstructor;
+import lombok.Setter;
+
+@Builder
+@Getter
+@Setter
+@AllArgsConstructor
+@NoArgsConstructor
+public class Product {
+
+    private Long id;
+
+    private String name;
+
+    private String description;
+
+}

src/main/java/es/rbailen/sample/hexagonalarchitecture/domain/service/ProductService.java

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+package es.rbailen.sample.hexagonalarchitecture.domain.service;
+
+import es.rbailen.sample.hexagonalarchitecture.application.ports.input.GetProductUseCase;
+import es.rbailen.sample.hexagonalarchitecture.application.ports.output.ProductEventPublisher;
+import es.rbailen.sample.hexagonalarchitecture.application.ports.output.ProductOutputPort;
+import es.rbailen.sample.hexagonalarchitecture.domain.event.ProductCreatedEvent;
+import es.rbailen.sample.hexagonalarchitecture.domain.exception.ProductNotFound;
+import es.rbailen.sample.hexagonalarchitecture.domain.model.Product;
+import es.rbailen.sample.hexagonalarchitecture.application.ports.input.CreateProductUseCase;
+import lombok.AllArgsConstructor;
+
+import java.util.Optional;
+
+@AllArgsConstructor
+public class ProductService implements CreateProductUseCase, GetProductUseCase {
+
+    private final ProductOutputPort productOutputPort;
+
+    private final ProductEventPublisher productEventPublisher;
+
+    @Override
+    public Product createProduct(Product product) {
+        product = productOutputPort.saveProduct(product);
+        productEventPublisher.publishProductCreatedEvent(new ProductCreatedEvent(product.getId()));
+        return product;
+    }
+
+    @Override
+    public Product getProductById(Long id) {
+        Optional<Product> product = productOutputPort.getProductById(id);
+
+        if(product.isEmpty()) {
+            throw new ProductNotFound("Product not found with id " + id);
+        }
+
+        return product.get();
+    }
+
+}

src/main/java/es/rbailen/sample/hexagonalarchitecture/infrastructure/adapters/config/BeanConfiguration.java

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+package es.rbailen.sample.hexagonalarchitecture.infrastructure.adapters.config;
+
+import es.rbailen.sample.hexagonalarchitecture.domain.service.ProductService;
+import es.rbailen.sample.hexagonalarchitecture.infrastructure.adapters.output.eventpublisher.ProductEventPublisherAdapter;
+import es.rbailen.sample.hexagonalarchitecture.infrastructure.adapters.output.persistence.ProductPersistenceAdapter;
+import es.rbailen.sample.hexagonalarchitecture.infrastructure.adapters.output.persistence.mapper.ProductPersistenceMapper;
+import es.rbailen.sample.hexagonalarchitecture.infrastructure.adapters.output.persistence.repository.ProductRepository;
+import org.springframework.context.ApplicationEventPublisher;
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+
+@Configuration
+public class BeanConfiguration {
+
+    @Bean
+    public ProductPersistenceAdapter productPersistenceAdapter(ProductRepository productRepository, ProductPersistenceMapper productPersistenceMapper) {
+        return new ProductPersistenceAdapter(productRepository, productPersistenceMapper);
+    }
+
+    @Bean
+    public ProductEventPublisherAdapter productEventPublisherAdapter(ApplicationEventPublisher applicationEventPublisher) {
+        return new ProductEventPublisherAdapter(applicationEventPublisher);
+    }
+
+    @Bean
+    public ProductService productService(ProductPersistenceAdapter productPersistenceAdapter, ProductEventPublisherAdapter productEventPublisherAdapter) {
+        return new ProductService(productPersistenceAdapter, productEventPublisherAdapter);
+    }
+
+}

src/main/java/es/rbailen/sample/hexagonalarchitecture/infrastructure/adapters/input/eventlistener/ProductEventListenerAdapter.java

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+package es.rbailen.sample.hexagonalarchitecture.infrastructure.adapters.input.eventlistener;
+
+import es.rbailen.sample.hexagonalarchitecture.domain.event.ProductCreatedEvent;
+import lombok.extern.slf4j.Slf4j;
+import org.springframework.context.event.EventListener;
+import org.springframework.stereotype.Component;
+
+@Component
+@Slf4j
+public class ProductEventListenerAdapter {
+
+    @EventListener
+    public void handle(ProductCreatedEvent event){
+        log.info("Product created with id " + event.getId() + " at " + event.getDate());
+    }
+
+}

src/main/java/es/rbailen/sample/hexagonalarchitecture/infrastructure/adapters/input/rest/ProductRestAdapter.java

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+package es.rbailen.sample.hexagonalarchitecture.infrastructure.adapters.input.rest;
+
+import es.rbailen.sample.hexagonalarchitecture.application.ports.input.GetProductUseCase;
+import es.rbailen.sample.hexagonalarchitecture.domain.model.Product;
+import es.rbailen.sample.hexagonalarchitecture.application.ports.input.CreateProductUseCase;
+import es.rbailen.sample.hexagonalarchitecture.infrastructure.adapters.input.rest.data.request.ProductCreateRequest;
+import es.rbailen.sample.hexagonalarchitecture.infrastructure.adapters.input.rest.data.response.ProductCreateResponse;
+import es.rbailen.sample.hexagonalarchitecture.infrastructure.adapters.input.rest.data.response.ProductQueryResponse;
+import es.rbailen.sample.hexagonalarchitecture.infrastructure.adapters.input.rest.mapper.ProductRestMapper;
+import lombok.RequiredArgsConstructor;
+import org.springframework.http.HttpStatus;
+import org.springframework.http.ResponseEntity;
+import org.springframework.web.bind.annotation.*;
+
+import javax.validation.Valid;
+
+@RestController
+@RequestMapping("/v1")
+@RequiredArgsConstructor
+public class ProductRestAdapter {
+
+    private final CreateProductUseCase createProductUseCase;
+
+    private final GetProductUseCase getProductUseCase;
+
+    private final ProductRestMapper productRestMapper;
+
+    @PostMapping(value = "/products")
+    public ResponseEntity<ProductCreateResponse> createProduct(@RequestBody @Valid ProductCreateRequest productCreateRequest){
+        // Request to domain
+        Product product = productRestMapper.toProduct(productCreateRequest);
+
+        product = createProductUseCase.createProduct(product);
+
+        // Domain to response
+        return new ResponseEntity<>(productRestMapper.toProductCreateResponse(product), HttpStatus.CREATED);
+    }
+
+    @GetMapping(value = "/products/{id}")
+    public ResponseEntity<ProductQueryResponse> getProduct(@PathVariable Long id){
+        Product product = getProductUseCase.getProductById(id);
+        return new ResponseEntity<>(productRestMapper.toProductQueryResponse(product), HttpStatus.OK);
+    }
+
+}

src/main/java/es/rbailen/sample/hexagonalarchitecture/infrastructure/adapters/input/rest/data/request/ProductCreateRequest.java

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+package es.rbailen.sample.hexagonalarchitecture.infrastructure.adapters.input.rest.data.request;
+
+import lombok.*;
+
+import javax.validation.constraints.NotEmpty;
+
+@Builder
+@Getter
+@Setter
+@AllArgsConstructor
+@NoArgsConstructor
+public class ProductCreateRequest {
+
+    @NotEmpty(message = "Name may not be empty")
+    private String name;
+
+    @NotEmpty(message = "Description may not be empty")
+    private String description;
+
+}

src/main/java/es/rbailen/sample/hexagonalarchitecture/infrastructure/adapters/input/rest/data/response/ProductCreateResponse.java

@@ -0,0 +1,18 @@
+package es.rbailen.sample.hexagonalarchitecture.infrastructure.adapters.input.rest.data.response;
+
+import lombok.*;
+
+@Builder
+@Getter
+@Setter
+@AllArgsConstructor
+@NoArgsConstructor
+public class ProductCreateResponse {
+
+    private Long id;
+
+    private String name;
+
+    private String description;
+
+}

src/main/java/es/rbailen/sample/hexagonalarchitecture/infrastructure/adapters/input/rest/data/response/ProductQueryResponse.java

@@ -0,0 +1,18 @@
+package es.rbailen.sample.hexagonalarchitecture.infrastructure.adapters.input.rest.data.response;
+
+import lombok.*;
+
+@Builder
+@Getter
+@Setter
+@AllArgsConstructor
+@NoArgsConstructor
+public class ProductQueryResponse {
+
+    private Long id;
+
+    private String name;
+
+    private String description;
+
+}

src/main/java/es/rbailen/sample/hexagonalarchitecture/infrastructure/adapters/input/rest/mapper/ProductRestMapper.java

@@ -0,0 +1,18 @@
+package es.rbailen.sample.hexagonalarchitecture.infrastructure.adapters.input.rest.mapper;
+
+import es.rbailen.sample.hexagonalarchitecture.domain.model.Product;
+import es.rbailen.sample.hexagonalarchitecture.infrastructure.adapters.input.rest.data.response.ProductQueryResponse;
+import es.rbailen.sample.hexagonalarchitecture.infrastructure.adapters.input.rest.data.request.ProductCreateRequest;
+import es.rbailen.sample.hexagonalarchitecture.infrastructure.adapters.input.rest.data.response.ProductCreateResponse;
+import org.mapstruct.Mapper;
+
+@Mapper
+public interface ProductRestMapper {
+
+    Product toProduct(ProductCreateRequest productCreateRequest);
+
+    ProductCreateResponse toProductCreateResponse(Product product);
+
+    ProductQueryResponse toProductQueryResponse(Product product);
+
+}

src/main/java/es/rbailen/sample/hexagonalarchitecture/infrastructure/adapters/output/customizedexception/CustomizedExceptionAdapter.java

@@ -0,0 +1,50 @@
+package es.rbailen.sample.hexagonalarchitecture.infrastructure.adapters.output.customizedexception;
+
+import java.time.LocalDateTime;
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.List;
+
+import es.rbailen.sample.hexagonalarchitecture.domain.exception.ProductNotFound;
+import es.rbailen.sample.hexagonalarchitecture.infrastructure.adapters.output.customizedexception.data.response.ExceptionResponse;
+import org.springframework.http.HttpHeaders;
+import org.springframework.http.HttpStatus;
+import org.springframework.http.ResponseEntity;
+import org.springframework.web.bind.MethodArgumentNotValidException;
+import org.springframework.web.bind.annotation.ControllerAdvice;
+import org.springframework.web.bind.annotation.ExceptionHandler;
+import org.springframework.web.bind.annotation.RestController;
+import org.springframework.web.context.request.WebRequest;
+import org.springframework.web.servlet.mvc.method.annotation.ResponseEntityExceptionHandler;
+
+@ControllerAdvice
+@RestController
+public class CustomizedExceptionAdapter extends ResponseEntityExceptionHandler {
+
+    @ExceptionHandler(Exception.class)
+    public final ResponseEntity<Object> handleAllExceptions(Exception ex, WebRequest request) {
+        ExceptionResponse exceptionResponse = new ExceptionResponse(LocalDateTime.now(), ex.getMessage(), Arrays.asList(request.getDescription(false)));
+
+        return new ResponseEntity(exceptionResponse, HttpStatus.INTERNAL_SERVER_ERROR);
+    }
+
+    @ExceptionHandler(ProductNotFound.class)
+    public final ResponseEntity<Object> handleUserNotFoundException(ProductNotFound ex, WebRequest request) {
+        ExceptionResponse exceptionResponse = new ExceptionResponse(LocalDateTime.now(), ex.getMessage(), Arrays.asList(request.getDescription(false)));
+
+        return new ResponseEntity(exceptionResponse, HttpStatus.NOT_FOUND);
+    }
+
+    @Override
+    protected ResponseEntity<Object> handleMethodArgumentNotValid(MethodArgumentNotValidException ex, HttpHeaders headers, HttpStatus status, WebRequest request) {
+        List<String> errors = new ArrayList<String>();
+        ex.getBindingResult().getAllErrors().stream().forEach(error -> {
+            errors.add(error.getDefaultMessage());
+        });
+
+        ExceptionResponse exceptionResponse = new ExceptionResponse(LocalDateTime.now(), "Validation Failed", errors);
+
+        return new ResponseEntity(exceptionResponse, HttpStatus.BAD_REQUEST);
+    }
+
+}

src/main/java/es/rbailen/sample/hexagonalarchitecture/infrastructure/adapters/output/customizedexception/data/response/ExceptionResponse.java

@@ -0,0 +1,22 @@
+package es.rbailen.sample.hexagonalarchitecture.infrastructure.adapters.output.customizedexception.data.response;
+
+import lombok.*;
+
+import java.time.LocalDateTime;
+import java.util.List;
+
+@Builder
+@Getter
+@Setter
+@AllArgsConstructor
+@NoArgsConstructor
+public class ExceptionResponse {
+
+    private LocalDateTime date;
+
+    private String message;
+
+    private List<String> details;
+
+}
+

src/main/java/es/rbailen/sample/hexagonalarchitecture/infrastructure/adapters/output/eventpublisher/ProductEventPublisherAdapter.java

@@ -0,0 +1,18 @@
+package es.rbailen.sample.hexagonalarchitecture.infrastructure.adapters.output.eventpublisher;
+
+import es.rbailen.sample.hexagonalarchitecture.application.ports.output.ProductEventPublisher;
+import es.rbailen.sample.hexagonalarchitecture.domain.event.ProductCreatedEvent;
+import lombok.RequiredArgsConstructor;
+import org.springframework.context.ApplicationEventPublisher;
+
+@RequiredArgsConstructor
+public class ProductEventPublisherAdapter implements ProductEventPublisher {
+
+    private final ApplicationEventPublisher applicationEventPublisher;
+
+    @Override
+    public void publishProductCreatedEvent(ProductCreatedEvent event) {
+        applicationEventPublisher.publishEvent(event);
+    }
+
+}

src/main/java/es/rbailen/sample/hexagonalarchitecture/infrastructure/adapters/output/persistence/ProductPersistenceAdapter.java

@@ -0,0 +1,38 @@
+package es.rbailen.sample.hexagonalarchitecture.infrastructure.adapters.output.persistence;
+
+import es.rbailen.sample.hexagonalarchitecture.application.ports.output.ProductOutputPort;
+import es.rbailen.sample.hexagonalarchitecture.domain.model.Product;
+import es.rbailen.sample.hexagonalarchitecture.infrastructure.adapters.output.persistence.entity.ProductEntity;
+import es.rbailen.sample.hexagonalarchitecture.infrastructure.adapters.output.persistence.mapper.ProductPersistenceMapper;
+import es.rbailen.sample.hexagonalarchitecture.infrastructure.adapters.output.persistence.repository.ProductRepository;
+import lombok.RequiredArgsConstructor;
+
+import java.util.Optional;
+
+@RequiredArgsConstructor
+public class ProductPersistenceAdapter implements ProductOutputPort {
+
+    private final ProductRepository productRepository;
+
+    private final ProductPersistenceMapper productPersistenceMapper;
+
+    @Override
+    public Product saveProduct(Product product) {
+        ProductEntity productEntity = productPersistenceMapper.toProductEntity(product);
+        productEntity = productRepository.save(productEntity);
+        return productPersistenceMapper.toProduct(productEntity);
+    }
+
+    @Override
+    public Optional<Product> getProductById(Long id) {
+        Optional<ProductEntity> productEntity = productRepository.findById(id);
+
+        if(productEntity.isEmpty()) {
+            return Optional.empty();
+        }
+
+        Product product = productPersistenceMapper.toProduct(productEntity.get());
+        return Optional.of(product);
+    }
+
+}

src/main/java/es/rbailen/sample/hexagonalarchitecture/infrastructure/adapters/output/persistence/entity/ProductEntity.java

@@ -0,0 +1,26 @@
+package es.rbailen.sample.hexagonalarchitecture.infrastructure.adapters.output.persistence.entity;
+
+import lombok.*;
+
+import javax.persistence.Entity;
+import javax.persistence.GeneratedValue;
+import javax.persistence.GenerationType;
+import javax.persistence.Id;
+
+@Entity
+@Getter
+@Setter
+@AllArgsConstructor
+@NoArgsConstructor
+@Builder
+public class ProductEntity {
+
+    @Id
+    @GeneratedValue(strategy = GenerationType.IDENTITY)
+    private Long id;
+
+    private String name;
+
+    private String description;
+
+}

src/main/java/es/rbailen/sample/hexagonalarchitecture/infrastructure/adapters/output/persistence/mapper/ProductPersistenceMapper.java

@@ -0,0 +1,14 @@
+package es.rbailen.sample.hexagonalarchitecture.infrastructure.adapters.output.persistence.mapper;
+
+import es.rbailen.sample.hexagonalarchitecture.domain.model.Product;
+import es.rbailen.sample.hexagonalarchitecture.infrastructure.adapters.output.persistence.entity.ProductEntity;
+import org.mapstruct.Mapper;
+
+@Mapper
+public interface ProductPersistenceMapper {
+
+    ProductEntity toProductEntity(Product product);
+
+    Product toProduct(ProductEntity productEntity);
+
+}

src/main/java/es/rbailen/sample/hexagonalarchitecture/infrastructure/adapters/output/persistence/repository/ProductRepository.java

@@ -0,0 +1,10 @@
+package es.rbailen.sample.hexagonalarchitecture.infrastructure.adapters.output.persistence.repository;
+
+import es.rbailen.sample.hexagonalarchitecture.infrastructure.adapters.output.persistence.entity.ProductEntity;
+import org.springframework.data.jpa.repository.JpaRepository;
+import org.springframework.stereotype.Repository;
+
+@Repository
+public interface ProductRepository extends JpaRepository<ProductEntity, Long> {
+
+}

src/main/resources/application.yml

@@ -0,0 +1,17 @@
+server:
+  port: 8080
+
+logging:
+  level:
+    es.rbailen.sample.hexagonalarchitecture: info
+
+spring:
+  jpa:
+    show-sql: false
+  h2:
+    console:
+      enabled: true
+  datasource:
+    url: jdbc:h2:mem:testdb;DB_CLOSE_DELAY=- 1;DB_CLOSE_ON_EXIT=FALSE
+    username: test
+    password: test

src/test/java/es/rbailen/sample/hexagonalarchitecture/HexagonalArchitectureApplicationTests.java

@@ -0,0 +1,13 @@
+package es.rbailen.sample.hexagonalarchitecture;
+
+import org.junit.jupiter.api.Test;
+import org.springframework.boot.test.context.SpringBootTest;
+
+@SpringBootTest
+class HexagonalArchitectureApplicationTests {
+
+    @Test
+    void contextLoads() {
+    }
+
+}