Spring Boot 教程：服务组件

【注】本文译自： https://www.tutorialspoint.com/spring_boot/spring_boot_service_components.htm

服务组件是包含 @Service 注解的类文件。这些类文件可用在与 @RestController 类文件所不同的层来编写业务逻辑。创建服务组件类文件如下所示：

1 public interface ProductService {
2 }

以 @Service 注解实现接口的类如下所示：

1 @Service
2 public class ProductServiceImpl implements ProductService {
3 }

回顾以前的教程中，我们使用产品服务 API(s) 来存储、获取、更新和删除产品。我们在 @RestController 类文件自身中编写业务逻辑。现在我们要把业务逻辑代码从控制器移到服务组件。

你可以创建一个接口，包含增加、编辑、获取和删除方法，示例代码如下：

 1 package com.tutorialspoint.demo.service;
 2  
 3 import java.util.Collection;
 4 import com.tutorialspoint.demo.model.Product;
 5  
 6 public interface ProductService {
 7    public abstract void createProduct(Product product);
 8    public abstract void updateProduct(String id, Product product);
 9    public abstract void deleteProduct(String id);
10    public abstract Collection<Product> getProducts();
11 }

以下代码将让你创建一个以 @Service 注解来实现 ProductService 接口的类，用以编写存储、获取、删除和更新产品。

 1 package com.tutorialspoint.demo.service;
 2  
 3 import java.util.Collection;
 4 import java.util.HashMap;
 5 import java.util.Map;
 6 import org.springframework.stereotype.Service;
 7 import com.tutorialspoint.demo.model.Product;
 8  
 9 @Service
10 public class ProductServiceImpl implements ProductService {
11    private static Map<String, Product> productRepo = new HashMap<>();
12    static {
13       Product honey = new Product();
14       honey.setId("1");
15       honey.setName("Honey");
16       productRepo.put(honey.getId(), honey);
17  
18       Product almond = new Product();
19       almond.setId("2");
20       almond.setName("Almond");
21       productRepo.put(almond.getId(), almond);
22    }
23    @Override
24    public void createProduct(Product product) {
25       productRepo.put(product.getId(), product);
26    }
27    @Override
28    public void updateProduct(String id, Product product) {
29       productRepo.remove(id);
30       product.setId(id);
31       productRepo.put(id, product);
32    }
33    @Override
34    public void deleteProduct(String id) {
35       productRepo.remove(id);
36  
37    }
38    @Override
39    public Collection<Product> getProducts() {
40       return productRepo.values();
41    }
42 }

以里的代码展示了 Rest Controller 类文件，我们用 @Autowired 来自动注入 ProductService 接口并调用其方法。

 1 package com.tutorialspoint.demo.controller;
 2  
 3 import org.springframework.beans.factory.annotation.Autowired;
 4 import org.springframework.http.HttpStatus;
 5 import org.springframework.http.ResponseEntity;
 6 import org.springframework.web.bind.annotation.PathVariable;
 7 import org.springframework.web.bind.annotation.RequestBody;
 8 import org.springframework.web.bind.annotation.RequestMapping;
 9 import org.springframework.web.bind.annotation.RequestMethod;
10 import org.springframework.web.bind.annotation.RestController;
11  
12 import com.tutorialspoint.demo.model.Product;
13 import com.tutorialspoint.demo.service.ProductService;
14  
15 @RestController
16 public class ProductServiceController {
17    @Autowired
18    ProductService productService;
19  
20    @RequestMapping(value = "/products")
21    public ResponseEntity<Object> getProduct() {
22       return new ResponseEntity<>(productService.getProducts(), HttpStatus.OK);
23    }
24    @RequestMapping(value = "/products/{id}", method = RequestMethod.PUT)
25    public ResponseEntity<Object> 
26       updateProduct(@PathVariable("id") String id, @RequestBody Product product) {
27       
28       productService.updateProduct(id, product);
29       return new ResponseEntity<>("Product is updated successsfully", HttpStatus.OK);
30    }
31    @RequestMapping(value = "/products/{id}", method = RequestMethod.DELETE)
32    public ResponseEntity<Object> delete(@PathVariable("id") String id) {
33       productService.deleteProduct(id);
34       return new ResponseEntity<>("Product is deleted successsfully", HttpStatus.OK);
35    }
36    @RequestMapping(value = "/products", method = RequestMethod.POST)
37    public ResponseEntity<Object> createProduct(@RequestBody Product product) {
38       productService.createProduct(product);
39       return new ResponseEntity<>("Product is created successfully", HttpStatus.CREATED);
40    }
41 }

POJO class – Product.java 代码在此：

 1 package com.tutorialspoint.demo.model;
 2  
 3 public class Product {
 4    private String id;
 5    private String name;
 6  
 7    public String getId() {
 8       return id;
 9    }
10    public void setId(String id) {
11       this.id = id;
12    }
13    public String getName() {
14       return name;
15    }
16    public void setName(String name) {
17       this.name = name;
18    }
19 }

主 Spring Boot 应用如下：

 1 package com.tutorialspoint.demo;
 2  
 3 import org.springframework.boot.SpringApplication;
 4 import org.springframework.boot.autoconfigure.SpringBootApplication;
 5  
 6 @SpringBootApplication
 7 public class DemoApplication {
 8    public static void main(String[] args) {
 9       SpringApplication.run(DemoApplication.class, args);
10    }
11 }

Maven build – pom.xml 代码如下所示：

 1 <?xml version = "1.0" encoding = "UTF-8"?>
 2 <project xmlns = "http://maven.apache.org/POM/4.0.0" 
 3    xmlns:xsi = "http://www.w3.org/2001/XMLSchema-instance"
 4    xsi:schemaLocation = "http://maven.apache.org/POM/4.0.0 
 5    http://maven.apache.org/xsd/maven-4.0.0.xsd">
 6    
 7    <modelVersion>4.0.0</modelVersion>
 8    <groupId>com.tutorialspoint</groupId>
 9    <artifactId>demo</artifactId>
10    <version>0.0.1-SNAPSHOT</version>
11    <packaging>jar</packaging>
12    <name>demo</name>
13    <description>Demo project for Spring Boot</description>
14  
15    <parent>
16       <groupId>org.springframework.boot</groupId>
17       <artifactId>spring-boot-starter-parent</artifactId>
18       <version>1.5.8.RELEASE</version>
19       <relativePath/> 
20    </parent>
21  
22    <properties>
23       <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
24       <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
25       <java.version>1.8</java.version>
26    </properties>
27  
28    <dependencies>
29       <dependency>
30          <groupId>org.springframework.boot</groupId>
31          <artifactId>spring-boot-starter-web</artifactId>
32       </dependency>
33  
34       <dependency>
35          <groupId>org.springframework.boot</groupId>
36          <artifactId>spring-boot-starter-test</artifactId>
37          <scope>test</scope>
38       </dependency>
39    </dependencies>
40  
41    <build>
42       <plugins>
43          <plugin>
44             <groupId>org.springframework.boot</groupId>
45             <artifactId>spring-boot-maven-plugin</artifactId>
46          </plugin>
47       </plugins>
48    </build>
49  
50 </project>

Gradle Build – build.gradle 代码如下：

buildscript {
   ext {
      springBootVersion = '1.5.8.RELEASE'
   }
   repositories {
      mavenCentral()
   }
   dependencies {
      classpath("org.springframework.boot:spring-boot-gradle-plugin:${springBootVersion}")
   }
}
 
apply plugin: 'java'
apply plugin: 'eclipse'
apply plugin: 'org.springframework.boot'
 
group = 'com.tutorialspoint'
version = '0.0.1-SNAPSHOT'
sourceCompatibility = 1.8
 
repositories {
   mavenCentral()
}
dependencies {
   compile('org.springframework.boot:spring-boot-starter-web')
   testCompile('org.springframework.boot:spring-boot-starter-test')
}