教程 > Spring Boot 中文教程 > Spring Boot 教程阅读：52

Spring Boot Service 组件

服务(Service)组件是包含 @Service 注解的类文件。这些类文件用于在不同的层中编写业务逻辑，与 @RestController 类文件分开。创建服务组件类文件的逻辑如下所示

public interface ProductService {
}

实现带有@Service注解的接口的类如下

@Service
public class ProductServiceImpl implements ProductService {
}

请注意，在本教程中，我们使用 Product 服务 API 来存储、检索、更新和删除商品。我们在 @RestController 类文件本身中编写了业务逻辑。现在，我们要将业务逻辑代码从控制器移动到服务组件。

我们可以使用如下所示的代码创建一个包含添加、编辑、获取和删除方法的接口

package com.study.service;

import com.study.model.Product;

import java.util.Collection;

/**
 * @author jiyik.com
 */
public interface ProductService {
    public abstract void createProduct(Product product);
    public abstract void updateProduct(String id, Product product);
    public abstract void deleteProduct(String id);
    public abstract Collection<Product> getProducts();
}

我们将使用以下代码创建一个类，该类使用 @Service 注解实现 ProductService 接口，并编写业务逻辑来存储、检索、删除和更新商品。

package com.study.service;

import com.study.model.Product;

import java.util.Collection;
import java.util.HashMap;
import java.util.Map;

/**
 * @author jiyik.com
 */
public class ProductServiceImpl implements ProductService {

    private static Map<String, Product> productRepo = new HashMap<>();

    static {
        Product honey = new Product();

        honey.setId("1");
        honey.setName("Honey");
        productRepo.put(honey.getId(), honey);

        Product almond = new Product();
        almond.setId("2");
        almond.setName("Almond");
        productRepo.put(almond.getId(), almond);
    }

    @Override
    public void createProduct(Product product) {
        productRepo.put(product.getId(), product);
    }

    @Override
    public void updateProduct(String id, Product product) {
        productRepo.remove(id);
        product.setId(id);
        productRepo.put(id, product);
    }

    @Override
    public void deleteProduct(String id) {
        productRepo.remove(id);
    }

    @Override
    public Collection<Product> getProducts() {
        return productRepo.values();
    }
}

下面的代码显示了 Rest Controller 类文件，这里我们 @Autowired 了 ProductService 接口并调用了方法。

package com.study.controller;

import com.study.service.ProductService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.http.HttpStatus;
import org.springframework.http.ResponseEntity;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RequestBody;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.bind.annotation.RestController;

import com.study.model.Product;

@RestController
public class ProductServiceController {
    @Autowired
    ProductService productService;

    @RequestMapping(value = "/products/{id}", method = RequestMethod.PUT)
    public ResponseEntity<Object> updateProduct(@PathVariable("id") String id, @RequestBody Product product) {
        productService.updateProduct(id, product);
        return new ResponseEntity<>("商品更新成功", HttpStatus.OK);
    }

    @RequestMapping(value = "/products/{id}", method = RequestMethod.DELETE)
    public ResponseEntity<Object> delete(@PathVariable("id") String id) {
        productService.deleteProduct(id);
        return new ResponseEntity<>("商品删除成功", HttpStatus.OK);
    }

    @RequestMapping(value = "/products", method = RequestMethod.POST)
    public ResponseEntity<Object> createProduct(@RequestBody Product product) {
        productService.createProduct(product);
        return new ResponseEntity<>("商品创建成功", HttpStatus.CREATED);
    }

    @RequestMapping(value = "/products")
    public ResponseEntity<Object> getProduct() {
        return new ResponseEntity<>(productService.getProducts(), HttpStatus.OK);
    }
}

POJO 类的代码 - Product.java 如下所示

package com.study.model;

/**
 * @author jiyik.com
 */
public class Product {
    private String id;
    private String name;

    public String getId() {
        return id;
    }
    public void setId(String id) {
        this.id = id;
    }
    public String getName() {
        return name;
    }
    public void setName(String name) {
        this.name = name;
    }
}

下面给出了一个主要的 Spring Boot 应用程序

package com.study;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.context.annotation.Bean;
import org.springframework.web.client.RestTemplate;

/**
 * @author jiyik.com
 */
@SpringBootApplication
public class MyApplication {
    public static void main(String[] args) {
        SpringApplication.run(MyApplication.class, args);
    }
}

Maven build – pom.xml 的代码如下所示

<?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 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>

    <groupId>com.spring</groupId>
    <artifactId>springBootProject</artifactId>
    <version>1.0-SNAPSHOT</version>

    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.6.6</version>
    </parent>

    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>
    </dependencies>

    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
            </plugin>
        </plugins>
    </build>

</project>

Gradle Build 的代码 - build.gradle 如下所示

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.study'
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')
}

这里我们使用 IDEA 来启动服务（读者也可以使用 mvn clean install 或者 gradle clean build 生成可执行jar包）

spring boot 异常处理 IDEA启动服务