一 点睛
Spring Cloud Feign提供了继承特性,可以进一步减少编码量。
二 编写hello-service-api
1 创建一个基础的Maven工程,命名为hello-service-api
2 编写pom.xml
<?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/4.0.0http://maven.apache.org/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>
<groupId>com.didispace</groupId>
<artifactId>hello-service-api</artifactId>
<version>0.0.1-SNAPSHOT</version>
<packaging>jar</packaging>
<name>hello-service-api</name>
<parent>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-parent</artifactId>
<version>1.3.7.RELEASE</version>
<relativePath/> <!-- lookup parent from repository -->
</parent>
<properties>
<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
<project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
<java.version>1.8</java.version>
</properties>
<dependencies>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency>
</dependencies>
</project>
3 编写实体类User
package com.didispace.dto;
/**
* Created by Administrator on 2016/9/16.
*/
public class User {
private String name;
private Integer age;
public User() {
}
public User(String name, Integer age) {
this.name = name;
this.age = age;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public Integer getAge() {
return age;
}
public void setAge(Integer age) {
this.age = age;
}
@Override
public String toString() {
return "name=" + name + ", age=" +age;
}
}
4 编写HelloService接口
package com.didispace.service;
import com.didispace.dto.User;
import org.springframework.web.bind.annotation.*;
@RequestMapping("/refactor")
public interface HelloService {
@RequestMapping(value = "/hello4", method = RequestMethod.GET)
String hello(@RequestParam("name") String name) ;
@RequestMapping(value = "/hello5", method = RequestMethod.GET)
User hello(@RequestHeader("name") String name, @RequestHeader("age") Integer age);
@RequestMapping(value = "/hello6", method = RequestMethod.POST)
String hello(@RequestBody User user);
}
三 编写hello-service
1 给pom.xml增加依赖
<dependency>
<groupId>com.didispace</groupId>
<artifactId>hello-service-api</artifactId>
<version>0.0.1-SNAPSHOT</version>
</dependency>
2 创建RefactorHelloController接口,实现hello-service-api中定义的接口HelloService
HelloServicepackage com.didispace.web;
import com.didispace.dto.User;
import com.didispace.service.HelloService;
import org.springframework.web.bind.annotation.*;
@RestController
public class RefactorHelloController implements HelloService {
@Override
public String hello(@RequestParam("name") String name) {
return "Hello " + name;
}
@Override
public User hello(@RequestHeader("name") String name, @RequestHeader("age") Integer age) {
return new User(name, age);
}
@Override
public String hello(@RequestBody User user) {
return "Hello "+ user.getName() + ", " + user.getAge();
}
}
通过实现的方式,在Contrlooer中不再包含以往会定义的请求映射注解@RequestMapping,在重写的时候会自动将注解带过来。在这个类中,除了实现接口的逻辑之外,只需要增加@RestController注解使该来成为一个REST接口类就可以了。
四 编写feign-consumer
1 编写RefactorHelloService接口,并继承hello-service-api包中的HelloService接口,然后添加@FeignClient注解来绑定服务。
package com.didispace.web;
import org.springframework.cloud.netflix.feign.FeignClient;
@FeignClient(value = "HELLO-SERVICE")
public interface RefactorHelloService extends com.didispace.service.HelloService {
}
2 编写控制类
package com.didispace.web;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.bind.annotation.RestController;
@RestController
public class ConsumerController {
@Autowired
RefactorHelloService refactorHelloService;
@RequestMapping(value = "/feign-consumer3", method = RequestMethod.GET)
public String helloConsumer3() {
StringBuilder sb = new StringBuilder();
sb.append(refactorHelloService.hello("MIMI")).append("\n");
sb.append(refactorHelloService.hello("MIMI", 20)).append("\n");
sb.append(refactorHelloService.hello(new com.didispace.dto.User("MIMI", 20))).append("\n");
return sb.toString();
}
}
五 测试
1 先启动hello-service-api
2 再启动hello-service、feign-consumer和Eureka
3 浏览器输出http://localhost:9001/feign-consumer3