spring-cloud 2.X 声明式服务 feign（openfeign）基本配置

准备工作 ，三个工程如下：

• feign-api
• feign-core
• feign-consumer

一、feign-api创建

1、引入依赖

	org.springframework.boot
	spring-boot-starter-web

2、创建一个实体对象|Student

public class Student{
	private String name;
	private int age;
	
	public Student() {
		super();
	}
	
	public Student(String name,int age) {
		super();
		this.name = name;
		this.age = age;
	}

	//......get set 省略......
}

3、创建一个facade接口

@RequestMapping("/student")
public interface StudentFacade {

	@GetMapping("list")
	public List list();
	
	@GetMapping("get")
	public Student get(@RequestParam("id") int id);
	
	@PostMapping("add")
	public Student add(@RequestBody Student student);
}

4、中创建一个基本的启动类，实际上启动类用不到，但是不加上打包会不成功

@SpringBootApplication
public class YmSpringbootFeignApplication {

	public static void main(String[] args) {
		SpringApplication.run(YmSpringbootFeignApplication.class, args);
	}

}

二、feign-core创建

1、引入依赖

	org.springframework.boot
	spring-boot-starter-web


	org.springframework.cloud
	spring-cloud-starter-netflix-eureka-client
	2.1.0.RELEASE


	com.ym.springboot.facade
	feign-api
	0.0.1-SNAPSHOT

2、创建一个实现类StudentFacadeImpl实现feign-api中的接口StudentFacade

@RestController
public class StudentFacadeImpl implements StudentFacade{
	
	@GetMapping("list")
	@Override
	public List list(){
		List list = new ArrayList();
		list.add(new Student("A同学", 13));
		list.add(new Student("B同学", 16));
		list.add(new Student("C同学", 18));
		return list;
	}

	@GetMapping("get")
	@Override
	public Student get(int id) {
		return new Student("B同学", 16);
	}

	@PostMapping("add")
	@Override
	public Student add(@RequestBody Student student) {
		return student;
	}
}

3、创建一个启动类，加上@EnableEurekaClient注解

@EnableEurekaClient
@SpringBootApplication
public class YmSpringbootFeignApplication {

	public static void main(String[] args) {
		SpringApplication.run(YmSpringbootFeignApplication.class, args);
	}
}

4、application.yml

spring:
  application:
    name: feign-core

server: 
  port: 8084
  
eureka:
  client:
    serviceUrl: 
      defaultZone: http://user:123456@eureka1:8761/eureka/,http://user:123456@eureka2:8761/eureka/

 

三、feign-consumer创建

1、引入依赖

	org.springframework.boot
	spring-boot-starter-web


	org.springframework.cloud
	spring-cloud-starter-netflix-eureka-client
	2.1.0.RELEASE


	com.ym.springboot.facade
	feign-api
	0.0.1-SNAPSHOT


	org.springframework.cloud
	spring-cloud-starter-openfeign
	2.1.0.RELEASE

2、创建一个 接口继承StudentFacade接口，这里通过feign获取到eureka中注册的服务feign-core

@FeignClient(name="feign-core")
public interface StudentService extends StudentFacade{
}

3、创建调用

package com.ym.springboot.consumer.controller;


import java.util.List;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RequestParam;
import org.springframework.web.bind.annotation.RestController;

import com.ym.springboot.consumer.service.StudentService;
import com.ym.springboot.facade.domain.Student;


@RestController
public class StudentController {
	
	@Autowired
	private StudentService studentService;
	
	/**
	 * GET无参调用
	 * @return
	 */
	@GetMapping("list")
	public List list(){
		return studentService.list();
	}
	
	/**
	 * GET参数调用
	 * @param id
	 * @return
	 */
	@GetMapping("get")
	public Student get(@RequestParam("id") int id){
		return studentService.get(id);
	}
	
	
	/**
	 * POST调用
	 * @param student
	 * @return
	 */
	@GetMapping("add")
	public Student add(){
		Student student = new Student("JAVA",12);
		return studentService.add(student);
	}
}

4、application.yml

spring:
  application:
    name: feign-consumer

server: 
  port: 8085
  compression:
    enabled: true #开启GZIP压缩，以1.X版本的时候还需要配置类型，2.X设置了默认类型和默认大小
  
eureka:
  client:
    serviceUrl: 
      defaultZone: http://user:123456@eureka1:8761/eureka/,http://user:123456@eureka2:8761/eureka/


feign:
  httpclient:
    enabled: true  #启用httpclient

四、测试