Fiegn 声明式接口调用

五：Fiegn 声明式接口调用

什么是Fiegn

Netfix，Fiegn 是一个提供模板式的Web Service客户端，使用Fiegn 可以简化Web Service 客户端的编写，开发者可以通过简单的接口和注解来调用HTTP API

Spring Cloud Fiegn ：可插拔、基于注解、负载均衡、服务器熔断

只需要创建接口，同时在接口上添加关注注解即可

Fiegn 和Ribbion的区别：

• Ribbion是一个HTTP客户端工具，Fiegn 是基于Ribbion，更加灵动
• 支持Fiegn 注解，spring mvc 注解
• Fiegn 基于Ribbion实现
• Fiegn 集成了Hystrix

1.创建模块，配置环境

<?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">
    <parent>
        <artifactId>springCloud01</artifactId>
        <groupId>org.example</groupId>
        <version>1.0-SNAPSHOT</version>
    </parent>
    <modelVersion>4.0.0</modelVersion>

    <artifactId>feign</artifactId>

    <dependencies>
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-netflix-eureka-client</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-openfeign</artifactId>
        </dependency>
    </dependencies>
</project>

2.配置文件

server:
  port: 8050
spring:
  application:
    name: fegin
eureka:
  client:
    service-url:
      defaultZone: http://localhost:8761/eureka/
  instance:
    prefer-ip-address: true

3.启动类

package com.southwind;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.cloud.openfeign.EnableFeignClients;

@SpringBootApplication
@EnableFeignClients
public class feignApplication {
    public static void main(String[] args) {
        SpringApplication.run(feignApplication.class,args);
    }
}

4.Handler

package com.southwind.Handler;

import com.southwind.entity.Student;
import com.southwind.fegin.FeignProviderClient;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.*;

import java.util.Collection;

@RestController
@RequestMapping("/feign")
public class FeignHandler {
    @Autowired
    private FeignProviderClient feignProviderClient;

    @GetMapping("/findall")
    public Collection<Student> findall(){
        return feignProviderClient.findall();
    }
    @GetMapping("/findbyid/{id}")
    public Student findbyid(@PathVariable("id") Integer id){
        return feignProviderClient.findbyid(id);
    }
    @PostMapping("/save")
    public void save(@RequestBody Student student){
        feignProviderClient.save(student);
    }
    @DeleteMapping("/delete")
    public void deletebyid(Integer id){
        feignProviderClient.delete(id);
    }
}

5.声明的接口：

package com.southwind.fegin;

import com.southwind.entity.Student;
import org.springframework.cloud.openfeign.FeignClient;
import org.springframework.web.bind.annotation.*;

import java.util.Collection;

@FeignClient(value = "provider")
public interface FeignProviderClient {
    @GetMapping("/provider/findall")
    public Collection<Student> findall();
    @GetMapping("/provider/findbyid/{id}")
    public Student findbyid(@PathVariable("id") Integer id);
    @PostMapping("/provider/save")
    public void save(@RequestBody Student student);
    @DeleteMapping("/provider/delete/{id}")
    public void delete(@PathVariable("id") Integer id);
}