spring cloud之Feign的使用_架构

spring cloud之Feign的使用

原始的调用客户端的方式是通过注入resttemplate的方式

resttemplate.getforobject("http://client/hello", string.class)

通过feign的方式

配置消费者项目cloud-consume

pom.xml

依赖jar

<dependency>
            <groupid>org.springframework.cloud</groupid>
            <artifactid>spring-cloud-starter-openfeign</artifactid>
        </dependency>

application.yml

添加启动feign 可实现错误回调

feign:
  hystrix:
    enabled: true

启动应用类

clondconsumeapplication.java

添加注解@enablefeignclients

helloservice.java接口

package com.tp.soft.cloudconsume.service;

import com.tp.soft.cloudconsume.service.impl.helloservicefallback;
import org.springframework.cloud.openfeign.feignclient;
import org.springframework.web.bind.annotation.getmapping;

@feignclient(value = "client", fallback = helloservicefallback.class)
public interface helloservice {
    @getmapping("/hello")
    string hello();
}

其中client则为注册中心被调用的应用名,/hello完全和客户端业务接口一样,fallback则为错误回调的方法

helloservicefallback.java接口

package com.tp.soft.cloudconsume.service.impl;

import com.tp.soft.cloudconsume.service.helloservice;
import org.springframework.stereotype.component;

@component
public class helloservicefallback implements helloservice {
    @override
    public string hello() {

        return "request error";
    }
}

hellocontroller.java

package com.tp.soft.cloudconsume.controller;

import com.tp.soft.cloudconsume.service.helloservice;
import org.springframework.beans.factory.annotation.autowired;
import org.springframework.web.bind.annotation.getmapping;
import org.springframework.web.bind.annotation.restcontroller;
import org.springframework.web.client.resttemplate;

import javax.annotation.resource;

@restcontroller
public class hellocontroller {

//    @autowired
//    resttemplate resttemplate;

    @resource
    private helloservice helloservice;

    @getmapping("hi")
    public string hi(){
        //return resttemplate.getforobject("http://client/hello", string.class);
        return helloservice.hello();
    }
}

和原来在controller调用接口一模一样的去调用就可以了

最后的效果: