080_Feign 负载均衡

目录

• 简介
  • Feign能干什么
  • Feign集成了Ribbon
• 使用
  • 实体类子模块
    • pom.xml
    • FeignClient接口，映射到服务提供者
  • 创建feign子模块
    • pom.xml
    • application.yml
    • 配置类
    • 接口类
    • 启动类

简介

Feign能干什么

Feign集成了Ribbon

使用

实体类子模块

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/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <parent>
        <artifactId>springcloud</artifactId>
        <groupId>com.qing</groupId>
        <version>1.0-SNAPSHOT</version>
    </parent>
    <modelVersion>4.0.0</modelVersion>

    <artifactId>springcloud-api</artifactId>

    <properties>
        <maven.compiler.source>8</maven.compiler.source>
        <maven.compiler.target>8</maven.compiler.target>
    </properties>

    <!--当前module需要的依赖，如果父依赖中已经配置了版本，这里就不用写了，指向父依赖-->
    <dependencies>
        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-feign</artifactId>
            <version>1.4.6.RELEASE</version>
        </dependency>
    </dependencies>

</project>

FeignClient接口，映射到服务提供者

package com.qing.springcloud.service;

import com.qing.springcloud.pojo.Dept;
import org.springframework.cloud.openfeign.FeignClient;
import org.springframework.stereotype.Component;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PostMapping;

import java.util.List;

@FeignClient(value = "springcloud-provider-dept") // value值为服务提供者的服务名称
@Component
public interface DeptClientService {

    @PostMapping("/dept/add")
    public boolean add(Dept dept);

    @GetMapping("/dept/get/{id}")
    public Dept get(Long id);

    @GetMapping("/dept/listAll")
    public List<Dept> listAll();
}

创建feign子模块

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/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <parent>
        <artifactId>springcloud</artifactId>
        <groupId>com.qing</groupId>
        <version>1.0-SNAPSHOT</version>
    </parent>
    <modelVersion>4.0.0</modelVersion>

    <artifactId>springcloud-consumer-dept-feign-80</artifactId>

    <properties>
        <maven.compiler.source>8</maven.compiler.source>
        <maven.compiler.target>8</maven.compiler.target>
    </properties>

    <dependencies>
        <!--springcloud-api模块，实体类-->
        <dependency>
            <groupId>com.qing</groupId>
            <artifactId>springcloud-api</artifactId>
            <version>1.0-SNAPSHOT</version>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>
        <!--热部署-->
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-devtools</artifactId>
        </dependency>
        <!--服务提供者和服务消费者使用eureka，eureka服务端使用eureka-server-->
        <!-- https://mvnrepository.com/artifact/org.springframework.cloud/spring-cloud-starter-eureka -->
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-eureka</artifactId>
            <version>1.4.6.RELEASE</version>
        </dependency>
        <!-- https://mvnrepository.com/artifact/org.springframework.cloud/spring-cloud-starter-ribbon -->
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-ribbon</artifactId>
            <version>1.4.6.RELEASE</version>
        </dependency>
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-feign</artifactId>
            <version>1.4.6.RELEASE</version>
        </dependency>

    </dependencies>

</project>

application.yml

server:
  port: 80

# Eureka
eureka:
  client:
    register-with-eureka: false # 不向eureka注册自己
    service-url:
      defaultZone: http://eureka7001.com:7001/eureka/,http://eureka7002.com:7002/eureka/,http://eureka7003.com:7003/eureka/

配置类

package com.qing.springcloud.config;

import org.springframework.cloud.client.loadbalancer.LoadBalanced;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.web.client.RestTemplate;

@Configuration
public class ConfigBean {

    /**
     * 注册RestTemplate对象到Spring容器
     * @return
     */
    @Bean
    @LoadBalanced // 配置负载均衡实现RestTemplate Ribbon
    public RestTemplate getRestTemplate() {
        return new RestTemplate();
    }
}

接口类

package com.qing.springcloud.controller;

import com.qing.springcloud.pojo.Dept;
import com.qing.springcloud.service.DeptClientService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.PostMapping;
import org.springframework.web.bind.annotation.RestController;
import org.springframework.web.client.RestTemplate;

import java.util.List;

@RestController
public class DeptConsumerController {

    @Autowired
    private RestTemplate restTemplate; // 提供多种便捷访问远程http服务的方法，简单的restful服务模板

    @Autowired
    private DeptClientService deptClientService;

    @PostMapping("/consumer/dept/add")
    public boolean add(Dept dept) {
        // url 请求参数 返回值类型
        return deptClientService.add(dept);
    }

    @GetMapping("/consumer/dept/get/{id}")
    public Dept get(@PathVariable("id") Long id) {
        // url 请求参数（可以不传） 返回值类型
        return deptClientService.get(id);
    }

    @GetMapping("/consumer/dept/listAll")
    public List<Dept> listAll() {
        // url 请求参数（可以不传） 返回值类型
        return deptClientService.listAll();
    }
}

启动类

package com.qing.springcloud;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.cloud.netflix.eureka.EnableEurekaClient;

@EnableFeignClients(basePackages = {"com.qing.springcloud"})
@EnableEurekaClient
@SpringBootApplication
public class DeptConsumerFeign_80 {
    public static void main(String[] args) {
        SpringApplication.run(DeptConsumerFeign_80.class, args);
    }
}