微服务Feign(五)

Feign是什么

简单来说就是针对接口编程的负载均衡
Ribbon和Feign都是客户端负载均衡，有什么区别呢，
Feign集成Ribbon,针对微服务，针对接口的，声明式负载均衡
Ribbon是针对微服务，针对RestTemplate的负载均衡
参考之前的consumer 80 来做Feign

pom

    <?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>cloud2018</artifactId>
            <groupId>com.tzy.spring</groupId>
            <version>1.0-SNAPSHOT</version>
        </parent>
        <modelVersion>4.0.0</modelVersion>

        <artifactId>cloud-consumer-dept-feign</artifactId>

        <dependencies>
            <dependency><!-- 自己定义的api -->
                <artifactId>cloud-api</artifactId>
                <groupId>com.tzy.spring</groupId>
                <version>1.0-SNAPSHOT</version>
            </dependency>
            <dependency>
                <groupId>org.springframework.cloud</groupId>
                <artifactId>spring-cloud-starter-feign</artifactId>
            </dependency>
            <!-- Ribbon相关 -->
            <dependency>
                <groupId>org.springframework.cloud</groupId>
                <artifactId>spring-cloud-starter-eureka</artifactId>
            </dependency>
            <dependency>
                <groupId>org.springframework.cloud</groupId>
                <artifactId>spring-cloud-starter-ribbon</artifactId>
            </dependency>
            <dependency>
                <groupId>org.springframework.cloud</groupId>
                <artifactId>spring-cloud-starter-config</artifactId>
            </dependency>
            <dependency>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-starter-web</artifactId>
            </dependency>
            <!-- 修改后立即生效，热部署 -->
            <dependency>
                <groupId>org.springframework</groupId>
                <artifactId>springloaded</artifactId>
            </dependency>
            <dependency>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-devtools</artifactId>
            </dependency>
        </dependencies>
    </project>

>application.yml

server:
  port: 80
  
  
eureka:
  client:
    register-with-eureka: false    #取消注册自己
    service-url: 
      defaultZone: http://eureka7001.com:7001/eureka/,http://eureka7002.com:7002/eureka/,http://eureka7003.com:7003/eureka/  

>修改api工程加入新的DeptClientService.java 加入feign引用

    <dependency>
        <groupId>org.springframework.cloud</groupId>
        <artifactId>spring-cloud-starter-feign</artifactId>
    </dependency>

	import com.tzy.spring.entities.Dept;
	import org.springframework.cloud.netflix.feign.FeignClient;
	import org.springframework.web.bind.annotation.PathVariable;
	import org.springframework.web.bind.annotation.RequestMapping;
	import org.springframework.web.bind.annotation.RequestMethod;
	import java.util.List;
	
	@FeignClient(value = "CLOUD-DEPT")
	public interface DeptClientService
	{
		@RequestMapping(value = "/dept/get/{id}", method = RequestMethod.GET)
		public Dept get(@PathVariable("id") long id);
	
		@RequestMapping(value = "/dept/list", method = RequestMethod.GET)
		public List<Dept> list();
	
		@RequestMapping(value = "/dept/add", method = RequestMethod.POST)
		public boolean add(Dept dept);
	}

>修改新工程DeptController_Consumer.java

	import com.tzy.spring.entities.Dept;
	import com.tzy.spring.service.DeptClientService;
	import org.springframework.beans.factory.annotation.Autowired;
	import org.springframework.web.bind.annotation.PathVariable;
	import org.springframework.web.bind.annotation.RequestMapping;
	import org.springframework.web.bind.annotation.RestController;
	
	import java.util.List;
	
	@RestController
	public class DeptController_Consumer
	{
	
		@Autowired
		private DeptClientService service;
	
		@RequestMapping(value = "/consumer/dept/get/{id}")
		public Dept get(@PathVariable("id") Long id)
		{
			return this.service.get(id);
		}
	
		@RequestMapping(value = "/consumer/dept/list")
		public List<Dept> list()
		{
			return this.service.list();
		}
	
		@RequestMapping(value = "/consumer/dept/add")
		public Object add(Dept dept)
		{
			return this.service.add(dept);
		}
	
	}

>启动类

	import org.springframework.boot.SpringApplication;
	import org.springframework.boot.autoconfigure.SpringBootApplication;
	import org.springframework.cloud.netflix.eureka.EnableEurekaClient;
	import org.springframework.cloud.netflix.feign.EnableFeignClients;
	import org.springframework.context.annotation.ComponentScan;
	
	@SpringBootApplication
	@EnableEurekaClient
	@EnableFeignClients(basePackages= {"com.tzy.spring"})
	@ComponentScan("com.tzy.spring")
	public class DeptConsumerFeign_App
	{
		public static void main(String[] args)
		{
			SpringApplication.run(DeptConsumerFeign_App.class, args);
		}
	}

>启动看效果7001-3,8001-3,feign，访问[http://localhost/consumer/dept/list](http://localhost/consumer/dept/list)   >我更喜欢这种，你喜欢什么样呢？