springcloud+eureka+feign负载均衡-蒲公英云

目前，在Spring cloud 中服务之间通过restful方式调用有两种方式

restTemplate+Ribbon
feign
现在咱们采用feign进行负载均衡，他的好处就是可以实现接口式的负载均衡，符合接口式的开发规范，而不是像ribbon，要结合restTemplate，通过Feign直接找到服务接口，由于在进行服务调用的时候融合了Ribbon技术，所以也支持负载均衡作用。

服务如下：
注意这里没有的dept-80服务，它被dept-feign服务代替。
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1 microservicecloud-api

它主要为其他服务提供实体类和接口服务，打成，写成后打成jar即可
我们也可以将feign服务接口写在dept-feign服务里面，但是这些接口可能会被其他服务所调用，所以建议写在api中。
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pom.xml

<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">
    <modelVersion>4.0.0</modelVersion>
    <parent>
        <groupId>com.wuk.springcloud</groupId>
        <artifactId>microservicecloud</artifactId>
        <version>0.0.1-SNAPSHOT</version>
    </parent>
    <artifactId>microservicecloud-api</artifactId>
    <dependencies><!-- 当前Module需要用到的jar包，按自己需求添加，如果父类已经包含了，可以不用写版本号 -->
        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-feign</artifactId>
        </dependency>
    </dependencies>
</project>

DeptClientService.java

package com.wuk.service;
import java.util.List;
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 com.wuk.entity.Dept;
@FeignClient(value = "producers")
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);
}

然后将其打成jar，引入到其他服务中。

2 microservicecloud-consumer-dept-feign

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pom.xml

<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">
    <modelVersion>4.0.0</modelVersion>
    <parent>
        <groupId>com.wuk.springcloud</groupId>
        <artifactId>microservicecloud</artifactId>
        <version>0.0.1-SNAPSHOT</version>
    </parent>
    <artifactId>microservicecloud-consumer-dept-feign</artifactId>
    <dependencies>
        <dependency>
            <groupId>com.wuk.springcloud</groupId>
            <artifactId>microservicecloud-api</artifactId>
            <version>${project.version}</version>
        </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>
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-eureka</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-config</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-feign</artifactId>
        </dependency>
    </dependencies>
</project>

application.yml

server:
  port: 80
eureka:
  client:
    register-with-eureka: false
    service-url: 
      defaultZone: http://127.0.0.1:7001/eureka/

DeptController_Consumer.java

package com.wuk.controller;
import java.util.List;
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 com.wuk.entity.Dept;
import com.wuk.service.DeptClientService;
@RestController
public class DeptController_Consumer { 
    @Autowired
    private DeptClientService service = null;
    @RequestMapping(value = "/consumer/dept/add")
    public boolean add(Dept dept) { 
        return service.add(dept);
    }
    @RequestMapping(value = "/consumer/dept/get/{id}")
    public Dept get(@PathVariable("id") Long id) { 
        return service.get(id);
    }
    @SuppressWarnings("unchecked")
    @RequestMapping(value = "/consumer/dept/list")
    public List<Dept> list() { 
        return service.list();
    }
}

DeptConsumer80_Feign_App.java

package com.wuk;
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.wuk"})
@ComponentScan("com.wuk")
public class DeptConsumer80_Feign_App { 
    public static void main(String[] args) { 
        SpringApplication.run(DeptConsumer80_Feign_App.class, args);
    }
}