springcloud(四) ribbon和feign

Ribbon使用

order-service工程：

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">
  <modelVersion>4.0.0</modelVersion>
  <groupId>com.tuling.cloud</groupId>
  <artifactId>microservice-consumer-order-ribbon</artifactId>
  <version>0.0.1-SNAPSHOT</version>
  <packaging>jar</packaging>
  <name>05-ms-consumer-order-ribbon</name>

  <!-- 引入spring boot的依赖 -->
  <parent>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-parent</artifactId>
    <version>1.5.9.RELEASE</version>
  </parent>

  <properties>
    <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
    <java.version>1.8</java.version>
  </properties>

  <dependencies>
    <dependency>
      <groupId>org.springframework.boot</groupId>
      <artifactId>spring-boot-starter-web</artifactId>
    </dependency>
    <dependency>
      <groupId>org.springframework.boot</groupId>
      <artifactId>spring-boot-starter-actuator</artifactId>
    </dependency>

    <!-- 已经包含了ribbon包-->
    <dependency>
      <groupId>org.springframework.cloud</groupId>
      <artifactId>spring-cloud-starter-netflix-eureka-client</artifactId>
    </dependency>
  </dependencies>

  <!-- 引入spring cloud的依赖 -->
  <dependencyManagement>
    <dependencies>
      <dependency>
        <groupId>org.springframework.cloud</groupId>
        <artifactId>spring-cloud-dependencies</artifactId>
        <version>Edgware.RELEASE</version>
        <type>pom</type>
        <scope>import</scope>
      </dependency>
    </dependencies>
  </dependencyManagement>

  <!-- 添加spring-boot的maven插件 -->
  <build>
    <plugins>
      <plugin>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-maven-plugin</artifactId>
      </plugin>
    </plugins>
  </build>
</project>

ConsumerOrderApplication.java:

package com.jiagoushi.cloud.study;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.cloud.client.discovery.EnableDiscoveryClient;
import org.springframework.cloud.client.loadbalancer.LoadBalanced;
import org.springframework.context.annotation.Bean;
import org.springframework.web.client.RestTemplate;

/**
 * 演示默认的轮询的负载均衡
 */
@EnableDiscoveryClient
@SpringBootApplication
public class ConsumerOrderApplication {

  @Bean
  @LoadBalanced //ribbon的负载均衡注解，RestTemplate就具有了负载均衡
  public RestTemplate restTemplate() {
    return new RestTemplate();
  }

  public static void main(String[] args) {
    SpringApplication.run(ConsumerOrderApplication.class, args);
  }
}

　OrderController.java　

package com.jiagoushi.cloud.study.user.controller;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.cloud.client.ServiceInstance;
import org.springframework.cloud.client.loadbalancer.LoadBalancerClient;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RestController;
import org.springframework.web.client.RestTemplate;

import com.jiagoushi.cloud.study.user.entity.User;

import java.util.HashMap;
import java.util.Map;

@RestController
public class OrderController {

    private static final Logger LOGGER = LoggerFactory.getLogger(OrderController.class);

    @Autowired
    private RestTemplate restTemplate;

    @Autowired
    private LoadBalancerClient loadBalancerClient;

    @GetMapping("/order")
    public Map testOrder() {
        Map<String ,Object> map = new HashMap<>();
        map.put("测试服务是否启动","ok");
        return map;
    }

    @GetMapping("/user/{id}")
    public User findById(@PathVariable Long id) {
        return this.restTemplate.getForObject("http://microservice-provider-user/" + id, User.class);
    }

    @GetMapping("/user/getIpAndPort")
    public String getIpAndPort() {
        return this.restTemplate.getForObject("http://microservice-provider-user/getIpAndPort", String.class);
    }

    @GetMapping("/log-user-instance")
    public void logUserInstance() {
        ServiceInstance serviceInstance = this.loadBalancerClient.choose("microservice-provider-user");
        // 打印当前选择的是哪个节点
        OrderController.LOGGER.info("{}:{}:{}", serviceInstance.getServiceId(), serviceInstance.getHost(), serviceInstance.getPort());
    }
}

　　启动order服务调用user服务的时候就是采用了轮询。

---

user-service 工程：

　　

UserController.java:

package com.jiagoushi.cloud.study.controller;

import com.jiagoushi.cloud.study.repository.UserRepository;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.cloud.client.serviceregistry.Registration;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RestController;

import java.util.HashMap;
import java.util.Map;

@RestController
public class UserController {

  @Autowired
  private UserRepository userRepository;

  @Autowired
  private Registration registration;

  @GetMapping("/user")
  public Map testUser() {
    Map<String,Object> map = new HashMap<>();
    map.put("测试user服务","OK");
    return map;
  }

  @GetMapping("/{id}")
  public com.jiagoushi.cloud.study.entity.User findById(@PathVariable Long id) {
    com.jiagoushi.cloud.study.entity.User findOne = userRepository.findOne(id);
    return findOne;
  }
  
  @GetMapping("/getIpAndPort")
  public String findById() {
	  return registration.getHost() + ":" + registration.getPort();
  }
}

　　

分别改为 8001 和 8002 端口启动，注册中心别忘了启动

注意：

测试结果：

 发现order服务是轮询调用user服务的。

 在配置文件可以指定某个服务使用Ribbon某个策略：

 

---

 

 Ribbon脱离Eureka独立使用

 

 Ribbon配置的优先级：属性配置 > JAVA配置（注解和配置类）>Netflix Ribbon默认配置

---

Feign使用

order-feign工程：

order 服务pom.xml 添加依赖：

<?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">
  <modelVersion>4.0.0</modelVersion>
  <groupId>com.tuling.cloud</groupId>
  <artifactId>microservice-consumer-order-feign</artifactId>
  <version>0.0.1-SNAPSHOT</version>
  <packaging>jar</packaging>

  <!-- 引入spring boot的依赖 -->
  <parent>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-parent</artifactId>
    <version>1.5.9.RELEASE</version>
  </parent>

  <properties>
    <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
    <java.version>1.8</java.version>
  </properties>

  <dependencies>
    <dependency>
      <groupId>org.springframework.boot</groupId>
      <artifactId>spring-boot-starter-web</artifactId>
    </dependency>
    <dependency>
      <groupId>org.springframework.boot</groupId>
      <artifactId>spring-boot-starter-actuator</artifactId>
    </dependency>

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

    <!-- feign 依赖-->
    <dependency>
      <groupId>org.springframework.cloud</groupId>
      <artifactId>spring-cloud-starter-openfeign</artifactId>
    </dependency>
    
    <dependency>
	  <groupId>com.tuling.cloud</groupId>
	  <artifactId>microservice-provider-user-api</artifactId>
	  <version>0.0.1-SNAPSHOT</version>
	</dependency>
  </dependencies>

  <!-- 引入spring cloud的依赖 -->
  <dependencyManagement>
    <dependencies>
      <dependency>
        <groupId>org.springframework.cloud</groupId>
        <artifactId>spring-cloud-dependencies</artifactId>
        <version>Edgware.RELEASE</version>
        <type>pom</type>
        <scope>import</scope>
      </dependency>
    </dependencies>
  </dependencyManagement>

  <!-- 添加spring-boot的maven插件 -->
  <build>
    <plugins>
      <plugin>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-maven-plugin</artifactId>
      </plugin>
    </plugins>
  </build>
</project>

　　ConsumerOrderApplication.java:

package com.jiagoushi.cloud.study;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.cloud.client.discovery.EnableDiscoveryClient;
import org.springframework.cloud.netflix.feign.EnableFeignClients;

@EnableDiscoveryClient
@SpringBootApplication
// feign 支持
@EnableFeignClients
public class ConsumerOrderApplication {
  public static void main(String[] args) {
    SpringApplication.run(ConsumerOrderApplication.class, args);
  }
}

　　OrderController.java

package com.jiagoushi.cloud.study.user.controller;

import com.jiagoushi.cloud.study.user.entity.User;
import com.jiagoushi.cloud.study.user.feign.RefactorUserService;
import com.jiagoushi.cloud.study.user.feign.UserFeignClient;
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.RestController;

@RestController
public class OrderController {

  @Autowired
  private UserFeignClient userFeignClient; // 为了学习
  
  @GetMapping("/user/{id}")
  public User findById(@PathVariable Long id) {
    return userFeignClient.findById2(id);
  }
  
  @GetMapping("/user-extends/{id}")
  public com.jiagoushi.cloud.api.entity.User findById2(@PathVariable Long id) {
	  return refactorUserService.getUser(id);
  }
  
}

　　UserFeignClient.java

package com.jiagoushi.cloud.study.user.feign;

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.jiagoushi.cloud.study.user.entity.User;

@FeignClient(name = "microservice-provider-user")
public interface UserFeignClient {

  @RequestMapping(value = "/{id}", method = RequestMethod.GET) //指名要调用的url
  public User findById2(@PathVariable("id") Long id); // 方法名称随便写，但是最好与提供方一样，参数和提供方列表参数的顺序一致
}

　　

 欢迎来QQ群：592495675 一起研究 java技术，群里技术大佬，还有所有源代码