SpringCloud和SpringBoot的負載均衡的實現辦法LoadBalanced+ConfigBean+RestTemplate轉發操作

 實例化RestTemplate---負載均衡

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;

import com.netflix.loadbalancer.IRule;
import com.netflix.loadbalancer.RetryRule;

@Configuration
public class ConfigBean //boot -->spring   applicationContext.xml --- @Configuration配置   ConfigBean = applicationContext.xml
{ 
	@Bean
	@LoadBalanced//Spring Cloud Ribbon是基於Netflix Ribbon實現的一套客戶端       負載均衡的工具。
	public RestTemplate getRestTemplate()
	{
		return new RestTemplate();
	}
	
	@Bean
	public IRule myRule()
	{
		//return new RoundRobinRule();
		//return new RandomRule();//達到的目的，用我們重新選擇的隨機算法替代默認的輪詢。
		return new RetryRule();
	}
}

 DeptController_Consumer實現請求轉化

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 org.springframework.web.client.RestTemplate;

import com.atguigu.springcloud.entities.Dept;

@RestController
public class DeptController_Consumer
{

 
	private static final String REST_URL_PREFIX = "http://MICROSERVICECLOUD-DEPT";

	/**
	 * 使用 使用restTemplate訪問restful接口非常的簡單粗暴無腦。 (url, requestMap,
	 * ResponseBean.class)這三個參數分別代表 REST請求地址、請求參數、HTTP響應轉換被轉換成的對象類型。
	 */
	@Autowired
	private RestTemplate restTemplate;

	@RequestMapping(value = "/consumer/dept/add")
	public boolean add(Dept dept)
	{
		return restTemplate.postForObject(REST_URL_PREFIX + "/dept/add", dept, Boolean.class);
	}

	@RequestMapping(value = "/consumer/dept/get/{id}")
	public Dept get(@PathVariable("id") Long id)
	{
		return restTemplate.getForObject(REST_URL_PREFIX + "/dept/get/" + id, Dept.class);
	}

	@SuppressWarnings("unchecked")
	@RequestMapping(value = "/consumer/dept/list")
	public List<Dept> list()
	{
		return restTemplate.getForObject(REST_URL_PREFIX + "/dept/list", List.class);
	}

	// 測試@EnableDiscoveryClient,消費端可以調用服務發現
	@RequestMapping(value = "/consumer/dept/discovery")
	public Object discovery()
	{
		return restTemplate.getForObject(REST_URL_PREFIX + "/dept/discovery", Object.class);
	}

}

啓動類：

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

import com.atguigu.myrule.MySelfRule;

@SpringBootApplication
@EnableEurekaClient
//在啓動該微服務的時候就能去加載我們的自定義Ribbon配置類，從而使配置生效
//@RibbonClient(name="MICROSERVICECLOUD-DEPT",configuration=MySelfRule.class)
@RibbonClient(name="MICROSERVICECLOUD-DEPT",configuration=MySelfRule.class)
public class DeptConsumer80_App
{
	public static void main(String[] args)
	{
		SpringApplication.run(DeptConsumer80_App.class, args);
	}
}

自定義負載均衡的規則

import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;

import com.netflix.loadbalancer.IRule;
import com.netflix.loadbalancer.RoundRobinRule;

@Configuration
public class MySelfRule
{
	@Bean
	public IRule myRule()
	{
		//return new RandomRule();// Ribbon默認是輪詢，我自定義爲隨機
		//return new RoundRobinRule();// Ribbon默認是輪詢，我自定義爲隨機
		
		return new RandomRule_ZY();// 我自定義爲每臺機器5次
	}
}

實現Irule規則的實現，負載均衡的實現

import java.util.List;

import com.netflix.client.config.IClientConfig;
import com.netflix.loadbalancer.AbstractLoadBalancerRule;
import com.netflix.loadbalancer.ILoadBalancer;
import com.netflix.loadbalancer.Server;

public class RandomRule_ZY extends AbstractLoadBalancerRule
{

	// total = 0 // 當total==5以後，我們指針才能往下走，
	// index = 0 // 當前對外提供服務的服務器地址，
	// total需要重新置爲零，但是已經達到過一個5次，我們的index = 1
	// 分析：我們5次，但是微服務只有8001 8002 8003 三臺，OK？
	// 
	
	
	private int total = 0; 			// 總共被調用的次數，目前要求每臺被調用5次
	private int currentIndex = 0;	// 當前提供服務的機器號

	public Server choose(ILoadBalancer lb, Object key)
	{
		if (lb == null) {
			return null;
		}
		Server server = null;

		while (server == null) {
			if (Thread.interrupted()) {
				return null;
			}
			List<Server> upList = lb.getReachableServers();
			List<Server> allList = lb.getAllServers();

			int serverCount = allList.size();
			if (serverCount == 0) {
				/*
				 * No servers. End regardless of pass, because subsequent passes only get more
				 * restrictive.
				 */
				return null;
			}

//			int index = rand.nextInt(serverCount);// java.util.Random().nextInt(3);
//			server = upList.get(index);

			
//			private int total = 0; 			// 總共被調用的次數，目前要求每臺被調用5次
//			private int currentIndex = 0;	// 當前提供服務的機器號
            if(total < 5)
            {
	            server = upList.get(currentIndex);
	            total++;
            }else {
	            total = 0;
	            currentIndex++;
	            if(currentIndex >= upList.size())
	            {
	              currentIndex = 0;
	            }
            }			
			
			
			if (server == null) {
				/*
				 * The only time this should happen is if the server list were somehow trimmed.
				 * This is a transient condition. Retry after yielding.
				 */
				Thread.yield();
				continue;
			}

			if (server.isAlive()) {
				return (server);
			}

			// Shouldn't actually happen.. but must be transient or a bug.
			server = null;
			Thread.yield();
		}

		return server;

	}

	@Override
	public Server choose(Object key)
	{
		return choose(getLoadBalancer(), key);
	}

	@Override
	public void initWithNiwsConfig(IClientConfig clientConfig)
	{
		// TODO Auto-generated method stub

	}

}

XML的配置

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