详解SpringCloud负载均衡重要组件Ribbon中重要类的用法

//省略必要的package和import代码
  public class ILoadBalancerDemo {
    public static void main(String[] args){
      //创建ILoadBalancer的对象 
      ILoadBalancer loadBalancer = new BaseLoadBalancer();
      //定义一个服务器列表
       List myServers = new ArrayList();
      //创建两个Server对象
      Server s1 = new Server("ekserver1",8080);
      Server s2 = new Server("ekserver2",8080);
      //两个server对象放入List类型的myServers对象里  
      myServers.add(s1);
      myServers.add(s2);
      //把myServers放入负载均衡器
      loadBalancer.addServers(myServers);
      //在for循环里发起10次调用
      for(int i=0;i<10;i++){
      //用基于默认的负载均衡规则获得Server类型的对象
        Server s = loadBalancer.chooseServer("default");
      //输出IP地址和端口号
        System.out.println(s.getHost() + ":" + s.getPort());
      }    
   }
  }

ekserver2:8080
  ekserver1:8080
  ekserver2:8080
  ekserver1:8080
  ekserver2:8080
  ekserver1:8080
  ekserver2:8080
  ekserver1:8080
  ekserver2:8080
 ekserver1:8080

 //省略必要的package和import代码
  public class IRuleDemo {
    public static void main(String[] args){
    //请注意这是用到的是BaseLoadBalancer，而不是ILoadBalancer接口
    BaseLoadBalancer loadBalancer = new BaseLoadBalancer();
      //声明基于轮询的负载均衡策略
      IRule rule = new RoundRobinRule();
    //在负载均衡器里设置策略 
      loadBalancer.setRule(rule);
      //如下定义3个Server，并把它们放入List类型的集合中
      List myServers = new ArrayList();
      Server s1 = new Server("ekserver1",8080);
      Server s2 = new Server("ekserver2",8080);
      Server s3 = new Server("ekserver3",8080);
      myServers.add(s1);
      myServers.add(s2);
      myServers.add(s3);
      //在负载均衡器里设置服务器的List
      loadBalancer.addServers(myServers);
      //输出负载均衡的结果
      for(int i=0;i<10;i++){
        Server s = loadBalancer.chooseServer(null);
        System.out.println(s.getHost() + ":" + s.getPort());  
     }    
    }
  }

IRule rule = new RandomRule();  

//省略必要的package和import代码
  class MyPing implements IPing {
    public boolean isAlive(Server server) {
      //如果服务器名是ekserver2，则返回false
      if (server.getHost().equals("ekserver2")) {
        return false;
      }
      return true;
    }
  }

public class IRuleDemo {
    public static void main(String[] args) {
      BaseLoadBalancer loadBalancer = new BaseLoadBalancer();
      //定义IPing类型的myPing对象
      IPing myPing = new MyPing(); 
      //在负载均衡器里使用myPing对象
      loadBalancer.setPing(myPing);
      //同样是创建三个Server对象并放入负载均衡器
      List myServers = new ArrayList();
      Server s1 = new Server("ekserver1", 8080);
      Server s2 = new Server("ekserver2", 8080);
      Server s3 = new Server("ekserver3", 8080);
      myServers.add(s1);
      myServers.add(s2);
      myServers.add(s3);
      loadBalancer.addServers(myServers);
      //通过for循环多次请求服务器 
      for (int i = 0; i <10; i++) {
        Server s = loadBalancer.chooseServer(null);
        System.out.println(s.getHost() + ":" + s.getPort());
      }
    }
  }