SpringCloud系列(五)——Ribbon实现

妖狐艹你老母 2022-05-27 08:09 206阅读 0赞

上篇[SpringCloud系列(四)——Ribbon负载均衡][SpringCloud_Ribbon]介绍了Ribbon负载均衡，都是理论性的东西，接下来用代码实现一下。

*  新建一个简单的Springboot项目——ribbon-service，然后编写一个方法，开启两个端口启动项目。

@RequestMapping(value = "/person", method = RequestMethod.GET, 
                produces = MediaType.APPLICATION_JSON_VALUE)
        public Person getPerson(HttpServletRequest request){
            Person p = new Person();
            p.setId(1);
            p.setName("小米");
            p.setMessage(request.getRequestURL().toString());
            return p;
        }

*  新建一个简单的maven项目，通过简单的main方法访问ribbon-service：

public static void main(String[] args) throws Exception {
            ConfigurationManager.getConfigInstance().setProperty(
                    "my-client.ribbon.listOfServers", "localhost:8080,localhost:8081"); 
            RestClient client = (RestClient) ClientFactory.getNamedClient("my-client"); 
            HttpRequest request = HttpRequest.newBuilder().uri(("/person")).build();
            for(int i = 0;i<10;i++){ 
                HttpResponse response = client.executeWithLoadBalancer(request); 
                String json = response.getEntity(String.class);
                System.out.println(json);
            }
    
        }

*  输出，可以看到Ribbon的默认策略就是RoundRobinRule（轮换）：

{"id":1,"name":"小米","message":"http://localhost:8081/person"}
    {"id":1,"name":"小米","message":"http://localhost:8080/person"}
    {"id":1,"name":"小米","message":"http://localhost:8081/person"}
    {"id":1,"name":"小米","message":"http://localhost:8080/person"}
    {"id":1,"name":"小米","message":"http://localhost:8081/person"}
    {"id":1,"name":"小米","message":"http://localhost:8080/person"}
    {"id":1,"name":"小米","message":"http://localhost:8081/person"}
    {"id":1,"name":"小米","message":"http://localhost:8080/person"}
    {"id":1,"name":"小米","message":"http://localhost:8081/person"}
    {"id":1,"name":"小米","message":"http://localhost:8080/person"}

*  接下来自定义策略，新建一个类，实现IRule，重写choose():

public class MyRule implements IRule { 
    
        private ILoadBalancer lb;
    
        public Server choose(Object key) {
            Random r= new Random();
            int num = r.nextInt(10);
    
            List<Server> servers =  lb.getAllServers();
    
            if(num > 7){
                return getServerByPost(servers,8081);
            }else{
                return getServerByPost(servers,8080);
            }
    
        }
    
        private Server getServerByPost(List<Server> servers,int port){
            for(Server s:servers){
                if(s.getPort() == port){
                    return s;
                }
            }
            return null;
        }
    
        public void setLoadBalancer(ILoadBalancer lb) {
            this.lb=lb;
    
        }
    
        public ILoadBalancer getLoadBalancer() {
            return this.lb;
        }
    
    }

*  main方法使用MyRule策略：

ConfigurationManager.getConfigInstance().setProperty(
                    "my-client.ribbon.NFLoadBalancerRuleClassName", MyRule.class.getName());

*  测试，可以看到，调用8080端口比8081端口的多：

{"id":1,"name":"小米","message":"http://localhost:8080/person"}
    {"id":1,"name":"小米","message":"http://localhost:8080/person"}
    {"id":1,"name":"小米","message":"http://localhost:8080/person"}
    {"id":1,"name":"小米","message":"http://localhost:8081/person"}
    {"id":1,"name":"小米","message":"http://localhost:8081/person"}
    {"id":1,"name":"小米","message":"http://localhost:8080/person"}
    {"id":1,"name":"小米","message":"http://localhost:8080/person"}
    {"id":1,"name":"小米","message":"http://localhost:8080/person"}
    {"id":1,"name":"小米","message":"http://localhost:8080/person"}
    {"id":1,"name":"小米","message":"http://localhost:8081/person"}

[SpringCloud_Ribbon]: https://blog.csdn.net/qq_26641781/article/details/79871101