add ribbon example

pom.xml

@@ -18,6 +18,11 @@
  </properties>
  <dependencyManagement>
  <dependencies>
+ <dependency>
+ <groupId>com.netflix.ribbon</groupId>
+ <artifactId>ribbon</artifactId>
+ <version>2.2.2</version>
+ </dependency>
  <dependency>
  <groupId>junit</groupId>
  <artifactId>junit</artifactId>

spring/learn-ribbon/pom.xml

@@ -0,0 +1,26 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project xmlns="http:https://maven.apache.org/POM/4.0.0"
+ xmlns:xsi="http:https://www.w3.org/2001/XMLSchema-instance"
+ xsi:schemaLocation="http:https://maven.apache.org/POM/4.0.0 http:https://maven.apache.org/xsd/maven-4.0.0.xsd">
+ <modelVersion>4.0.0</modelVersion>
+ <parent>
+ <artifactId>daydayup</artifactId>
+ <groupId>com.github.landyking</groupId>
+ <version>1.0-SNAPSHOT</version>
+ <relativePath>../../</relativePath>
+ </parent>
+ <groupId>com.github.landyking</groupId>
+ <artifactId>learn-ribbon</artifactId>
+ <version>1.0-SNAPSHOT</version>
+
+ <dependencies>
+ <dependency>
+ <groupId>com.netflix.ribbon</groupId>
+ <artifactId>ribbon</artifactId>
+ </dependency>
+ <dependency>
+ <groupId>junit</groupId>
+ <artifactId>junit</artifactId>
+ </dependency>
+ </dependencies>
+</project>

spring/learn-ribbon/src/test/java/com/github/landyking/learn/ribbon/URLConnectionLoadBalancer.java

@@ -0,0 +1,70 @@
+package com.github.landyking.learn.ribbon;
+
+import java.net.HttpURLConnection;
+import java.net.MalformedURLException;
+import java.net.URL;
+import java.util.List;
+
+import rx.Observable;
+
+import com.google.common.collect.Lists;
+import com.netflix.client.DefaultLoadBalancerRetryHandler;
+import com.netflix.client.RetryHandler;
+import com.netflix.loadbalancer.BaseLoadBalancer;
+import com.netflix.loadbalancer.ILoadBalancer;
+import com.netflix.loadbalancer.LoadBalancerBuilder;
+import com.netflix.loadbalancer.LoadBalancerStats;
+import com.netflix.loadbalancer.Server;
+import com.netflix.loadbalancer.reactive.LoadBalancerCommand;
+import com.netflix.loadbalancer.reactive.ServerOperation;
+
+/**
+ *
+ * @author Allen Wang
+ *
+ */
+public class URLConnectionLoadBalancer {
+
+ private final ILoadBalancer loadBalancer;
+ // retry handler that does not retry on same server, but on a different server
+ private final RetryHandler retryHandler = new DefaultLoadBalancerRetryHandler(0, 1, true);
+
+ public URLConnectionLoadBalancer(List<Server> serverList) {
+ loadBalancer = LoadBalancerBuilder.newBuilder().buildFixedServerListLoadBalancer(serverList);
+ }
+
+ public String call(final String path) throws Exception {
+ return LoadBalancerCommand.<String>builder()
+ .withLoadBalancer(loadBalancer)
+ .build()
+ .submit(new ServerOperation<String>() {
+ @Override
+ public Observable<String> call(Server server) {
+ URL url;
+ try {
+ url = new URL("http:https://" + server.getHost() + ":" + server.getPort() + path);
+ HttpURLConnection conn = (HttpURLConnection) url.openConnection();
+ return Observable.just(conn.getResponseMessage());
+ } catch (Exception e) {
+ return Observable.error(e);
+ }
+ }
+ }).toBlocking().first();
+ }
+
+ public LoadBalancerStats getLoadBalancerStats() {
+ return ((BaseLoadBalancer) loadBalancer).getLoadBalancerStats();
+ }
+
+ public static void main(String[] args) throws Exception {
+ URLConnectionLoadBalancer urlLoadBalancer = new URLConnectionLoadBalancer(Lists.newArrayList(
+ new Server("www.163.com", 80),
+ new Server("www.baidu.com", 80),
+ new Server("www.qq.com", 80)));
+ for (int i = 0; i < 6; i++) {
+ System.out.println(urlLoadBalancer.call("/"));
+ }
+ System.out.println("=== Load balancer stats ===");
+ System.out.println(urlLoadBalancer.getLoadBalancerStats());
+ }
+}