Java连接MQTT服务-wss方式

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说明：前面介绍的tcp、ws方式适合Java程序在局域网内使用，不涉及到安全问题。但由于Android手机APP需要通过websocket方式来连接,就必须考虑安全性问题了，这时候就采用了wss+CA证书方式进行认证，而且在数据传输中也是加密的。大致与ws方式相同，只不过是加了证书。

1、Java代码

 package com.mao.mqtt;

 import java.io.FileInputStream;
 import java.security.KeyStore;
 import java.security.cert.CertificateFactory;
 import java.security.cert.X509Certificate;
 import java.text.SimpleDateFormat;
 import java.util.Date;

 import javax.net.ssl.SSLContext;
 import javax.net.ssl.SSLSocketFactory;
 import javax.net.ssl.TrustManagerFactory;

 import org.eclipse.paho.client.mqttv3.IMqttDeliveryToken;
 import org.eclipse.paho.client.mqttv3.MqttCallback;
 import org.eclipse.paho.client.mqttv3.MqttClient;
 import org.eclipse.paho.client.mqttv3.MqttConnectOptions;
 import org.eclipse.paho.client.mqttv3.MqttException;
 import org.eclipse.paho.client.mqttv3.MqttMessage;
 import org.eclipse.paho.client.mqttv3.MqttTopic;

 /**
  *
  * 功能描述：MQTT测试
  * 创建人： mao2080@sina.com
  * 创建时间：2017年7月4日 下午5:08:59
  * 修改人： mao2080@sina.com
  * 修改时间：2017年7月4日 下午5:08:59
  */
 public class MQTTTest_wss {

     /**MQTT服务端ip及端口*/
     private static String host = "wss://ip:443";

     /**账号*/
     private static String username = "li2080";

     /**密码*/
     private static String password = "123";

     /**订阅的主题*/
     private static String subTopic = "a/b/c";

     /**clientID*/
     private static String clientId = "li2080";

     /**发布的主题*/
     private static String pubTopic = "a/b/c";

     /**MQTT-Client*/
     private static MqttClient client;

     /**证书路径*/
     private static String caPath = "E:\\mqtt-demo\\certfile\\CA.crt";

     /**
      * @throws InterruptedException
      * @throws MqttException */
     public static void main(String[] args) throws InterruptedException, MqttException {

         // 订阅消息的方法
         subscribe();
 //
         publish();
     }

     /**
      *
      * 描述：订阅信息
      * @author mao2080@sina.com
      * @created 2017年7月4日 下午4:53:47
      * @since
      * @return
      */
     public static void subscribe() {
         try {
             // 创建MqttClient
             MQTTTest_wss.getClient().setCallback(new MqttCallback() {

                 public void connectionLost(Throwable arg0) {

                 }

                 public void messageArrived(String topic, MqttMessage message) throws Exception {
                     System.out.println("MQTT Rece:" + message.toString());
                 }

                 public void deliveryComplete(IMqttDeliveryToken token) {

                 }

             });
             MQTTTest_wss.getClient().subscribe(subTopic, 0);
             System.out.println("连接状态:" + client.isConnected());
         } catch (Exception e) {
             e.printStackTrace();
         }
     }

     /**
      *
      * 描述：获取MqttClient
      * @author mao2080@sina.com
      * @created 2017年7月6日 上午9:56:37
      * @since
      * @return
      * @throws MqttException
      */
     public static MqttClient getClient() throws MqttException{
         try {
             if(client == null){
                 client = new MqttClient(host, clientId);
                 MqttConnectOptions conOptions = new MqttConnectOptions();
                 conOptions.setUserName(username);
                 conOptions.setPassword(password.toCharArray());
                 conOptions.setCleanSession(true);
                 conOptions.setSocketFactory(getSSLSocktet(caPath));
                 client.connect(conOptions);
             }
             if(!client.isConnected()){
                 client.reconnect();
             }
         } catch (Exception e) {
             e.printStackTrace();
         }
         return client;
     }

     /**
      *
      * 描述：发布信息
      * @author mao2080@sina.com
      * @throws MqttException
      * @created 2017年7月4日 下午4:53:32
      * @since
      */
     public static void publish() throws MqttException {
         SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
         String sendMsg = "{time:"+sdf.format(new Date())+", content:"+com.lds.iot.common.util.UUIDUtil.getLowerLetterNumber(15)+", from: java console}";
         try {
             MqttTopic topic = MQTTTest_wss.getClient().getTopic(pubTopic);
             MqttMessage message = new MqttMessage(sendMsg.getBytes());
             message.setQos(0);
             topic.publish(message);
             System.out.println("MQTT Send:" + sendMsg);
         } catch (Exception e) {
             e.printStackTrace();
         }
     }

     /**
      * 获取SSLSocketFactory
      * @param caPath
      * @return
      * @throws Exception
      */
     public static SSLSocketFactory getSSLSocktet(String caPath) throws Exception {
         CertificateFactory cAf = CertificateFactory.getInstance("X.509");
         FileInputStream caIn = new FileInputStream(caPath);
         X509Certificate ca = (X509Certificate) cAf.generateCertificate(caIn);
         KeyStore caks = KeyStore.getInstance(KeyStore.getDefaultType());
         caks.load(null, null);
         caks.setCertificateEntry("ca-certificate", ca);
         TrustManagerFactory tmf = TrustManagerFactory.getInstance(TrustManagerFactory.getDefaultAlgorithm());
         tmf.init(caks);
         caIn.close();
         SSLContext context = SSLContext.getInstance("TLSv1");
         context.init(null, tmf.getTrustManagers(), null);
         return context.getSocketFactory();
     }

 }

2、Maven配置

 <dependency>
       <groupId>org.eclipse.paho</groupId>
       <artifactId>org.eclipse.paho.client.mqttv3</artifactId>
       <version>1.2.0</version>
 </dependency>

3、服务端配置

请参考另一篇blog：http://www.cnblogs.com/mao2080/p/7772893.html

4、运行效果