基于javaweb语言的MQTT客户端
基于javaweb的MQTT客户端
本客户端使用了org.eclipse.paho.client.mqttv3-1.2.0的插件，在myeclipse上实现，并且连接了数据库，前端实现数据的发送接收，并且把接收的数据存入数据库。
MATT简介
MQTT（Message Queuing Telemetry Transport，消息队列遥测传输协议），是一种基于发布/订阅（publish/subscribe）模式的"轻量级"通讯协议，该协议构建于TCP/IP协议上，由IBM在1999年发布。MQTT最大优点在于，可以以极少的代码和有限的带宽，为连接远程设备提供实时可靠的消息服务。作为一种低开销、低带宽占用的即时通讯协议，使其在物联网、小型设备、移动应用等方面有较广泛的应用。
MQTT是一个基于客户端-服务器的消息发布/订阅传输协议。MQTT协议是轻量、简单、开放和易于实现的，这些特点使它适用范围非常广泛。在很多情况下，包括受限的环境中，如：机器与机器（M2M）通信和物联网（IoT）。其在，通过卫星链路通信传感器、偶尔拨号的医疗设备、智能家居、及一些小型化设备中已广泛使用。
首先建立两个servlet（连接前端，接收数据）
package com.example.servlet;
import java.io.IOException;
import java.io.PrintWriter;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import com.activemq.mqtt.MyMqttRecieveMessage;
public class subscribeservlet extends HttpServlet {
/**
* Destruction of the servlet.
*/
public void destroy() {
super.destroy(); // Just puts "destroy" string in log
// Put your code here
}
/**
* The doGet method of the servlet.
*
* This method is called when a form has its tag value method equals to get.
*
* @param request the request send by the client to the server
* @param response the response send by the server to the client
* @throws ServletException if an error occurred
* @throws IOException if an error occurred
*/
public void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
System.out.println("subscribeservlet");
String Topic=request.getParameter("Topic");
System.out.println (Topic);
String QOS=request.getParameter("QOS");
int Qos= Integer.parseInt(QOS);
System.out.println ( Qos);
MyMqttRecieveMessage.recieve(Topic,Qos);
}
/**
* The doPost method of the servlet.
*
* This method is called when a form has its tag value method equals to post.
*
* @param request the request send by the client to the server
* @param response the response send by the server to the client
* @throws ServletException if an error occurred
* @throws IOException if an error occurred
*/
public void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
}
/**
* Initialization of the servlet.
*
* @throws ServletException if an error occurs
*/
public void init() throws ServletException {
// Put your code here
}
}
package com.example.servlet;
import java.io.IOException;
import java.io.PrintWriter;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import org.eclipse.paho.client.mqttv3.MqttException;
import org.eclipse.paho.client.mqttv3.MqttMessage;
import org.eclipse.paho.client.mqttv3.MqttPersistenceException;
import com.activemq.mqtt.MyMqttRecieveMessage;
import com.activemq.mqtt.Server;
public class Mainservlet extends HttpServlet {
/**
* Destruction of the servlet.
*/
public void destroy() {
super.destroy(); // Just puts "destroy" string in log
// Put your code here
}
/**
* The doGet method of the servlet.
*
* This method is called when a form has its tag value method equals to get.
*
* @param request the request send by the client to the server
* @param response the response send by the server to the client
* @throws ServletException if an error occurred
* @throws IOException if an error occurred
*/
public void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
// MyMqttRecieveMessage.recieve("webServer");
System.out.println ("servlet已运行");
String Topic=request.getParameter("Topic");
System.out.println (Topic);
String QOS=request.getParameter("QOS");
int Qos= Integer.parseInt(QOS);
String Payload=request.getParameter("Payload");
System.out.println (Payload);
try {
Server server=new Server(Topic,Qos,Payload);
} catch (MqttException e) {
// TODO 自动生成的 catch 块
e.printStackTrace();
}
request.setAttribute("Topic", Topic);
request.setAttribute("QOS",QOS);
request.setAttribute("Payload",Payload);
request.getRequestDispatcher("/publishlist.jsp").forward(request,response);
}
/**
* The doPost method of the servlet.
*
* This method is called when a form has its tag value method equals to post.
*
* @param request the request send by the client to the server
* @param response the response send by the server to the client
* @throws ServletException if an error occurred
* @throws IOException if an error occurred
*/
public void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
}
/**
* Initialization of the servlet.
*
* @throws ServletException if an error occurs
*/
public void init() throws ServletException {
// Put your code here
}
}
##连接MQTT服务器代码
package com.activemq.mqtt;
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.MqttSecurityException;
import org.eclipse.paho.client.mqttv3.persist.MemoryPersistence;
//import com.wanwei.ilogger.ilogger;
public class MyMqttRecieveMessage {
//private static int QoS = 1;
private static String Host = "tcp://127.0.0.1:1883";
private static MemoryPersistence memoryPersistence = null;
private static MqttConnectOptions mqttConnectOptions = null;
private static MqttClient mqttClient = null;
public static void init(String clientId) {
mqttConnectOptions = new MqttConnectOptions();
memoryPersistence = new MemoryPersistence();
//ilogger ilogger = new ilogger("MyMqttRecieveMessage", "init");
if(null != memoryPersistence && null != clientId && null != Host) {
try {
mqttClient = new MqttClient(Host, clientId, memoryPersistence);
} catch (MqttException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}else {
//ilogger.logerr("memoryPersistence clientId Host 有空值");
}
if(null != mqttConnectOptions) {
mqttConnectOptions.setCleanSession(true);
mqttConnectOptions.setConnectionTimeout(30);
mqttConnectOptions.setKeepAliveInterval(45);
if(null != mqttClient && !mqttClient.isConnected()) {
mqttClient.setCallback(new PushCallback());
try {
mqttClient.connect();
} catch (MqttException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}else {
//ilogger.logerr("mqttClient is error");
}
}else {
// ilogger.logerr("mqttConnectOptions is null");
}
}
public static void recieve(String topic,int QoS) {
int[] Qos = {QoS};
String[] topics = {topic};
// ilogger ilogger = new ilogger("MyMqttRecieveMessage", "subTopic");
if(null != mqttClient && mqttClient.isConnected()) {
if(null!=topics && null!=Qos && topics.length>0 && Qos.length>0) {
try {
mqttClient.subscribe(topics, Qos);
System.out.print("订阅成功............");
} catch (MqttException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}else {
// ilogger.logerr("there is error");
}
}else {
init("subclient");
recieve(topic,QoS);
}
}
}
/**
* @Title: PushCallback.java
* @Package org.chisj.mqtt
* @Description: TODO
* @author chisj [email protected]
* @date 2017年4月1日
*/
package com.activemq.mqtt;
import org.eclipse.paho.client.mqttv3.IMqttDeliveryToken;
import org.eclipse.paho.client.mqttv3.MqttCallback;
import org.eclipse.paho.client.mqttv3.MqttMessage;
/**
* 发布消息的回调类
*
* 必须实现MqttCallback的接口并实现对应的相关接口方法CallBack 类将实现 MqttCallBack。
* 每个客户机标识都需要一个回调实例。在此示例中，构造函数传递客户机标识以另存为实例数据。
* 在回调中，将它用来标识已经启动了该回调的哪个实例。
* 必须在回调类中实现三个方法：
*
* public void messageArrived(MqttTopic topic, MqttMessage message)接收已经预订的发布。
*
* public void connectionLost(Throwable cause)在断开连接时调用。
*
* public void deliveryComplete(MqttDeliveryToken token))
* 接收到已经发布的 QoS 1 或 QoS 2 消息的传递令牌时调用。
* 由 MqttClient.connect 激活此回调。
*
*/
public class PushCallback implements MqttCallback {
public void connectionLost(Throwable cause) {
// 连接丢失后，一般在这里面进行重连
System.out.println("连接断开，可以做重连");
}
public void deliveryComplete(IMqttDeliveryToken token) {
System.out.println("deliveryComplete---------" + token.isComplete());
}
public void messageArrived(String topic, MqttMessage message) throws Exception {
// subscribe后得到的消息会执行到这里面
System.out.println("接收消息主题 : " + topic);
System.out.println("接收消息Qos : " + message.getQos());
System.out.println("接收消息内容 : " + new String(message.getPayload()));
}
}
/**
* @Title: Server.java
* @Package org.chisj.mqtt
* @Description: TODO
*
*
*/
package com.activemq.mqtt;
import org.eclipse.paho.client.mqttv3.MqttClient;
import org.eclipse.paho.client.mqttv3.MqttConnectOptions;
import org.eclipse.paho.client.mqttv3.MqttDeliveryToken;
import org.eclipse.paho.client.mqttv3.MqttException;
import org.eclipse.paho.client.mqttv3.MqttMessage;
import org.eclipse.paho.client.mqttv3.MqttPersistenceException;
import org.eclipse.paho.client.mqttv3.MqttTopic;
import org.eclipse.paho.client.mqttv3.persist.MemoryPersistence;
/**
* ClassName: Server
* @Description: TODO
* @author
* @date
*/
//发布
public class Server {
public static final String HOST = "tcp://127.0.0.1:1883";
public static String TOPIC ;
// public static final String TOPIC125 = "toclient/125";
private static final String clientid = "server";
private MqttClient client;
private MqttTopic topic;
// private MqttTopic topic125;
private String userName = "admin";
private String passWord = "public";
private MqttMessage message;
public Server(String topic1 ,int id,String payload) throws MqttException {
this.TOPIC=topic1;
client = new MqttClient(HOST, clientid, new MemoryPersistence());
connect();
message = new MqttMessage();
message.setQos(id);
message.setRetained(true);
message.setPayload(payload.getBytes());
publish(topic ,message);
// MemoryPersistence设置clientid的保存形式，默认为以内存保存
}
private void connect() {
MqttConnectOptions options = new MqttConnectOptions();
options.setCleanSession(false);
options.setUserName(userName);
options.setPassword(passWord.toCharArray());
// 设置超时时间
options.setConnectionTimeout(10);
// 设置会话心跳时间
options.setKeepAliveInterval(20);
try {
client.setCallback(new PushCallback());
client.connect(options);
topic = client.getTopic(TOPIC);
// topic125 = client.getTopic(TOPIC125);
} catch (Exception e) {
e.printStackTrace();
}
}
public void publish(MqttTopic topic , MqttMessage message) throws MqttPersistenceException,
MqttException {
MqttDeliveryToken token = topic.publish(message);
token.waitForCompletion();
System.out.println("message is published completely! "
+ token.isComplete());
}
// public static void publicmessage(String topic,String message,int Qos) throws MqttException {
// Server server = new Server();
// server.message = new MqttMessage();
// server.message.setQos(2);
// server.message.setRetained(true);
// server.message.setPayload("给客户端124推送的信息".getBytes());
// server.publish(server.topic , server.message);
// System.out.println(server.message.isRetained() + "------ratained状态");
// }
}
只需要创建jsp前台页面，发送到servlet则可调用其他几个类，并且我把消息封装成类，插入数据库。