java socket建立长连接_Java Web项目中使用Socket通信多线程 长连接的方法

很多时候在javaweb项目中我们需要用到Socket通信来实现功能，在web中使用Socket我们需要建立一个监听程序，在程序启动时，启动socket监听。我们的应用场景是在java项目中，需要外接如一个硬件设备，通过tcp通信，获取设备传上来的数据，并对数据做回应。

先看一下web的监听代码：

import javax.servlet.ServletContextEvent;

import javax.servlet.ServletContextListener;

public class AttendSocetListener implements ServletContextListener{

private SocketThread socketThread;

public void contextDestroyed(ServletContextEvent arg) {

if(null!=socketThread && !socketThread.isInterrupted())

{

socketThread.closeSocketServer();

socketThread.interrupt();

}

}

@Override

public void contextInitialized(ServletContextEvent arg) {

// TODO Auto-generated method stub

if(null==socketThread)

{

//新建线程类

socketThread=new SocketThread(null);

//启动线程

socketThread.start();

}

}

}

创建线程：

import java.io.IOException;

import .ServerSocket;

import .Socket;

import java.util.ArrayList;

import java.util.List;

public class SocketThread extends Thread

{

private ServerSocket serverSocket = null;

public SocketThread(ServerSocket serverScoket){

try {

if(null == serverSocket){

this.serverSocket = new ServerSocket();

System.out.println("socket start");

}

} catch (Exception e) {

System.out.println("SocketThread创建socket服务出错");

e.printStackTrace();

}

}

public void run(){

while(true){

try {

if(serverSocket==null){

break;

}else if(serverSocket.isClosed()){

break;

}

Socket socket = serverSocket.accept();

if(null != socket && !socket.isClosed()){

//处理接受的数据

Thread t = new Thread(new SocketOperate(socket));

t.start();

}else{

break;

}

}catch (Exception e) {

System.out.println("SocketThread创建socket服务出错");

e.printStackTrace();

}

}

}

public void closeSocketServer(){

try {

if(null!=serverSocket && !serverSocket.isClosed())

{

serverSocket.close();

}

} catch (IOException e) {

// TODO Auto-generated catch block

e.printStackTrace();

}

}

}

处理接受到的数据：

import java.io.BufferedReader;

import java.io.IOException;

import java.io.InputStreamReader;

import java.io.OutputStream;

import .Socket;

public class SocketOperate implements Runnable {

private Socket socket;

//该线程所处理的Socket所对应的输入流

BufferedReader br = null;

String str = null;

String content = null;

InputStreamReader reader=null;

public SocketOperate(Socket socket) throws IOException

{

this.socket = socket;

reader = new InputStreamReader(this.socket.getInputStream(),"utf-");

br = new BufferedReader(reader);

}

@Override

public void run()

{

try

{

// 采用循环不断从Socket中读取客户端发送过来的数据

while (true)

{

content = readFromClient();

System.out.println(content);

if (content == null)

{

break;

}

OutputStream os = socket.getOutputStream();

os.write(("RES, OK,, ,#" + "\n").getBytes("utf-"));

os.flush();

}

}

catch (IOException e)

{

e.printStackTrace();

}

}

//定义读取客户端数据的方法

private String readFromClient()

{

try

{

str = br.readLine();

return str;

}

//如果捕捉到异常，表明该Socket对应的客户端已经关闭

catch (IOException e)

{

try {

br.close();

reader.close();

socket.close();

} catch (IOException e) {

// TODO Auto-generated catch block

e.printStackTrace();

}

}

return null;

}

}

客户端代码：

package

import java.io.*;

import .*;

public class TalkClient {

public static void main(String args[]) throws UnknownHostException, IOException {

Socket socket=new Socket("...",);

PrintWriter os=new PrintWriter(socket.getOutputStream());

BufferedReader is=new BufferedReader(new InputStreamReader(socket.getInputStream()));

int i=;

while(socket.isConnected()){

os.print("BEAT,,,,.,,#"+"\n");

os.flush();

System.out.println("Client:"+i);

System.out.println("Server:"+is.readLine());

i++;

}

//继续循环

os.close(); //关闭Socket输出流

is.close(); //关闭Socket输入流

socket.close(); //关闭Socket

}

}

以上所述是小编给大家介绍的Java Web项目中使用Socket通信多线程、长连接的方法，希望对大家有所帮助！