The Java Web project USES the Socket communication multithreaded long connected method

Many times in the javaweb project we need to use Socket communication to achieve the function. In the web project we need to use Socket to set up a listener. When the program starts, we need to start socket listener. Our application scenario is in the java project, which requires an external hardware device, such as a device, to communicate through tcp, obtain the data transmitted by the device, and respond to the data.

Take a look at the listening code of web:

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) 
{ 
// New thread class  
socketThread=new SocketThread(null); 
// Starting a thread  
socketThread.start(); 
} 
} 
}

Create thread:

import java.io.IOException;
import java.net.ServerSocket;
import java.net.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 create socket Service error "); 
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()){ 
// Process the received data  
Thread t = new Thread(new SocketOperate(socket)); 
t.start(); 
}else{
break;
}
}catch (Exception e) { 
System.out.println("SocketThread create socket Service error "); 
e.printStackTrace(); 
} 
} 
} 
public void closeSocketServer(){ 
try { 
if(null!=serverSocket && !serverSocket.isClosed()) 
{ 
serverSocket.close(); 
} 
} catch (IOException e) { 
// TODO Auto-generated catch block 
e.printStackTrace(); 
} 
} 
}

Processing received data:

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.OutputStream;
import java.net.Socket;
public class SocketOperate implements Runnable { 
private Socket socket; 
// What the thread handles Socket The corresponding input stream  
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 
{ 
//  Use a continuous loop from Socket To read the data sent by the client  
while (true) 
{ 
content = readFromClient(); 
System.out.println(content);
if (content == null) 
{ 
break; 
} 
OutputStream os = socket.getOutputStream(); 
os.write(("RES, OK,< As a , Xiao Ming >, ,#" + "\n").getBytes("utf-")); 
os.flush();
} 
} 
catch (IOException e) 
{ 
e.printStackTrace(); 
} 
} 
// Defines a way to read client data  
private String readFromClient() 
{ 
try 
{ 
str = br.readLine(); 
return str; 
} 
// If an exception is caught, it should be Socket The corresponding client has been closed  
catch (IOException e) 
{ 
try {
br.close();
reader.close();
socket.close();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} 
} 
return null; 
} 
}

Client code:

package
import java.io.*;
import java.net.*;
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++;
} 
// Continue to cycle 
os.close(); // Shut down Socket The output stream 
is.close(); // Shut down Socket The input stream 
socket.close(); // Shut down Socket
}
}

The above is the site to introduce you Java Web project using Socket communication multi-threaded, long connection method, I hope to help you!