Server2.java

import java.io.*;
import java.net.*;
 public class Server2 {
    public static void main(String args[]) {
int port = 6789;
Server2 server = new Server2( port );
server.startServer();
    }

    ServerSocket echoServer = null;
    Socket clientSocket = null;
    int numConnections = 0;
    int port;
    public Server2( int port ) {
this.port = port;
    }

    public void stopServer() {
System.out.println( "Server cleaning up." );
System.exit(0);
    }

    public void startServer() {

        try {
    echoServer = new ServerSocket(port);
        }
        catch (IOException e) {
    System.out.println(e);
        } 
System.out.println( "Server is started and is waiting for connections." );
System.out.println( "With multi-threading, multiple connections are allowed." );
System.out.println( "Any client can send -1 to stop the server." );

while ( true ) {
    try {
clientSocket = echoServer.accept();
numConnections ++;
Server2Connection oneconnection = new Server2Connection(clientSocket, numConnections, this);
new Thread(oneconnection).start();
    } 
    catch (IOException e) {
System.out.println(e);
    }
}
    }
}
class Server2Connection implements Runnable {
    BufferedReader is;
    PrintStream os;
    Socket clientSocket;
    int id;
    Server2 server;
    public Server2Connection(Socket clientSocket, int id, Server2 server) {
this.clientSocket = clientSocket;
this.id = id;
this.server = server;
System.out.println( "Connection " + id + " established with: " + clientSocket );
try {
    is = new BufferedReader(new InputStreamReader(clientSocket.getInputStream()));
    os = new PrintStream(clientSocket.getOutputStream());
} catch (IOException e) {
    System.out.println(e);
}
    }
    public void run() {
        String line;
try {
    boolean serverStop = false;

            while (true) {
                line = is.readLine();
System.out.println( "Received " + line + " from Connection " + id + "." );
                int n = Integer.parseInt(line);
if ( n == -1 ) {
    serverStop = true;
    break;
}
if ( n == 0 ) break;
                os.println("" + n*n );
            }

    System.out.println( "Connection " + id + " closed." );
            is.close();
            os.close();
            clientSocket.close();

    if ( serverStop ) server.stopServer();
} catch (IOException e) {
    System.out.println(e);
}
    }
}

SHARE SHARE SHARE