Question

My prof. gave me this TCP/UDP example and he said it worked for him. However when I go to compile I get a deprecated API error saying readLine is not in use anymore…

How do I handle this?

Code:

import java.io.*;
import java.net.*;

public class Server{

    static  Socket clientSocket = null;
    static  ServerSocket serverSocket = null;

    // This chat server can accept up to 10 clients' connections

    static  clientThread t[] = new clientThread[10];

    public static void main(String args[]) {

    // The default port

    int port_number=2222;

    if (args.length < 1)
        {
        System.out.println("Usage: java MultiThreadChatServer \n"+
                   "Now using port number="+port_number);
        } else {
        port_number=Integer.valueOf(args[0]).intValue();
        }

        try {
        serverSocket = new ServerSocket(port_number);
        }
        catch (IOException e)
        {System.out.println(e);}

    while(true){
        try {
        clientSocket = serverSocket.accept();
        for(int i=0; i<=9; i++){
            if(t[i]==null)
            {
                (t[i] = new clientThread(clientSocket,t)).start();
                break;
            }
        }
        }
        catch (IOException e) {
        System.out.println(e);}
    }
    }
}

class clientThread extends Thread{

    DataInputStream is = null;
    PrintStream os = null;
    Socket clientSocket = null;
    clientThread t[];

    public clientThread(Socket clientSocket, clientThread[] t){
    this.clientSocket=clientSocket;
        this.t=t;
    }

    public void run()
    {
    String line;
        String name;
    try{
        is = new DataInputStream(clientSocket.getInputStream());
        os = new PrintStream(clientSocket.getOutputStream());
        os.println("Enter your name.");
        name = is.readLine();
        os.println("Hello "+name+" to our chat room.\nTo leave enter /quit in a new line");
        for(int i=0; i<=9; i++)
        if (t[i]!=null && t[i]!=this)
            t[i].os.println("*** A new user "+name+" entered the chat room !!! ***" );
        while (true) {
        line = is.readLine();
                if(line.startsWith("/quit")) break;
        for(int i=0; i<=9; i++)
            if (t[i]!=null)  t[i].os.println("<"+name+"> "+line);
        }
        for(int i=0; i<=9; i++)
        if (t[i]!=null && t[i]!=this)
            t[i].os.println("*** The user "+name+" is leaving the chat room !!! ***" );

        os.println("*** Bye "+name+" ***");

        for(int i=0; i<=9; i++)
        if (t[i]==this) t[i]=null;

        is.close();
        os.close();
        clientSocket.close();
    }
    catch(IOException e){};
    }
}

The same thing happens in the Client class.

Answer 1

I’m assuming that you would like to know what you should be using instead? The Java API document states that you should use BufferedReader instead and they even give you the codez!