EchoServer.java Source code

Introduction

Here is the source code for EchoServer.java

Source

/*
   This program is a part of the companion code for Core Java 8th ed.
   (http://horstmann.com/corejava)
    
   This program is free software: you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation, either version 3 of the License, or
   (at your option) any later version.
    
   This program is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License for more details.
    
   You should have received a copy of the GNU General Public License
   along with this program.  If not, see <http://www.gnu.org/licenses/>.
*/

import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.io.PrintWriter;
import java.net.ServerSocket;
import java.net.Socket;
import java.util.Scanner;

/**
 * This program implements a simple server that listens to port 8189 and echoes back all client
 * input.
 * @version 1.20 2004-08-03
 * @author Cay Horstmann
 */
public class EchoServer {
    public static void main(String[] args) {
        try {
            // establish server socket
            ServerSocket s = new ServerSocket(8189);

            // wait for client connection
            Socket incoming = s.accept();
            try {
                InputStream inStream = incoming.getInputStream();
                OutputStream outStream = incoming.getOutputStream();

                Scanner in = new Scanner(inStream);
                PrintWriter out = new PrintWriter(outStream, true /* autoFlush */);

                out.println("Hello! Enter BYE to exit.");

                // echo client input
                boolean done = false;
                while (!done && in.hasNextLine()) {
                    String line = in.nextLine();
                    out.println("Echo: " + line);
                    if (line.trim().equals("BYE"))
                        done = true;
                }
            } finally {
                incoming.close();
            }
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}