echoserver.java

java应用开发详解

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

public class EchoServer 
{
    public static void main(String[] args) throws IOException 
    {	
        ServerSocket serverSocket = null;
        PrintWriter out = null;
        BufferedReader in = null;

        try 
        {
            serverSocket = new ServerSocket(1111);    
        } 
        catch (IOException e) 
        {
            System.err.println("Could not listen on port: 1111.");
            System.exit(1);
        } 

	Socket incoming = null;
        while(true)
        {
            incoming = serverSocket.accept();
            out = new PrintWriter(incoming.getOutputStream(), true);
            in = new BufferedReader(new InputStreamReader(incoming.getInputStream()));
            out.println("Hello! . . . ");
            out.println("Enter BYE to exit");
            out.flush();
            while(true)
            {
            	String str = in.readLine();
            	if(str == null)
            	{
            		break; //client closed connection
            	}
            	else
            	{
            		out.println("Echo: "+str);
            		out.flush();
            		if(str.trim().equalsIgnoreCase("BYE"))
            		  break;
            	}
            }
            
            out.close();
	    in.close();
	
	    incoming.close(); 
            serverSocket.close();
        } 
        
    }
}