简单的Echo服务器和客户端
package tcp;import java.io.BufferedReader;import java.io.BufferedWriter;import java.io.IOException;import java.io.InputStreamReader;import java.io.OutputStreamWriter;import java.io.PrintWriter;import java.net.ServerSocket;import java.net.Socket;public class EchoServer { /** * @param args */ public static void main(String[] args) { // TODO Auto-generated method stub ServerSocket serverSocekt = null; Socket socket = null; BufferedReader inBuffer = null; PrintWriter out = null; try { serverSocekt = new ServerSocket(12); System.out.println("The server is start:" + serverSocekt); socket = serverSocekt.accept(); System.out.println("Accpet the Client:" + socket); inBuffer = new BufferedReader(new InputStreamReader(socket.getInputStream())); out = new PrintWriter(new BufferedWriter(new OutputStreamWriter(socket.getOutputStream())), true); while(true) { String instr = inBuffer.readLine(); System.out.println("In Server reveived the info:" + instr); if (instr.equals("bye")) { break; } out.println(instr); } } catch (IOException e) { e.printStackTrace(); } finally { try { if (socket != null) { socket.close(); } if (inBuffer != null) { inBuffer.close(); } if (out != null) { out.close(); } } catch (IOException e) { e.printStackTrace(); } } }}package tcp;import java.io.BufferedReader;import java.io.BufferedWriter;import java.io.IOException;import java.io.InputStreamReader;import java.io.OutputStreamWriter;import java.io.PrintWriter;import java.net.NetworkInterface;import java.net.Socket;import java.net.UnknownHostException;public class EchoClient { /** * @param args */ public static void main(String[] args) { // TODO Auto-generated method stub String hostname = "localhost"; if (args.length > 0) { hostname = args[0]; } PrintWriter out = null; BufferedReader networkIn = null; Socket theSocket; try { System.out.println(hostname); theSocket = new Socket(hostname, 12); networkIn = new BufferedReader(new InputStreamReader(theSocket.getInputStream())); BufferedReader userIn = new BufferedReader(new InputStreamReader(System.in)); out = new PrintWriter(new BufferedWriter(new OutputStreamWriter(theSocket.getOutputStream())), true); System.out.println("connect to echo server."); while(true) { String theLine = userIn.readLine(); if (theLine.equals(".")) { break; } out.println(theLine); out.flush(); System.out.println(networkIn.readLine()); } } catch (UnknownHostException e) { // TODO Auto-generated catch block System.err.println(e); } catch (IOException e) { // TODO Auto-generated catch block e.printStackTrace(); } finally { if (networkIn != null) { try { networkIn.close(); } catch (IOException e) { // TODO Auto-generated catch block e.printStackTrace(); } } if (out != null) { out.close(); } } }}