package com.asiaInfo.caozg.ch_01;import java.io.*;
import java.net.Socket;/*** @Authgor: gosaint* @Description:* @Date Created in 21:31 2018/1/7* @Modified By:客户端代码*/
public class EchoClient {// 本机的IP地址private String host = "localhost";// 本机的端口号private int port = 8000;// socket 对象private Socket socket;// 构造器初始化Socket对象public EchoClient() throws IOException {socket = new Socket(host, port);}// 测试方法public static void main(String args[]) throws IOException {new EchoClient().talk();}private PrintWriter getWriter(Socket socket) throws IOException {OutputStream socketOut = socket.getOutputStream();return new PrintWriter(socketOut, true);}private BufferedReader getReader(Socket socket) throws IOException {InputStream socketIn = socket.getInputStream();return new BufferedReader(new InputStreamReader(socketIn));}public void talk() throws IOException {try {// 从socket读取数据BufferedReader br = getReader(socket);// 向socket写入数据PrintWriter pw = getWriter(socket);// 把控制台输入的数据转换为字符流，然后读取BufferedReader localReader = new BufferedReader(new InputStreamReader(System.in));String msg = null;while ((msg = localReader.readLine()) != null) {// 将读取的数据写出的输出流（打印流）
                pw.println(msg);System.out.println(br.readLine());if (msg.equals("bye"))break;}} catch (IOException e) {e.printStackTrace();} finally {try {socket.close();} catch (IOException e) {e.printStackTrace();}}}
}

package com.asiaInfo.caozg.ch_01;import java.io.*;
import java.net.*;public class EchoServer {private int port = 8000;private ServerSocket serverSocket;public EchoServer() throws IOException {serverSocket = new ServerSocket(port);System.out.println("服务器启动");}public String echo(String msg) {return "echo:" + msg;}private PrintWriter getWriter(Socket socket) throws IOException {OutputStream socketOut = socket.getOutputStream();return new PrintWriter(socketOut, true);}private BufferedReader getReader(Socket socket) throws IOException {InputStream socketIn = socket.getInputStream();return new BufferedReader(new InputStreamReader(socketIn));}public void service() {while (true) {Socket socket = null;try {socket = serverSocket.accept();  //等待客户连接System.out.println("New connection accepted "+ socket.getInetAddress() + ":" + socket.getPort());// 从socket获取输入流字符，阅读消息BufferedReader br = getReader(socket);// 向socket写出数据PrintWriter pw = getWriter(socket);String msg = null;// 阅读消息while ((msg = br.readLine()) != null) {System.out.println(msg);// 写出消息
                    pw.println(echo(msg));if (msg.equals("bye")) //如果客户发送的消息为“bye”，就结束通信break;}} catch (IOException e) {e.printStackTrace();} finally {try {if (socket != null) socket.close();  //断开连接} catch (IOException e) {e.printStackTrace();}}}}public static void main(String args[]) throws IOException {new EchoServer().service();}
}

4 Socket用法

（1）：连接本机1-1024端口

该Demo的作用是练习Socket对象的创建。我们通过连接端口，表明该端口被服务器监听了。在这个区间的大多端口已经被占用，但是我们还是可以连接没有被占用的端口。