public class TCPEchoServer {
    private static final int BUFSIZE = 32;

    /**
         * @param args
    　  */
        public static void main(String[] args) throws IOException {
            // TODO Auto-generated method stub
            // 從控制臺(tái)獲取需要監(jiān)聽的端口號(hào)
            if (args.length != 1)
                throw new IllegalArgumentException("Parameter(s):<Port>");
            // 獲取端口號(hào)
            int servPort = Integer.parseInt(args[0]);
            // 實(shí)例化一個(gè)ServerSocket對(duì)象實(shí)例
            ServerSocket servSocket = new ServerSocket(servPort);
            System.out.println(MessageFormat.format("開始啟動(dòng)監(jiān)聽扩所，端口號(hào):{0}", args[0]));

            // 初始接收數(shù)據(jù)的總字節(jié)數(shù)
            int recvMsgSize;
            // 接收數(shù)據(jù)的緩沖區(qū)
            byte[] receiveBuf = new byte[BUFSIZE];

            // 循環(huán)迭代围详，監(jiān)聽端口號(hào),處理新的連接請(qǐng)求
            while (true) {
                // 阻塞等待，每接收到一個(gè)請(qǐng)求就創(chuàng)建一個(gè)新的連接實(shí)例
                Socket clntSocket = servSocket.accept();
                // 獲取連接的客戶端的 SocketAddress
                SocketAddress clientAddress = clntSocket.getRemoteSocketAddress();
                // 打印輸出連接客戶端地址信息
                System.out.println("Handling client at" + clientAddress);
                // 從客戶端接收數(shù)據(jù)的對(duì)象
                InputStream in = clntSocket.getInputStream();
                // 向客戶端發(fā)送數(shù)據(jù)的對(duì)象
                OutputStream out = clntSocket.getOutputStream();
                // 讀取客戶端發(fā)送的數(shù)據(jù)后祖屏，再發(fā)送到客戶端
                while ((recvMsgSize = in.read(receiveBuf)) != -1) {
                    out.write(receiveBuf, 0, recvMsgSize);
                }
                // 客戶端關(guān)閉連接時(shí)助赞，關(guān)閉連接
                System.out.println(" 客戶端關(guān)閉連接");
                clntSocket.close();
            }

        }

}

import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.net.Socket;
import java.net.SocketException;

public class TCPEchoClient {
    /**
     * @param args
     * @throws IOException
     */
    public static void main(String[] args) throws IOException {
        // TODO Auto-generated method stub
        // 判斷從控制臺(tái)接受的參數(shù)是否正確
        if ((args.length < 2) || (args.length > 3))
            throw new IllegalArgumentException("Parameter(s):<Server><Word>[<Port>]]");
        // 獲取服務(wù)器地址
        String server = args[0];
        // 獲取需要發(fā)送的信息
        byte[] data = args[1].getBytes();
        // 如果有三個(gè)從參數(shù)那么就獲取發(fā)送信息的端口號(hào)，默認(rèn)端口號(hào)為8099
        int servPort = (args.length == 3) ? Integer.parseInt(args[2]) : 8099;
        // 根據(jù)服務(wù)器地址和端口號(hào)實(shí)例化一個(gè)Socket實(shí)例
        Socket socket = new Socket(server, servPort);
        System.out.println("Connected to server...sending echo string");
        // 返回此套接字的輸入流袁勺，即從服務(wù)器接受的數(shù)據(jù)對(duì)象
        InputStream in = socket.getInputStream();
        // 返回此套接字的輸出流雹食，即向服務(wù)器發(fā)送的數(shù)據(jù)對(duì)象
        OutputStream out = socket.getOutputStream();
        // 向服務(wù)器發(fā)送從控制臺(tái)接收的數(shù)據(jù)
        out.write(data);
        // 接收數(shù)據(jù)的計(jì)數(shù)器，將寫入數(shù)據(jù)的初始偏移量
        int totalBytesRcvd = 0;
        // 初始化接收數(shù)據(jù)的總字節(jié)數(shù)
        int bytesRcvd;
        while (totalBytesRcvd < data.length) {
            // 服務(wù)器關(guān)閉連接期丰，則返回 -1,read方法返回接收數(shù)據(jù)的總字節(jié)數(shù)
            if ((bytesRcvd = in.read(data, totalBytesRcvd, data.length - totalBytesRcvd)) == -1)
                throw new SocketException("與服務(wù)器的連接已關(guān)閉");
            totalBytesRcvd += bytesRcvd;
        }
        // 打印服務(wù)器發(fā)送來的數(shù)據(jù)
        System.out.println("Received:" + new String(data));
        // 關(guān)閉連接
        socket.close();

    }

}

服務(wù)端程序群叶，建立ServerSocket監(jiān)聽客戶端Socket的連接請(qǐng)求，并使用Socket獲取輸入輸出流钝荡。

public class Server{
      public static void main(String[] args){
              ServerSocket ss = new ServerSocket(3000);
               while(true){
                      Socket s= ss.accept();
                      PrintStream ps= new PrintStream (s.getOutputStream());
                      ps.println("您接收到服務(wù)器的消息");
                      ps.close();
                      s.close();
                       }
              }
}

客戶端使用socket建立與IP地址盖呼、指定端口的連接，并使用Socket獲取輸入流獲取數(shù)據(jù)化撕。

public static void main(String[] args) throws IOException{
        Socket socket=new Soket("127.0.0.1",30000);
        BufferedRead br = new BufferedReader(new InputStreamReader(socket.getInputStream()));
        String line=br.readLine();
        System.out.println("來自服務(wù)器的數(shù)據(jù)： "+line);
        br.close();
        socket.close();
}