java socket客户端服务端（简单示例）

客户端程序

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

public class TCPEchoClient{
 public static void main(String[] args) throws IOException{
  if((args.length < 2) || (args.length > 3))
      throw new IllegalArgumentException("Parameter(s): <Server> <Word> [Port]");
     
  String server = args[0];
  byte[] data = args[1].getBytes();
  
  int servPort = (args.length == 3) ? Integer.parseInt(args[2]) : 7;
  
  Socket socket = new Socket(server,servPort);
  System.out.println("Connected to server ... sending echo string");
  
  InputStream in = socket.getInputStream();
  OutputStream ut = socket.getOutputStream();
  out.write(data);
  
  int totalBytesRcvd = 0;
  int bytesRcvd;
  while(totalBytesRcvd < data.length) {
   if((bytesRcvd = in.read(data, totalBytesRcvd,data.length - totalBytesRcvd)) == -1)
       throw new SocketException("Connection closed premaurely");
   totalBytesRcvd += bytesRcvd;
  }
  
  System.out.println("Received: " + new String(data));
  
  socket.close();
 }
}

服务端程序

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

public class TCPEchoServer {
 private static final int BUFSIZE = 32;
 
 public static void main(String[] args) throws IOException {
  if(args.length != 1)
      throw new IllegalArgumentException("Parameter(s): <Port>");
  
  int servPort = Integer.parseInt(args[0]);
  ServerSocket servSock = new ServerSocket(servPort);
  
  int recvMsgSize;
  byte[] receiveBuf = new byte[BUFSIZE];
  
  while(true) {
   Socket clntSock = servSock.accept();
   
   SocketAddress clientAddress = clntSock.getRemoteSocketAddress();
   System.out.println("Handling client at " + clientAddress);
   
   InputStream in = clntSock.getInputStream();
   OutputStream ut = clntSock.getOutputStream();
   
   while((recvMsgSize = in.read(receiveBuf)) != -1){
    out.write(receiveBuf, 0, recvMsgSize);
    System.out.println(new String(receiveBuf));
   }
   clntSock.close();
  }
 }
}

首先运行服务端

E:\socket>java TCPEchoServer 9080

然后运行客户端，向服务端发送test字符串，服务端再发回

E:\socket>java TCPEchoClient 192.168.1.100  test 9080
Connected to server ... sending echo string
Received: test

服务端的情况

E:\socket>java TCPEchoServer 9080
Handling client at /192.168.1.100:14479
test