Socket 简单的相互通讯

TCPEchoServer

package com.mz.xx.code.atest;

import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.net.ServerSocket;
import java.net.Socket;
import java.net.SocketAddress;

public class TCPEchoServer {
    
    private static final int BUFSIZE = 32;
    
    public static void main(String[] args) throws IOException{
            
            int servPort = 7788;
        
            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 out = clntSock.getOutputStream();
                
                while((recvMsgSize = in.read(receiveBuf))!=-1){
                    System.out.println("IN...");
                    out.write(receiveBuf,0,recvMsgSize);
                    out.flush();
                    System.out.println("Sended:"+new String(receiveBuf)+"\t"+recvMsgSize);
                }
                clntSock.close();
            }
    
    }

}

TCPEchoClient

package com.mz.xx.code.atest;

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

public class TCPEchoClient {

    public static void main(String[] args) throws UnknownHostException,
            IOException {
        String server = "localhost";
        byte[] data = "abcdefghijklmnopqrstuvwxyz_ABCDEFGHIJKLMNOPQRSTUVWXYZ  ".getBytes();
        
        int servPort = 7788;

        Socket socket = new Socket(server, servPort);
        System.out.println("Connected to server...sending echo string");

        InputStream in = socket.getInputStream();
        OutputStream out = socket.getOutputStream();

        out.write(data);

        int totalBytesRcvd = 0;
        int bytesRcvd;

        byte[] dataArray = new byte[data.length];
        
        
        /**
         * 以前学习socket,对于消息的读取也就用一个read().最近在学一本socke编程的书籍,书中这样写到:
         * TCP协议并不能确定在read() 和 write() 方法中所发送信息的界限,也就是说,虽然我们只用勒一个
         * write()方法来发送回馈字符串,回馈服务器也可以从多个块中接受该信息。即使回馈字符串在服务器
         * 上存在于一个块中，在返回的时候，也可能被TCP协议分割成多个部分。对于初学者来说，最常见的错误
         * 就是认为由一个write()方法发送的数据总是会由一个read()方法来接受。
         * 
         */
        while (totalBytesRcvd < dataArray.length) {
            if ((bytesRcvd = in.read(dataArray, totalBytesRcvd, data.length
                    - totalBytesRcvd)) == -1)
                throw new SocketException("Connection closed prematurely");
            totalBytesRcvd += bytesRcvd;
        }//data array is full
        System.out.println("Received: " + new String(dataArray)+"\t"+dataArray.length);
        socket.close();
    }
}

Java TCP/IP Socket 源码: