02--Java Socket编程--IO方式

一、基础知识

1. TCP状态转换知识，可参考：

2. 数据传输

package com.yyn.io.net;

import java.io.BufferedOutputStream;
import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.FileOutputStream;
import java.io.FileWriter;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.OutputStream;
import java.io.OutputStreamWriter;
import java.io.PrintWriter;
import java.net.Socket;
import java.net.UnknownHostException;
import java.util.Iterator;
import java.util.stream.Stream;

public class MultiThreadServerClient {

public static final int PORT = 12002;

public static void main(String[] args) throws UnknownHostException, IOException {
// TODO Auto-generated method stub
Socket socket = new Socket("127.0.0.1",PORT);
// in stream from console
InputStreamReader isr = new InputStreamReader(System.in,"UTF-8");
BufferedReader in = new BufferedReader(isr);
// out stream from socket
OutputStreamWriter osw =
new OutputStreamWriter(new BufferedOutputStream(socket.getOutputStream()), "UTF-8");
PrintWriter out = new PrintWriter(osw);

String command = null;
while(true){
System.out.println("#######################");
command = in.readLine();
if (command == null) {
socket.shutdownInput();
break;
}
command = command.trim().toUpperCase();
if (command.equals("EXIT")) {
socket.shutdownInput();
break;
}
out.println(command); //必须用println方法，不能用write，否则服务端无法获取数据，会堵塞
out.flush();
System.out.println("data send to server:"+command);
}
}

}

3. 服务器一次向多个客户端发送信息