socket available 方法请教

Question

package com.error;

import java.io.IOException;
import java.io.InputStream;
import java.io.PushbackInputStream;
import java.net.InetSocketAddress;
import java.net.Socket;

public class testclient {

	private Socket socket;
	private InputStream in ;
	
	//private PushbackInputStream pin ;
	private boolean isRead = false;
	
	private byte[] data = new byte[1024 * 10 * 10];
	
	private long notDataTime = 1000 * 3;
	
	private long time = 0;
	void startClient(){
		while(true){
			if(!validConnection(socket)){
				createConnection();
				if(validConnection(socket)){
					isRead = true;
				}
			}
			if(isRead){
				try {
					/*
					 * 
					 * 正确读取
					 * 
					 * int c = (int) pin.read();
					if(c < 0){
						continue;
					}
					pin.unread(c);
					int len = pin.available();
					if(len> 0){
						int temlen = pin.read(data,0,len);
						System.out.println("收到服务端数据:" + new String(data,0,temlen));
					}else{*/
					/**获取输入流中的有效字节 **/
					int len = in.available();
					if(len> 0){
						int temlen = in.read(data,0,len);
						System.out.println("收到服务端数据:" + new String(data,0,temlen));
					}else{
						if(time == 0){
							time  = System.currentTimeMillis();
						}
						long currentTime = System.currentTimeMillis();
						if((currentTime - time ) > notDataTime){
							System.out.println("3s 没有收到数据，断开连接");
							shutdown();
							time = 0;
						}
					}
				} catch (IOException e) {
					e.printStackTrace();
					shutdown();
					time = 0;
				}
			}
			
		}
	}
	void createConnection(){
		
		socket = new Socket();
		try {
			socket.connect(new InetSocketAddress("127.0.0.1",10011));
			System.out.println("连接服务端成功!");
			in = socket.getInputStream();
		//	pin = new PushbackInputStream(in);
		} catch (IOException e) {
			e.printStackTrace();
		}
	}
	
	boolean validConnection(Socket socket){
		
		return (socket != null && socket.isBound() && socket.isConnected());
	}
	
	void shutdown(){
		if(socket !=null){
			try {
				socket.close();
				socket = null;
			} catch (IOException e) {
				// TODO Auto-generated catch block
				e.printStackTrace();
			}
		}
		isRead = false;
	}
	
	public static void main(String[] args) {
		new testclient().startClient();
	}
}




package com.error;

import java.io.IOException;
import java.io.OutputStream;
import java.net.InetSocketAddress;
import java.net.ServerSocket;
import java.net.Socket;
import java.util.Timer;
import java.util.TimerTask;

public class testserver {
	
	private Socket socket;
	private OutputStream out ;
	void createserver(){
		
		try {
			ServerSocket server = new ServerSocket();
			server.bind(new InetSocketAddress("127.0.0.1",10011));
			System.out.println("start server.");
			socket = server.accept();
			System.out.println("新连接到到达!");
			out = socket.getOutputStream();
			
			Timer timer = new Timer();
			timer.scheduleAtFixedRate(new TimerTask() {
				int i = 0;
				@Override
				public void run() {
					
					try {
						if(i < 2 || i > 5){
							out.write(("发送给客户端数据 " + i ).getBytes());
							out.flush();
						}else{
							System.out.println("不发送数据 " + i);
						}
					} catch (IOException e) {
						System.out.println("发送数据异常，断开客户端连接!");
						e.printStackTrace();
						
					}
					i++;
					
				}
			}, 1000, 1000);
			
		} catch (IOException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
		
	}
	
	void shutdown(){
		if(socket !=null){
			try {
				socket.close();
				socket = null;
			} catch (IOException e) {
				// TODO Auto-generated catch block
				e.printStackTrace();
			}
		}
		if( out != null){
			try {
				out.close();
				out = null;
			} catch (IOException e) {
				// TODO Auto-generated catch block
				e.printStackTrace();
			}
		}
	}
	
	public static void main(String[] args) {
		new testserver().createserver();
	}

}

客户端连接服务端，服务端开始发送数据，如果客户端3s没有收到数据，那么中断连接，然后再次尝试重新建立连接。

问题是：

 当客户端3s没有数据中断连接后，in.available方法返回永远是0 了。

Answer 1

永远是零是什么意思?你shutdown之后重新connect还是零?