求助java中Socket问题，急。。。。！

[没事眯一会]

和另一台机子做数据交换。代码如下

	public String send(String SendMessage,String clientIP,int clientPort) throws UnknownHostException, IOException{
		System.out.println("------------clientIP="+clientIP+"-------------clientPort="+clientPort);
		Socket s = new Socket(clientIP,clientPort);
		System.out.println("s.getOutputStream()"+s.getOutputStream());
		
		PrintStream out = new PrintStream(s.getOutputStream());
		BufferedReader in = new BufferedReader(new InputStreamReader(s.getInputStream()));
		InputStream is = s.getInputStream();
		System.out.println("SendMessage:"+SendMessage);
		out.print(SendMessage);

		int b = 0;
		while ((b = is.read()) != -1) {
			System.out.println(b);
			bos.write(b);
			System.out.println(b);
		}
		byte[] bytes = bos.toByteArray();*/
		
		int len = -1;
		while((len=is.available()) <=8) {
			len = is.available();
			System.out.println("len:"+len);
		}
		
		byte[] bytes = new byte[8192];
		is.read(bytes, 0 , bytes.length);
		String ReceiveMessage = StringUtil.trim(new String( bytes));
		
		System.out.println("ReceiveMessage:"+ReceiveMessage);
		out.close();
		s.close();
		is.close();
		return ReceiveMessage;
	}

为什么老是在while((len=is.available()) <=8) {
len = is.available();
System.out.println("len:"+len);
}
中循环，后天总是打印len=0；端口 ip都正确，求解！

[brightyq]

类 InputStream 的 available 方法总是返回 0。

详细api文档。

[gyt_cw]

api文档是这么写的：
Returns an estimate of the number of bytes that can be read (or skipped over) from this input stream without blocking by the next invocation of a method for this input stream。

[Mr_sunboy]

返回此输入流方法的下一个调用方可以不受阻塞地从此输入流读取（或跳过）的字节数。