java网络套接字服务端读取字节数为0

[zay12345]

客户端采用的是阻塞io，服务器采用的是nio，客户端向服务器发送了一个字符串，服务端这边读取字节数始终为0，我猜想有可能是未读取完整，使用了while循环反复读取仍然是0，这是为什么呢？有没什么办法解决呢？求大神指导

客户端代码

public class Tst {
	public static void main(String[] args){
		try {
			Socket socket=new Socket("127.0.0.1",9999);
			String[] strs={new String("str1\r\n"),
					new String("str2\r\n"),
					new String("str3\r\n")};
			OutputStream out=socket.getOutputStream();
			int i=0;
			while(i<3){
				try {
					
					Thread.sleep(3000);
					System.out.println("准备发送！");
				} catch (InterruptedException e) {
					// TODO Auto-generated catch block
					e.printStackTrace();
				}
				out.write(strs[i].getBytes());
				out.flush();
				
				i++;
			}
			if(out!=null){
				out.close();
			}
			
			socket.close();
			
			
		} catch (UnknownHostException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		} catch (IOException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
		
		
	}
}

服务器代码

public class TstServer {

    private Selector selector = null;
    static final int port = 9999;
    private Charset charset = Charset.forName("UTF-8");
    
    
    public void init() throws IOException
    {
        selector = Selector.open();
        ServerSocketChannel server = ServerSocketChannel.open();
        server.bind(new InetSocketAddress(port));
        server.configureBlocking(false);
        server.register(selector, SelectionKey.OP_ACCEPT); 
        
        
        while(true) {
            int readyChannels = selector.select();
            if(readyChannels == 0) continue; 
            Set selectedKeys = selector.selectedKeys(); 
            Iterator keyIterator = selectedKeys.iterator();
            while(keyIterator.hasNext()) {
                 SelectionKey sk = (SelectionKey) keyIterator.next();
                 keyIterator.remove();
                 dealWithSelectionKey(server,sk);
            }
        }
    }
    
    public void dealWithSelectionKey(ServerSocketChannel server,SelectionKey sk) throws IOException {
        if(sk.isAcceptable())
        {
            SocketChannel sc = server.accept();
            sc.configureBlocking(false);
            sc.register(selector, SelectionKey.OP_READ);
            sk.interestOps(SelectionKey.OP_ACCEPT);
            System.out.println("连接请求来自 :" + sc.getRemoteAddress());
        }
        //处理来自客户端的数据读取请求
        if(sk.isReadable())
        {
            SocketChannel sc = (SocketChannel)sk.channel(); 
            ByteBuffer buff = ByteBuffer.allocate(1024);
            StringBuilder content = new StringBuilder();
            try
            {
            	int length=0;
                while(true)
                {
                	System.out.println("接收了一次, 大小为" + length);
                    buff.flip();
                    content.append(charset.decode(buff));
                    
                    length=sc.read(buff);
                    if(length==0){
                    	try {
							Thread.sleep(1000);
						} catch (InterruptedException e) {
							e.printStackTrace();
						}
                    }
                    if(buff.toString().endsWith("\r\n")) break;
                    
                }
                System.out.println("Server is listening from client " + sc.getRemoteAddress() + " data rev is: " + content);
                sk.interestOps(SelectionKey.OP_READ);
            }
            catch (IOException io)
            {
                sk.cancel();
                if(sk.channel() != null)
                {
                    sk.channel().close();
                }
            }
           
            
        }
    }
    
    public static void main(String[] args) throws IOException 
    {
        new TstServer().init();
    }
}

[attilax]

第一解决方法，可能是cache的问题，你flush一下，或者多发送几个字符 第二，使用socket框架吧，nio太原始低级了。自己要搞的细节太多了。使用socket类库一般可靠性高些