SocketChannel 的信息发送和读取有关问题

SocketChannel 的信息发送和读取问题
代码如下。 问题是我给服务器端发送了内容，但是在服务器没有接受到内容，长度为-1,getInt获得的结果是0 ，求帮助 
服务器的代码：
public void SocketChannelServer() throws Exception {
  Selector seletor = Selector.open();
  ServerSocketChannel serverchannel = ServerSocketChannel.open();
  SocketChannel socketChannel = SocketChannel.open();
  serverchannel.configureBlocking(false);
  serverchannel.bind(new InetSocketAddress("127.0.0.1", 6000));
  serverchannel.register(seletor, SelectionKey.OP_ACCEPT);
  while (seletor.select() > 0) {// 启动服务，阻塞
    Set<SelectionKey> keys = seletor.selectedKeys();
    Iterator<SelectionKey> itera = keys.iterator();
    
    while (itera.hasNext()) {
     SelectionKey key = itera.next();
     if (key.isAcceptable()) {
      System.out.println("成功");
      socketChannel = serverchannel.accept();
      socketChannel.configureBlocking(false);
      socketChannel.register(seletor, SelectionKey.OP_READ
        | SelectionKey.OP_WRITE);

 
     } else if (!key.isValid()) {
      itera.remove();
      continue;
     } else if (key.isConnectable()) {
      System.out.println("连接成功");
      serverchannel.register(seletor, SelectionKey.OP_READ
        | SelectionKey.OP_WRITE);
     } else if (key.isReadable()) {
      SocketChannel socketChannelNew = (SocketChannel)key.channel();
      ByteBuffer bytebuffer = ByteBuffer.allocateDirect(100);
      int j=socketChannelNew.read(bytebuffer);
      System.out.println("长度" + j);
      int y = bytebuffer.getInt();
      System.out.println("读取" + y);
      socketChannelNew.close();
     } 
      else if (key.isWritable()) {
     } 
     itera.remove();
    }
  }

 
客户端的代码：
int i=0;
  SocketChannel channel=SocketChannel.open();
  channel.configureBlocking(false);
  InetSocketAddress remote=new InetSocketAddress("127.0.0.1",6000);
  channel.connect(remote);
  try {
   while (!channel.finishConnect()) {
    Thread.sleep(1000);
    i++;
    System.out.println("连接中。。。");
    if (i > 5) {
     break;
    }
    ;
   }
  } catch (Exception e) {
   System.out.println("连接失败");
   return;