Java 无法确定是否成功接收文件

我试图用java在服务器类中使用ServerSocketChannel，在客户端类中使用SocketChannel从服务器向客户端发送文件。两个类对象都处于阻塞模式

文件发送得很好，但我无法通过编程确定文件已到达！我必须转到客户端类中保存发送文件的文件夹，检查其大小，并将其大小与服务器类中的原始文件进行比较。这是因为

System.out.println（“接收：+filename”）语句从未在我的客户机类中执行。然而，
System.out.println（“发送的文件数据”）

服务器类代码

ServerSocketChannel ssc=ServerSocketChannel.open();
ssc.bind(new InetSocketAddress(5002));

SocketChannel clientchannel=ssc.accept();

FileChannel sbc=FileChannel.open(f.toPath());
                 ByteBuffer buff=ByteBuffer.allocate(10000000);
                 int size=(int)sbc.size();
                 int read=1000000;
                 System.out.println("file size: "+size);

                 int bytesread=sbc.read(buff);

                 while(bytesread != -1){

                buff.flip();
               clientchannel.write(buff);
                buff.clear();
                System.out.println("current position: "+sbc.position());
                bytesread=sbc.read(buff);
                 }
  System.out.println("file data sent");

clientChannel=SocketChannel.open(address);
     ByteBuffer bb=ByteBuffer.allocate(10000000);
     int bytesRead=clientChannel.read(bb);

FileOutputStream bout =new FileOutputStream(file);
FileChannel sbc=bout.getChannel();

     while(bytesRead !=-1){
   System.out.println(" bytes read :"+bytesRead);
       bb.flip();
       sbc.write(bb);
       bb.clear();
      bytesRead=clientChannel.read(bb);
     }
     System.out.println("received: "+filename);

客户端类代码

ServerSocketChannel ssc=ServerSocketChannel.open();
ssc.bind(new InetSocketAddress(5002));

SocketChannel clientchannel=ssc.accept();

FileChannel sbc=FileChannel.open(f.toPath());
                 ByteBuffer buff=ByteBuffer.allocate(10000000);
                 int size=(int)sbc.size();
                 int read=1000000;
                 System.out.println("file size: "+size);

                 int bytesread=sbc.read(buff);

                 while(bytesread != -1){

                buff.flip();
               clientchannel.write(buff);
                buff.clear();
                System.out.println("current position: "+sbc.position());
                bytesread=sbc.read(buff);
                 }
  System.out.println("file data sent");

clientChannel=SocketChannel.open(address);
     ByteBuffer bb=ByteBuffer.allocate(10000000);
     int bytesRead=clientChannel.read(bb);

FileOutputStream bout =new FileOutputStream(file);
FileChannel sbc=bout.getChannel();

     while(bytesRead !=-1){
   System.out.println(" bytes read :"+bytesRead);
       bb.flip();
       sbc.write(bb);
       bb.clear();
      bytesRead=clientChannel.read(bb);
     }
     System.out.println("received: "+filename);

问题

生成最后一条语句
System.out.println（“received:+filename”）的代码中缺少了什么不执行。这就像我的客户端程序在收到所有字节后陷入死锁一样
 您可以在发送文件后关闭服务器类中的频道，以便频道上的任何进一步读取将返回
-1
，即流结束指示

ServerSocketChannel ssc=ServerSocketChannel.open();
ssc.bind(new InetSocketAddress(5002));

SocketChannel clientchannel;
try{
clientchannel=ssc.accept();
FileChannel sbc=FileChannel.open(f.toPath());
             ByteBuffer buff=ByteBuffer.allocate(10000000);
             int size=(int)sbc.size();
             int read=1000000;
             System.out.println("file size: "+size);

             int bytesread=sbc.read(buff);

             while(bytesread != -1){

            buff.flip();
           clientchannel.write(buff);
            buff.clear();
            System.out.println("current position: "+sbc.position());
            bytesread=sbc.read(buff);
             }
System.out.println("file data sent");

}catch(IOException ioe){
ioe.printStackTrace();
}finally{
 if(clientchannel !=null){
        try {
            clientchannel.close();

        } catch (IOException ex) {
            ex.printStackTrace();
        }
        }
}