通过Perl和Java之间的套接字发送字节数组

Question

I have a big issue with my java client.

Server: perl, with IO::Socket;

$n is the socket

    sub listen{    
 while(1){
  my $n = $_[0]->accept();
  my $thread;
  my $thread2;
  $thread = threads->create('talk', $n);
  $thread2 = threads->create('recu', $n);
 }

When a client send a message to the server

    sub talk{
 my $n = $_[0];
 while(<$n>){
  print $n $_;
 }

In 'talk' the server send the client message back to the client

Client: Java, in a Thread I send a byte array ->

static DataOutputStream os;

...

     public static void handleMsg(byte [] b){
  try {
   os.write(b);
  } catch (IOException e) {
   // TODO Auto-generated catch block
   e.printStackTrace();
  }

 }

->

<pre><code>
    byte[] buff = new byte[]{10,4};
ThreadListen.handleMsg(buff);
</code></pre>
I receive in the run() method only the first byte in the array (10)
<pre><code>
    public void run(){
  DataInputStream in = null;
  try{
   in = new DataInputStream(s.getInputStream());
  } catch (IOException e) {
   System.out.println("in or out failed");
   System.exit(-1);
  }

  while(true){
   try{
    byte[] buff = new byte[6];
    int b = in.read(buff, 0, buff.length);
   }catch (IOException e) {
    System.out.println("Read failed");
    System.exit(-1);
   }
  }
 }

If I try to send

byte[] buff = new byte[]{50,4};
ThreadListen.handleMsg(buff);

I receive nothing!!!

Did i missed something, I assume that if I send

byte[] buff = new byte[]{50,4};

I should receive 50,4 :)

Thanks,

Answer 1

Your Perl code is doing <$n> so it's fetching data line-by-line. since 10 is the line-feed character, receiving a {10,4} sequence means it gets an empty line (which it prints back) and then a character 4. Even if it receives that (some debug messages in the Perl code would help), the print back to the socket may not complete if the socket is block-buffered (likely the default) without flushing the socket filehandle.

Answer 2

您可能想显式使用read （而不是隐式的readline ，顾名思义， readline读到行尾或EOF）从套接字读取。