Question

I debugged the program and observed that it is stopped when it wants to get input stream from socket:

public Chat(Socket s) throws IOException {
        input = new ObjectInputStream(s.getInputStream()); // stopped here 
        output = new ObjectOutputStream(s.getOutputStream());
        initComponents();
    }

I have closed the open streams and the socket before calling above constructor here:

Socket socket = listeningSocket.accept();
disconnect();
Chat c = new Chat(socket);

and here is the disconnect method:

private void disconnect() throws IOException {
        input.close();
        output.close();
        client.close();
    }

input, output and client are initiated here:

    client = new Socket(chatServer, chatPort);
    input = new ObjectInputStream(client.getInputStream());
    output = new ObjectOutputStream(client.getOutputStream());

this is the stack trace when the program is suspended:

Thread [main] (Suspended)   
    SocketInputStream.socketRead0(FileDescriptor, byte[], int, int, int) line: not available [native method]    
    SocketInputStream.read(byte[], int, int) line: 146  
    ObjectInputStream$PeekInputStream.read(byte[], int, int) line: 2282 
    ObjectInputStream$PeekInputStream.readFully(byte[], int, int) line: 2295    
    ObjectInputStream$BlockDataInputStream.readShort() line: 2766   
    ObjectInputStream.readStreamHeader() line: 797  
    ObjectInputStream.<init>(InputStream) line: 297 
    Chat.<init>(Socket) line: 20    
    Client$5.run() line: 310    
    Client.clientListen() line: 320 
    Client.access$7(Client) line: 302   
    Client$6.run() line: 350    
    Client.main(String[]) line: 352 

please help
thanks 🙂

Answer 1

From ObjectInputStream’s constructor‘s documentation:

This constructor will block until the corresponding ObjectOutputStream
has written and flushed the header.

Is anything being written to the socket from the other end? Are you flushing the stream from the other end?

The ObjectOutputStream’s constructor has documentation saying that users may wish to flush to the stream so that inputstreams don’t block.