Java - Reading from a buffered reader (from a socket) is pausing the thread

Question

I have a thread that reads characters from a Buffered reader (created from a socket as follows):

inputStream = new BufferedReader(new InputStreamReader(clien         


        

Answer 1

Socket socket;

// Assuming socket is connected and not null

if(socket != null){
    if(socket.getInputStream().available() > 0){
        byte[] buffer;
        buffer = new byte[socket.getInputStream().available];
        socket.getInputStream().read(buffer);

        // Your code here to deal with buffer.

    }
}

If you want to write to the socket,

OutputStream mmOutStream;
mmOutStream = socket.getOutputStream();

public void write(byte[] buffer) {
    try {
        mmOutStream.write(buffer);
    } catch (IOException e) {
        Log.e(TAG, "Exception during write ", e);
    }
}

Answer 2

Your "sender" is waiting to receive data back from the "receiver", and this is where the code waits indefinitely. Is the receiver supposed to be sending a response when it gets a message?

Answer 3

Implement a protocol where you send the length of your data in your headers so the server/client knows how much data to expect.

Answer 4

You have to create ServerSocket That listen to client in every loop.

ServerSocket socket = new ServerSocket(3000);

Here is my run() method that will wait for client Socket every time

public void run(){
        boolean dataRecieved = false;
        char[] inputChars = new char[1024];
        int charsRead = 0;

        while (!stopNow) {
            try {
                System.out.println("Listen To Clients:");

                // The ServerSocket has to listen the client each time.
                InputStreamReader isr = new InputStreamReader( socket.accept().getInputStream() );
                inputStream = new BufferedReader( isr );

                //Read 1024 characters. Note: This will pause the thread when stream is empty.
                System.out.println("Reading from stream:");

                if ((charsRead =  inputStream.read(inputChars)) != -1)
                {
                    System.out.println("Chars read from stream: " + charsRead);  
                    System.out.println(inputChars);
                    System.out.flush();
                }
            } 
            catch (IOException e) 
            {
                e.printStackTrace();
            }
        }
    }

You have another minor mistake that halts the code and remove the line

charsRead =  inputStream.read(inputChars); //<< THIS LINE IS PAUSING THE THREAD!>

Because this line is moved in an if statement.

Answer 5

java.io.InputStream.read() is a blocking call, which means if no data is available the thread halts until data becomes available.

For non-blocking I/O, use classes from the java.nio package.