ForwardThread.java

/**
 * ForwardThread handles the TCP forwarding between a socket input stream (source)
 * and a socket output stream (destination). It reads the input stream and forwards
 * everything to the output stream. If some of the streams fails, the forwarding
 * is stopped and the parent thread is notified to close all its connections.
 */
 
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
 
public class ForwardThread extends Thread
{
private static final int READ_BUFFER_SIZE = 8192;
 
    InputStream mInputStream = null;
    OutputStream mOutputStream = null;
 
    ForwardServerClientThread mParent = null;
 
    /**
     * Creates a new traffic forward thread specifying its input stream,
     * output stream and parent thread
     */
    public ForwardThread(ForwardServerClientThread aParent, InputStream aInputStream, OutputStream aOutputStream)
    {
        mInputStream = aInputStream;
        mOutputStream = aOutputStream;
        mParent = aParent;
    }
 
    /**
     * Runs the thread. Until it is possible, reads the input stream and puts read
     * data in the output stream. If reading can not be done (due to exception or
     * when the stream is at his end) or writing is failed, exits the thread.
     */
    public void run()
    {
        byte[] buffer = new byte[READ_BUFFER_SIZE];
        try {
			while (true) {
				int bytesRead = mInputStream.read(buffer);
				if (bytesRead == -1)
				   break; // End of stream is reached --> exit the thread
				mOutputStream.write(buffer, 0, bytesRead);
			}
        } catch (IOException e) {
           // Read/write failed --> connection is broken --> exit the thread
        }
 
        // Notify parent thread that the connection is broken and forwarding should stop
		mParent.connectionBroken();
    } 
}