plainsocketimpl.java

This is a resource based on j2me embedded,if you dont understand,you can connection with me .

		// This is normally done in Socket.connect() but some
		// subclasses of Socket may call impl.connect() directly!
		if (socket != null) {
		    socket.setBound();
		    socket.setConnected();
		}
	    } finally {
		releaseFD();
	    }
	} catch (IOException e) {	
	    close();
	    throw e;
	}
    }

    /**
     * Binds the socket to the specified address of the specified local port.
     * @param address the address
     * @param port the port
     */
    protected synchronized void bind(InetAddress address, int lport)
	throws IOException
    {
        socketBind(address, lport);
	if (socket != null)
	    socket.setBound();
	if (serverSocket != null)
	    serverSocket.setBound();
    }

    /**
     * Listens, for a specified amount of time, for connections.
     * @param count the amount of time to listen for connections
     */
    protected synchronized void listen(int count) throws IOException {
	socketListen(count);
    }

    /**
     * Accepts connections.
     * @param s the connection
     */
    protected synchronized void accept(SocketImpl s) throws IOException {
	acquireFD();
	try {
	    socketAccept(s);
	} finally {
	    releaseFD();
	}
    }

    /**
     * Gets an InputStream for this socket.
     */
    protected synchronized InputStream getInputStream() throws IOException {
	if (isClosedOrPending()) {
	    throw new IOException("Socket Closed");
	}
	if (shut_rd) {
	    throw new IOException("Socket input is shutdown");
	}
	if (socketInputStream == null) {
	    socketInputStream = new SocketInputStream(this);
	}
	return socketInputStream;
    }

    void setInputStream(SocketInputStream in) {
	socketInputStream = in;
    }

    /**
     * Gets an OutputStream for this socket.
     */
    protected synchronized OutputStream getOutputStream() throws IOException {
	if (isClosedOrPending()) {
	    throw new IOException("Socket Closed");
	}
        if (shut_wr) {
	    throw new IOException("Socket output is shutdown");
	}
	return new SocketOutputStream(this);
    }

    /**
     * Returns the number of bytes that can be read without blocking.
     */
    protected synchronized int available() throws IOException {
	if (isClosedOrPending()) {
            throw new IOException("Stream closed.");
	}

	/*
	 * If connection has been reset then return 0 to indicate
	 * there are no buffered bytes.
	 */
	if (isConnectionReset()) {
	    return 0;
	}

	/*
	 * If no bytes available and we were previously notified
	 * of a connection reset then we move to the reset state.
	 *
	 * If are notified of a connection reset then check
	 * again if there are bytes buffered on the socket. 
	 */
	int n = 0;
	try { 
	    n = socketAvailable();
	    if (n == 0 && isConnectionResetPending()) {
	        setConnectionReset();
	    }
	} catch (ConnectionResetException exc1) {
	    setConnectionResetPending();
	    try {
	        n = socketAvailable();
		if (n == 0) {
		    setConnectionReset();
		}
	    } catch (ConnectionResetException exc2) {
	    }
	}
	return n;
    }

    /**
     * Closes the socket.
     */
    protected void close() throws IOException {
	synchronized(fdLock) {
	    if (fd != null) {
		if (fdUseCount == 0) {
		    closePending = true;
		    /*
		     * We close the FileDescriptor in two-steps - first the
 		     * "pre-close" which closes the socket but doesn't
		     * release the underlying file descriptor. This operation
		     * may be lengthy due to untransmitted data and a long
		     * linger interval. Once the pre-close is done we do the
		     * actual socket to release the fd.
		     */
		    try {
		        socketPreClose();
		    } finally {
		        socketClose();
		    }
		    fd = null;
		    return;
		} else {
		    /*
		     * If a thread has acquired the fd and a close
		     * isn't pending then use a deferred close.
		     * Also decrement fdUseCount to signal the last
		     * thread that releases the fd to close it.
		     */
		    if (!closePending) {
			closePending = true;
		        fdUseCount--;
			socketPreClose();
		    }
		}
	    }
	}
    }


    /**
     * Shutdown read-half of the socket connection;
     */
    protected void shutdownInput() throws IOException {
      if (fd != null) {
	  socketShutdown(SHUT_RD);
	  if (socketInputStream != null) {
	      socketInputStream.setEOF(true);
	  }
	  shut_rd = true;
      }
    } 

    /**
     * Shutdown write-half of the socket connection;
     */
    protected void shutdownOutput() throws IOException {
      if (fd != null) {
	  socketShutdown(SHUT_WR);
	  shut_wr = true;
      }
    } 

    protected boolean supportsUrgentData () {
        return true;
    }

    protected void sendUrgentData (int data) throws IOException {
        if (fd == null) {
            throw new IOException("Socket Closed");
        }
        socketSendUrgentData (data);
    }

    /**
     * Cleans up if the user forgets to close it.
     */
    protected void finalize() throws IOException {
	close();
    }


    /*
     * "Acquires" and returns the FileDescriptor for this impl
     *
     * A corresponding releaseFD is required to "release" the
     * FileDescriptor.
     */
    public final FileDescriptor acquireFD() {
	synchronized (fdLock) {
	    fdUseCount++;
	    return fd;
	}
    }

    /*
     * "Release" the FileDescriptor for this impl. 
     *
     * If the use count goes to -1 then the socket is closed.
     */
    public final void releaseFD() {
	synchronized (fdLock) {
	    fdUseCount--;
	    if (fdUseCount == -1) {
		if (fd != null) {
	            try {
			socketClose();
	            } catch (IOException e) { 
		    } finally {
		        fd = null;
		    }
		}
	    }
	}
    }

    public boolean isConnectionReset() {
	synchronized (resetLock) {
	    return (resetState == CONNECTION_RESET);
	}
    }

    public boolean isConnectionResetPending() {
	synchronized (resetLock) {
            return (resetState == CONNECTION_RESET_PENDING);
        }
    }

    public void setConnectionReset() {
	synchronized (resetLock) {
            resetState = CONNECTION_RESET;
        }
    }

    public void setConnectionResetPending() {
	synchronized (resetLock) {
            if (resetState == CONNECTION_NOT_RESET) {
                resetState = CONNECTION_RESET_PENDING;
            }
        }

    }

    /*
     * Return true if already closed or close is pending
     */
    public boolean isClosedOrPending() {
	/*
	 * Lock on fdLock to ensure that we wait if a
	 * close is in progress.
	 */
	synchronized (fdLock) {
	    if (closePending || fd == null) {
		return true;
	    } else {
		return false;
	    }
	}
    }

    /*
     * Return the current value of SO_TIMEOUT
     */
    public int getTimeout() {
	return timeout;
    }

    /*
     * "Pre-close" a socket by dup'ing the file descriptor - this enables
     * the socket to be closed without releasing the file descriptor.
     */
    private void socketPreClose() throws IOException {
	socketClose0(true);
    }

    /*
     * Close the socket (and release the file descriptor).
     */
    private void socketClose() throws IOException {
	socketClose0(false);
    }

    private native void socketCreate(boolean isServer) throws IOException;
    private native void socketConnect(InetAddress address, int port, int timeout)
	throws IOException;
    private native void socketBind(InetAddress address, int port)
	throws IOException;
    private native void socketListen(int count)
	throws IOException;
    private native void socketAccept(SocketImpl s)
	throws IOException;
    private native int socketAvailable()
	throws IOException;
    private native void socketClose0(boolean useDeferredClose)
	throws IOException;
    private native void socketShutdown(int howto)
	throws IOException;
    private static native void initProto();
    private native void socketSetOption(int cmd, boolean on, Object value)
	throws SocketException;
    private native int socketGetOption(int opt, Object iaContainerObj) throws SocketException;
    private native void socketSendUrgentData(int data)
        throws IOException;

    public final static int SHUT_RD = 0;
    public final static int SHUT_WR = 1;
}

class InetAddressContainer {
    InetAddress addr;
}