Example usage for java.nio.channels SocketChannel isOpen

List of usage examples for java.nio.channels SocketChannel isOpen

  1. HOME
  2. Java
  3. java
  4. java.nio.channels.*
  5. SocketChannel
  6. isOpen

Introduction

In this page you can find the example usage for java.nio.channels SocketChannel isOpen.

Prototype

public final boolean isOpen()

Source Link

Usage

From source file:HttpGet.java

public static void main(String[] args) {
    SocketChannel server = null; // Channel for reading from server
    FileOutputStream outputStream = null; // Stream to destination file
    WritableByteChannel destination; // Channel to write to it

    try { // Exception handling and channel closing code follows this block

        // Parse the URL. Note we use the new java.net.URI, not URL here.
        URI uri = new URI(args[0]);

        // Now query and verify the various parts of the URI
        String scheme = uri.getScheme();
        if (scheme == null || !scheme.equals("http"))
            throw new IllegalArgumentException("Must use 'http:' protocol");

        String hostname = uri.getHost();

        int port = uri.getPort();
        if (port == -1)
            port = 80; // Use default port if none specified

        String path = uri.getRawPath();
        if (path == null || path.length() == 0)
            path = "/";

        String query = uri.getRawQuery();
        query = (query == null) ? "" : '?' + query;

        // Combine the hostname and port into a single address object.
        // java.net.SocketAddress and InetSocketAddress are new in Java 1.4
        SocketAddress serverAddress = new InetSocketAddress(hostname, port);

        // Open a SocketChannel to the server
        server = SocketChannel.open(serverAddress);

        // Put together the HTTP request we'll send to the server.
        String request = "GET " + path + query + " HTTP/1.1\r\n" + // The request
                "Host: " + hostname + "\r\n" + // Required in HTTP 1.1
                "Connection: close\r\n" + // Don't keep connection open
                "User-Agent: " + HttpGet.class.getName() + "\r\n" + "\r\n"; // Blank
                                                                            // line
                                                                            // indicates
                                                                            // end of
                                                                            // request
                                                                            // headers

        // Now wrap a CharBuffer around that request string
        CharBuffer requestChars = CharBuffer.wrap(request);

        // Get a Charset object to encode the char buffer into bytes
        Charset charset = Charset.forName("ISO-8859-1");

        // Use the charset to encode the request into a byte buffer
        ByteBuffer requestBytes = charset.encode(requestChars);

        // Finally, we can send this HTTP request to the server.
        server.write(requestBytes);//from  w  ww . ja  v  a2 s.c  o m

        // Set up an output channel to send the output to.
        if (args.length > 1) { // Use a specified filename
            outputStream = new FileOutputStream(args[1]);
            destination = outputStream.getChannel();
        } else
            // Or wrap a channel around standard out
            destination = Channels.newChannel(System.out);

        // Allocate a 32 Kilobyte byte buffer for reading the response.
        // Hopefully we'll get a low-level "direct" buffer
        ByteBuffer data = ByteBuffer.allocateDirect(32 * 1024);

        // Have we discarded the HTTP response headers yet?
        boolean skippedHeaders = false;
        // The code sent by the server
        int responseCode = -1;

        // Now loop, reading data from the server channel and writing it
        // to the destination channel until the server indicates that it
        // has no more data.
        while (server.read(data) != -1) { // Read data, and check for end
            data.flip(); // Prepare to extract data from buffer

            // All HTTP reponses begin with a set of HTTP headers, which
            // we need to discard. The headers end with the string
            // "\r\n\r\n", or the bytes 13,10,13,10. If we haven't already
            // skipped them then do so now.
            if (!skippedHeaders) {
                // First, though, read the HTTP response code.
                // Assume that we get the complete first line of the
                // response when the first read() call returns. Assume also
                // that the first 9 bytes are the ASCII characters
                // "HTTP/1.1 ", and that the response code is the ASCII
                // characters in the following three bytes.
                if (responseCode == -1) {
                    responseCode = 100 * (data.get(9) - '0') + 10 * (data.get(10) - '0')
                            + 1 * (data.get(11) - '0');

                    // If there was an error, report it and quit
                    // Note that we do not handle redirect responses.
                    if (responseCode < 200 || responseCode >= 300) {
                        System.err.println("HTTP Error: " + responseCode);
                        System.exit(1);
                    }
                }

                // Now skip the rest of the headers.
                try {
                    for (;;) {
                        if ((data.get() == 13) && (data.get() == 10) && (data.get() == 13)
                                && (data.get() == 10)) {
                            skippedHeaders = true;
                            break;
                        }
                    }
                } catch (BufferUnderflowException e) {
                    // If we arrive here, it means we reached the end of
                    // the buffer and didn't find the end of the headers.
                    // There is a chance that the last 1, 2, or 3 bytes in
                    // the buffer were the beginning of the \r\n\r\n
                    // sequence, so back up a bit.
                    data.position(data.position() - 3);
                    // Now discard the headers we have read
                    data.compact();
                    // And go read more data from the server.
                    continue;
                }
            }

            // Write the data out; drain the buffer fully.
            while (data.hasRemaining())
                destination.write(data);

            // Now that the buffer is drained, put it into fill mode
            // in preparation for reading more data into it.
            data.clear(); // data.compact() also works here
        }
    } catch (Exception e) { // Report any errors that arise
        System.err.println(e);
        System.err.println("Usage: java HttpGet <URL> [<filename>]");
    } finally { // Close the channels and output file stream, if needed
        try {
            if (server != null && server.isOpen())
                server.close();
            if (outputStream != null)
                outputStream.close();
        } catch (IOException e) {
        }
    }
}

From source file:xbird.server.services.RemotePagingService.java

private static boolean doRead(final SocketChannel channel, final ByteBuffer cmdBuffer) throws IOException {
    cmdBuffer.clear();/*from   w  w  w  . j  a v  a  2s .c  o m*/
    int n, count = 0;
    while (channel.isOpen() && (n = channel.read(cmdBuffer)) > 0) {
        count += n;
    }
    return count > 0;
}

From source file:com.jilk.ros.rosbridge.implementation.ROSBridgeWebSocketClient.java

@Override
public void closeBlocking() throws InterruptedException {
    super.closeBlocking();
    try {/*from  w  ww.j  a v  a 2  s .c  o m*/
        Field channelField = this.getClass().getSuperclass().getDeclaredField("channel");
        channelField.setAccessible(true);
        SocketChannel channel = (SocketChannel) channelField.get(this);
        if (channel != null && channel.isOpen()) {
            Socket socket = channel.socket();
            if (socket != null)
                socket.close();
        }
    } catch (Exception ex) {
        System.out.println("Exception in Websocket close hack.");
        ex.printStackTrace();
    }
}

From source file:org.reunionemu.jreunion.server.Network.java

public void disconnect(SocketChannel socketChannel) {

    if (socketChannel.isConnected() && socketChannel.isOpen()) {
        processOutput(socketChannel);//from  ww  w.j  a  v  a 2s.co m
    }
    LoggerFactory.getLogger(Network.class)
            .info("Disconnecting {local=" + socketChannel.socket().getLocalSocketAddress() + " remote="
                    + socketChannel.socket().getRemoteSocketAddress() + "}\n");
    fireEvent(NetworkDisconnectEvent.class, socketChannel);

    try {
        socketChannel.close();
    } catch (IOException e) {
        LoggerFactory.getLogger(this.getClass()).warn("Exception", e);
    }
}

From source file:org.quickserver.util.io.ByteBufferOutputStream.java

private synchronized void writeLastByteBuffer() throws IOException {
    int written = 0;
    while (lastByteBuffer.remaining() != 0) {
        java.nio.channels.SocketChannel sc = handler.getSocketChannel();
        if (sc != null && sc.isOpen()) {
            written = sc.write(lastByteBuffer);
            if (written == 0) {
                break;
            }/*w  w w .jav  a2s  . co m*/
            if (logger.isLoggable(Level.FINEST)) {
                logger.finest("Written " + written + " bytes");
            }
        } else {
            throw new IOException("SocketChannel was closed.");
        }
    }
    if (lastByteBuffer.remaining() == 0) {
        returnBufferBack(lastByteBuffer);
        lastByteBuffer = null;
    }
}

From source file:org.reunionemu.jreunion.server.Network.java

public void notifySend(SocketChannel socketChannel) {
    try {/* w  ww . j  a v  a 2 s.co  m*/
        // we synchronize this to make sure we register the key before the selector gets back to sleep again.
        if (socketChannel.isOpen() && selector.isOpen()) {
            selector.wakeup();
            socketChannel.register(selector, SelectionKey.OP_READ | SelectionKey.OP_WRITE);

        }

    } catch (ClosedChannelException e) {
        //Disconnect detected
    } catch (CancelledKeyException e) {

    } catch (Exception e) {

        LoggerFactory.getLogger(this.getClass()).error("Exception", e);

    }
}

From source file:org.reunionemu.jreunion.server.Network.java

private boolean processOutput(SocketChannel socketChannel) {

    Client client = Server.getInstance().getWorld().getClients().get(socketChannel);

    if (client == null)
        return false;

    if (!socketChannel.isOpen() || !socketChannel.isConnected()) {
        disconnect(socketChannel);/*from   ww  w  . ja v a2 s.c  o m*/
        return false;
    }
    buffer.clear();
    byte[] packetBytes = client.flush();
    if (packetBytes == null)
        return true;
    buffer.put(packetBytes);
    buffer.flip();

    try {
        socketChannel.write(buffer);
    } catch (IOException e) {
        LoggerFactory.getLogger(this.getClass()).error("Exception", e);
        disconnect(socketChannel);
        return false;
    }
    return true;
}

From source file:net.timewalker.ffmq4.transport.tcp.nio.NIOTcpMultiplexer.java

protected void updateConnectInterest(NIOClientSocketHandler clientHandler, Selector selector) {
    SocketChannel socketChannel = clientHandler.getSocketChannel();
    if (!socketChannel.isOpen())
        return;//from  www. j av a 2s  .  co  m

    // We are interested in connect if not already done
    if (!socketChannel.isConnected())
        addInterest(socketChannel, SelectionKey.OP_CONNECT, clientHandler, selector);
    else
        removeInterest(socketChannel, SelectionKey.OP_CONNECT, selector);
}

From source file:net.timewalker.ffmq4.transport.tcp.nio.NIOTcpMultiplexer.java

protected void updateReadInterest(NIOClientSocketHandler clientHandler, Selector selector) {
    SocketChannel socketChannel = clientHandler.getSocketChannel();
    if (!socketChannel.isOpen())
        return;/*from   w w w  .java2s .c  o  m*/
    if (!socketChannel.isConnected())
        return;

    // We are interested in reading only if we have some buffer space left
    if (clientHandler.getInputBuffer().remaining() > 0)
        addInterest(socketChannel, SelectionKey.OP_READ, clientHandler, selector);
    else
        removeInterest(socketChannel, SelectionKey.OP_READ, selector);
}

From source file:net.timewalker.ffmq4.transport.tcp.nio.NIOTcpMultiplexer.java

protected void updateWriteInterest(NIOClientSocketHandler clientHandler, Selector selector) {
    SocketChannel socketChannel = clientHandler.getSocketChannel();
    if (!socketChannel.isOpen())
        return;//from   w  ww . j  a  va2s.c o  m
    if (!socketChannel.isConnected())
        return;

    // We are interested in writing only if there is something in the output buffer or
    // the handler expresses the need to write something
    if (clientHandler.getOutputBuffer().position() > 0 || clientHandler.hasWriteInterest())
        addInterest(socketChannel, SelectionKey.OP_WRITE, null, selector);
    else
        removeInterest(socketChannel, SelectionKey.OP_WRITE, selector);
}