Example usage for java.nio.channels SocketChannel read

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

Introduction

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

Prototype

public final long read(ByteBuffer[] dsts) throws IOException 

Source Link

Usage

From source file:Main.java

public static void main(String[] argv) throws Exception {
    Selector selector = Selector.open();

    ServerSocketChannel ssChannel1 = ServerSocketChannel.open();
    ssChannel1.configureBlocking(false);
    ssChannel1.socket().bind(new InetSocketAddress(80));

    ServerSocketChannel ssChannel2 = ServerSocketChannel.open();
    ssChannel2.configureBlocking(false);
    ssChannel2.socket().bind(new InetSocketAddress(81));

    ssChannel1.register(selector, SelectionKey.OP_ACCEPT);
    ssChannel2.register(selector, SelectionKey.OP_ACCEPT);

    while (true) {
        selector.select();// w  ww  .j a v a  2s  . co m
        Iterator it = selector.selectedKeys().iterator();
        while (it.hasNext()) {
            SelectionKey selKey = (SelectionKey) it.next();
            it.remove();

            if (selKey.isAcceptable()) {
                ServerSocketChannel ssChannel = (ServerSocketChannel) selKey.channel();
                SocketChannel sc = ssChannel.accept();
                ByteBuffer bb = ByteBuffer.allocate(100);
                sc.read(bb);

            }
        }
    }
}

From source file:Main.java

public static void main(String[] argv) throws Exception {
    ByteBuffer buf = ByteBuffer.allocateDirect(1024);
    SocketChannel sChannel = SocketChannel.open();
    sChannel.configureBlocking(false);// ww  w  . jav a2s .com
    sChannel.connect(new InetSocketAddress("hostName", 12345));

    int numBytesRead = sChannel.read(buf);

    if (numBytesRead == -1) {
        sChannel.close();
    } else {
        buf.flip();
    }
}

From source file:Main.java

public static void main(String[] argv) throws Exception {
    Selector selector = Selector.open();

    ServerSocketChannel ssChannel1 = ServerSocketChannel.open();
    ssChannel1.configureBlocking(false);
    ssChannel1.socket().bind(new InetSocketAddress(80));

    ServerSocketChannel ssChannel2 = ServerSocketChannel.open();
    ssChannel2.configureBlocking(false);
    ssChannel2.socket().bind(new InetSocketAddress(81));

    ssChannel1.register(selector, SelectionKey.OP_ACCEPT);
    ssChannel2.register(selector, SelectionKey.OP_ACCEPT);

    while (true) {
        selector.select();/*from   w  ww . j av  a  2  s.c o m*/
        Iterator it = selector.selectedKeys().iterator();
        while (it.hasNext()) {
            SelectionKey selKey = (SelectionKey) it.next();
            it.remove();

            if (selKey.isAcceptable()) {
                ServerSocketChannel ssChannel = (ServerSocketChannel) selKey.channel();
                SocketChannel sc = ssChannel.accept();
                ByteBuffer buf = ByteBuffer.allocate(100);
                int numBytesRead = sc.read(buf);

                if (numBytesRead == -1) {
                    sc.close();
                } else {
                    // Read the bytes from the buffer
                }
                int numBytesWritten = sc.write(buf);
            }
        }
    }
}

From source file:MainClass.java

public static void main(String[] args) throws Exception {
    int port = 19;

    SocketAddress address = new InetSocketAddress("127.0.0.1", port);
    SocketChannel client = SocketChannel.open(address);

    ByteBuffer buffer = ByteBuffer.allocate(74);
    WritableByteChannel out = Channels.newChannel(System.out);

    while (client.read(buffer) != -1) {
        buffer.flip();//ww  w.  j  a va  2s .  co  m
        out.write(buffer);
        buffer.clear();
    }
}

From source file:MainClass.java

public static void main(String[] args) throws Exception {
    int port = 1919;

    SocketAddress address = new InetSocketAddress("127.0.0.1", port);
    SocketChannel client = SocketChannel.open(address);
    ByteBuffer buffer = ByteBuffer.allocate(4);
    IntBuffer view = buffer.asIntBuffer();

    for (int expected = 0;; expected++) {
        client.read(buffer);
        int actual = view.get();
        buffer.clear();//from  w  w  w .  j  a va2  s. c om
        view.rewind();

        if (actual != expected) {
            System.err.println("Expected " + expected + "; was " + actual);
            break;
        }
        System.out.println(actual);
    }
}

From source file:MainClass.java

public static void main(String[] args) throws IOException {

    URL u = new URL("http://www.java2s.com");
    String host = u.getHost();/* w w w .  ja va 2s. co m*/
    int port = 80;
    String file = "/";

    SocketAddress remote = new InetSocketAddress(host, port);
    SocketChannel channel = SocketChannel.open(remote);
    FileOutputStream out = new FileOutputStream("yourfile.htm");
    FileChannel localFile = out.getChannel();

    String request = "GET " + file + " HTTP/1.1\r\n" + "User-Agent: HTTPGrab\r\n" + "Accept: text/*\r\n"
            + "Connection: close\r\n" + "Host: " + host + "\r\n" + "\r\n";

    ByteBuffer header = ByteBuffer.wrap(request.getBytes("US-ASCII"));
    channel.write(header);

    ByteBuffer buffer = ByteBuffer.allocate(8192);
    while (channel.read(buffer) != -1) {
        buffer.flip();
        localFile.write(buffer);
        buffer.clear();
    }

    localFile.close();
    channel.close();
}

From source file:MainClass.java

public static void main(String[] args) throws IOException {
    Charset charset = Charset.forName("ISO-8859-1");
    CharsetEncoder encoder = charset.newEncoder();
    CharsetDecoder decoder = charset.newDecoder();

    ByteBuffer buffer = ByteBuffer.allocate(512);

    Selector selector = Selector.open();

    ServerSocketChannel server = ServerSocketChannel.open();
    server.socket().bind(new java.net.InetSocketAddress(8000));
    server.configureBlocking(false);/*www  . ja  va 2 s .c om*/
    SelectionKey serverkey = server.register(selector, SelectionKey.OP_ACCEPT);

    for (;;) {
        selector.select();
        Set keys = selector.selectedKeys();

        for (Iterator i = keys.iterator(); i.hasNext();) {
            SelectionKey key = (SelectionKey) i.next();
            i.remove();

            if (key == serverkey) {
                if (key.isAcceptable()) {
                    SocketChannel client = server.accept();
                    client.configureBlocking(false);
                    SelectionKey clientkey = client.register(selector, SelectionKey.OP_READ);
                    clientkey.attach(new Integer(0));
                }
            } else {
                SocketChannel client = (SocketChannel) key.channel();
                if (!key.isReadable())
                    continue;
                int bytesread = client.read(buffer);
                if (bytesread == -1) {
                    key.cancel();
                    client.close();
                    continue;
                }
                buffer.flip();
                String request = decoder.decode(buffer).toString();
                buffer.clear();
                if (request.trim().equals("quit")) {
                    client.write(encoder.encode(CharBuffer.wrap("Bye.")));
                    key.cancel();
                    client.close();
                } else {
                    int num = ((Integer) key.attachment()).intValue();
                    String response = num + ": " + request.toUpperCase();
                    client.write(encoder.encode(CharBuffer.wrap(response)));
                    key.attach(new Integer(num + 1));
                }
            }
        }
    }
}

From source file:GetWebPageApp.java

public static void main(String args[]) throws Exception {
    String resource, host, file;//from   w w w  .  ja  v a 2s  .c o m
    int slashPos;

    resource = "www.java2s.com/index.htm"; // skip HTTP://
    slashPos = resource.indexOf('/'); // find host/file separator
    if (slashPos < 0) {
        resource = resource + "/";
        slashPos = resource.indexOf('/');
    }
    file = resource.substring(slashPos); // isolate host and file parts
    host = resource.substring(0, slashPos);
    System.out.println("Host to contact: '" + host + "'");
    System.out.println("File to fetch : '" + file + "'");

    SocketChannel channel = null;

    try {
        Charset charset = Charset.forName("ISO-8859-1");
        CharsetDecoder decoder = charset.newDecoder();
        CharsetEncoder encoder = charset.newEncoder();

        ByteBuffer buffer = ByteBuffer.allocateDirect(1024);
        CharBuffer charBuffer = CharBuffer.allocate(1024);

        InetSocketAddress socketAddress = new InetSocketAddress(host, 80);
        channel = SocketChannel.open();
        channel.configureBlocking(false);
        channel.connect(socketAddress);

        selector = Selector.open();

        channel.register(selector, SelectionKey.OP_CONNECT | SelectionKey.OP_READ);

        while (selector.select(500) > 0) {
            Set readyKeys = selector.selectedKeys();
            try {
                Iterator readyItor = readyKeys.iterator();

                while (readyItor.hasNext()) {

                    SelectionKey key = (SelectionKey) readyItor.next();
                    readyItor.remove();
                    SocketChannel keyChannel = (SocketChannel) key.channel();

                    if (key.isConnectable()) {
                        if (keyChannel.isConnectionPending()) {
                            keyChannel.finishConnect();
                        }
                        String request = "GET " + file + " \r\n\r\n";
                        keyChannel.write(encoder.encode(CharBuffer.wrap(request)));
                    } else if (key.isReadable()) {
                        keyChannel.read(buffer);
                        buffer.flip();

                        decoder.decode(buffer, charBuffer, false);
                        charBuffer.flip();
                        System.out.print(charBuffer);

                        buffer.clear();
                        charBuffer.clear();

                    } else {
                        System.err.println("Unknown key");
                    }
                }
            } catch (ConcurrentModificationException e) {
            }
        }
    } catch (UnknownHostException e) {
        System.err.println(e);
    } catch (IOException e) {
        System.err.println(e);
    } finally {
        if (channel != null) {
            try {
                channel.close();
            } catch (IOException ignored) {
            }
        }
    }
    System.out.println("\nDone.");
}

From source file:GetWebPageDemo.java

public static void main(String args[]) throws Exception {
    String resource, host, file;//  ww w.j  a v a2  s .  c om
    int slashPos;

    resource = "www.java2s.com/index.htm";
    slashPos = resource.indexOf('/'); // find host/file separator
    if (slashPos < 0) {
        resource = resource + "/";
        slashPos = resource.indexOf('/');
    }
    file = resource.substring(slashPos); // isolate host and file parts
    host = resource.substring(0, slashPos);
    System.out.println("Host to contact: '" + host + "'");
    System.out.println("File to fetch : '" + file + "'");

    SocketChannel channel = null;

    try {
        Charset charset = Charset.forName("ISO-8859-1");
        CharsetDecoder decoder = charset.newDecoder();
        CharsetEncoder encoder = charset.newEncoder();

        ByteBuffer buffer = ByteBuffer.allocateDirect(1024);
        CharBuffer charBuffer = CharBuffer.allocate(1024);

        InetSocketAddress socketAddress = new InetSocketAddress(host, 80);
        channel = SocketChannel.open();
        channel.connect(socketAddress);

        String request = "GET " + file + " \r\n\r\n";
        channel.write(encoder.encode(CharBuffer.wrap(request)));

        while ((channel.read(buffer)) != -1) {
            buffer.flip();
            decoder.decode(buffer, charBuffer, false);
            charBuffer.flip();
            System.out.println(charBuffer);
            buffer.clear();
            charBuffer.clear();
        }
    } catch (UnknownHostException e) {
        System.err.println(e);
    } catch (IOException e) {
        System.err.println(e);
    } finally {
        if (channel != null) {
            try {
                channel.close();
            } catch (IOException ignored) {
            }
        }
    }

    System.out.println("\nDone.");
}

From source file:PrintServiceWebInterface.java

public static void main(String[] args) throws IOException {
    // Get the character encoders and decoders we'll need
    Charset charset = Charset.forName("ISO-8859-1");
    CharsetEncoder encoder = charset.newEncoder();

    // The HTTP headers we send back to the client are fixed
    String headers = "HTTP/1.1 200 OK\r\n" + "Content-type: text/html\r\n" + "Connection: close\r\n" + "\r\n";

    // We'll use two buffers in our response. One holds the fixed
    // headers, and the other holds the variable body of the response.
    ByteBuffer[] buffers = new ByteBuffer[2];
    buffers[0] = encoder.encode(CharBuffer.wrap(headers));
    ByteBuffer body = ByteBuffer.allocateDirect(16 * 1024);
    buffers[1] = body;//from  w  w  w .  ja v a2s .c  om

    // Find all available PrintService objects to describe
    PrintService[] services = PrintServiceLookup.lookupPrintServices(null, null);

    // All of the channels we use in this code will be in non-blocking
    // mode. So we create a Selector object that will block while
    // monitoring all of the channels and will only stop blocking when
    // one or more of the channels is ready for I/O of some sort.
    Selector selector = Selector.open();

    // Create a new ServerSocketChannel, and bind it to port 8000.
    // Note that we have to do this using the underlying ServerSocket.
    ServerSocketChannel server = ServerSocketChannel.open();
    server.socket().bind(new java.net.InetSocketAddress(8000));

    // Put the ServerSocketChannel into non-blocking mode
    server.configureBlocking(false);

    // Now register the channel with the Selector. The SelectionKey
    // represents the registration of this channel with this Selector.
    SelectionKey serverkey = server.register(selector, SelectionKey.OP_ACCEPT);

    for (;;) { // The main server loop. The server runs forever.
        // This call blocks until there is activity on one of the
        // registered channels. This is the key method in non-blocking I/O.
        selector.select();

        // Get a java.util.Set containing the SelectionKey objects for
        // all channels that are ready for I/O.
        Set keys = selector.selectedKeys();

        // Use a java.util.Iterator to loop through the selected keys
        for (Iterator i = keys.iterator(); i.hasNext();) {
            // Get the next SelectionKey in the set, and then remove it
            // from the set. It must be removed explicitly, or it will
            // be returned again by the next call to select().
            SelectionKey key = (SelectionKey) i.next();
            i.remove();

            // Check whether this key is the SelectionKey we got when
            // we registered the ServerSocketChannel.
            if (key == serverkey) {
                // Activity on the ServerSocketChannel means a client
                // is trying to connect to the server.
                if (key.isAcceptable()) {
                    // Accept the client connection, and obtain a
                    // SocketChannel to communicate with the client.
                    SocketChannel client = server.accept();

                    // Make sure we actually got a connection
                    if (client == null)
                        continue;

                    // Put the client channel in non-blocking mode.
                    client.configureBlocking(false);

                    // Now register the client channel with the Selector,
                    // specifying that we'd like to know when there is
                    // data ready to read on the channel.
                    SelectionKey clientkey = client.register(selector, SelectionKey.OP_READ);
                }
            } else {
                // If the key we got from the Set of keys is not the
                // ServerSocketChannel key, then it must be a key
                // representing one of the client connections.
                // Get the channel from the key.
                SocketChannel client = (SocketChannel) key.channel();

                // If we got here, it should mean that there is data to
                // be read from the channel, but we double-check here.
                if (!key.isReadable())
                    continue;

                // Now read bytes from the client. We assume that
                // we get all the client's bytes in one read operation
                client.read(body);

                // The data we read should be some kind of HTTP GET
                // request. We don't bother checking it however since
                // there is only one page of data we know how to return.
                body.clear();

                // Build an HTML document as our reponse.
                // The body of the document contains PrintService details
                StringBuffer response = new StringBuffer();
                response.append(
                        "<html><head><title>Printer Status</title></head>" + "<body><h1>Printer Status</h1>");
                for (int s = 0; s < services.length; s++) {
                    PrintService service = services[s];
                    response.append("<h2>").append(service.getName()).append("</h2><table>");
                    Attribute[] attrs = service.getAttributes().toArray();
                    for (int a = 0; a < attrs.length; a++) {
                        Attribute attr = attrs[a];
                        response.append("<tr><td>").append(attr.getName()).append("</td><td>").append(attr)
                                .append("</tr>");
                    }
                    response.append("</table>");
                }
                response.append("</body></html>\r\n");

                // Encode the response into the body ByteBuffer
                encoder.reset();
                encoder.encode(CharBuffer.wrap(response), body, true);
                encoder.flush(body);

                body.flip(); // Prepare the body buffer to be drained
                // While there are bytes left to write
                while (body.hasRemaining()) {
                    // Write both header and body buffers
                    client.write(buffers);
                }
                buffers[0].flip(); // Prepare header buffer for next write
                body.clear(); // Prepare body buffer for next read

                // Once we've sent our response, we have no more interest
                // in the client channel or its SelectionKey
                client.close(); // Close the channel.
                key.cancel(); // Tell Selector to stop monitoring it.
            }
        }
    }
}