Example usage for java.nio ByteBuffer allocate

Introduction

In this page you can find the example usage for java.nio ByteBuffer allocate.

Prototype

public static ByteBuffer allocate(int capacity)

Source Link

Document

Creates a byte buffer based on a newly allocated byte array.

Usage

From source file:Test.java

public static void main(String[] args) throws IOException {
    Path path = Paths.get("/users.txt");

    try (SeekableByteChannel sbc = Files.newByteChannel(path)) {
        ByteBuffer buffer = ByteBuffer.allocate(1024);

        sbc.position(4);//  w  w w .  j  a  v a 2  s.co m
        sbc.read(buffer);
        for (int i = 0; i < 5; i++) {
            System.out.print((char) buffer.get(i));
        }

        buffer.clear();
        sbc.position(0);
        sbc.read(buffer);
        for (int i = 0; i < 4; i++) {
            System.out.print((char) buffer.get(i));
        }

    }
}

From source file:Main.java

public static void main(String[] args) throws Exception {
    DatagramChannel server = null;
    server = DatagramChannel.open();
    InetSocketAddress sAddr = new InetSocketAddress("localhost", 8989);
    server.bind(sAddr);/*w w  w  .j  a v  a  2 s  .  c  o  m*/
    ByteBuffer buffer = ByteBuffer.allocate(1024);

    while (true) {
        System.out.println("Waiting for a  message  from" + "  a  remote  host at " + sAddr);
        SocketAddress remoteAddr = server.receive(buffer);
        buffer.flip();
        int limits = buffer.limit();
        byte bytes[] = new byte[limits];
        buffer.get(bytes, 0, limits);
        String msg = new String(bytes);

        System.out.println("Client at " + remoteAddr + "  says: " + msg);
        buffer.rewind();
        server.send(buffer, remoteAddr);
        buffer.clear();
    }
    //server.close();
}

From source file:UDPTimeServer.java

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

    int port = 37;

    ByteBuffer in = ByteBuffer.allocate(8192);
    ByteBuffer out = ByteBuffer.allocate(8);
    out.order(ByteOrder.BIG_ENDIAN);
    SocketAddress address = new InetSocketAddress(port);
    DatagramChannel channel = DatagramChannel.open();
    DatagramSocket socket = channel.socket();
    socket.bind(address);//from   w w w. j  a  v a 2s.c  om
    System.err.println("bound to " + address);
    while (true) {
        try {
            in.clear();
            SocketAddress client = channel.receive(in);
            System.err.println(client);
            long secondsSince1970 = System.currentTimeMillis();
            out.clear();
            out.putLong(secondsSince1970);
            out.flip();

            out.position(4);
            channel.send(out, client);
        } catch (Exception ex) {
            System.err.println(ex);
        }
    }
}

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);//from w w w . java 2s .c o  m
        int actual = view.get();
        buffer.clear();
        view.rewind();

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

From source file:Main.java

static public void main(String args[]) throws Exception {
    FileInputStream fin = new FileInputStream("infile.txt");
    FileOutputStream fout = new FileOutputStream("outfile.txt");

    FileChannel inc = fin.getChannel();
    FileChannel outc = fout.getChannel();

    ByteBuffer bb = ByteBuffer.allocate(1024);

    while (true) {
        int ret = inc.read(bb);
        if (ret == -1)
            break;
        bb.flip();// ww w  . j  av a2s .  com
        outc.write(bb);
        bb.clear();
    }
}

From source file:MainClass.java

public static void main(String[] args) throws Exception {
    String fromFileName = args[0];
    String toFileName = args[1];// ww w. j av a2  s .  c  o m
    FileChannel in = new FileInputStream(fromFileName).getChannel();
    FileChannel out = new FileOutputStream(toFileName).getChannel();

    ByteBuffer buff = ByteBuffer.allocate(32 * 1024);

    while (in.read(buff) > 0) {
        buff.flip();
        out.write(buff);
        buff.clear();
    }

    in.close();
    out.close();
}

From source file:CopyChannels.java

public static void main(String[] args) throws Exception {
    String fromFileName = "from.txt";
    String toFileName = "to.txt";
    FileChannel in = new FileInputStream(fromFileName).getChannel();
    FileChannel out = new FileOutputStream(toFileName).getChannel();

    ByteBuffer buff = ByteBuffer.allocate(32 * 1024);

    while (in.read(buff) > 0) {
        buff.flip();/*from  w  ww  . ja v a2 s  . c om*/
        out.write(buff);
        buff.clear();
    }

    in.close();
    out.close();
}

From source file:ExplicitChannelRead.java

public static void main(String args[]) {
    FileInputStream fIn;/*from   w  w  w  .java 2 s. c o  m*/
    FileChannel fChan;
    long fSize;
    ByteBuffer mBuf;

    try {
        fIn = new FileInputStream("test.txt");
        fChan = fIn.getChannel();
        fSize = fChan.size();
        mBuf = ByteBuffer.allocate((int) fSize);
        fChan.read(mBuf);
        mBuf.rewind();
        for (int i = 0; i < fSize; i++)
            System.out.print((char) mBuf.get());
        fChan.close();
        fIn.close();
    } catch (IOException exc) {
        System.out.println(exc);
        System.exit(1);
    }
}

From source file:MainClass.java

public static void main(String args[]) {
    FileInputStream fIn;/*from   www  .jav a2s  .c o  m*/
    FileChannel fChan;
    long fSize;
    ByteBuffer mBuf;

    try {
        fIn = new FileInputStream("test.txt");

        fChan = fIn.getChannel();

        fSize = fChan.size();

        mBuf = ByteBuffer.allocate((int) fSize);

        fChan.read(mBuf);

        mBuf.rewind();

        for (int i = 0; i < fSize; i++)
            System.out.print((char) mBuf.get());
        fChan.close();
        fIn.close();
    } catch (IOException exc) {
        System.out.println(exc);
    }
}

From source file:Main.java

public static void main(String[] args) {
    char[] data = "UsingBuffers".toCharArray();
    ByteBuffer bb = ByteBuffer.allocate(data.length * 2);
    CharBuffer cb = bb.asCharBuffer();
    cb.put(data);//  ww w.  j  a va2s  .  c o m
    System.out.println(cb.rewind());
    symmetricScramble(cb);
    System.out.println(cb.rewind());
    symmetricScramble(cb);
    System.out.println(cb.rewind());

}