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:MainClass.java

public static void main(String[] args) throws Exception {
    FileChannel fc = new FileOutputStream("data2.txt").getChannel();
    fc.write(ByteBuffer.wrap("Some text".getBytes("UTF-16BE")));
    fc.close();/*from w w w .  j a va  2 s . c  o m*/
    ByteBuffer buff = ByteBuffer.allocate(BSIZE);
    // Now try reading again:
    fc = new FileInputStream("data2.txt").getChannel();
    buff.clear();
    fc.read(buff);
    buff.flip();
    System.out.println(buff.asCharBuffer());

}

From source file:MainClass.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);//w  w w .j a v a  2s .c  om
    System.out.println(cb.rewind());
    symmetricScramble(cb);
    System.out.println(cb.rewind());
    symmetricScramble(cb);
    System.out.println(cb.rewind());
}

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);/*from   ww  w.  ja  v  a2 s  . com*/
        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));
        }
        sbc.position(0);
        buffer = ByteBuffer.allocate(1024);
        String encoding = System.getProperty("file.encoding");
        int numberOfBytesRead = sbc.read(buffer);
        System.out.println("Number of bytes read: " + numberOfBytesRead);
        while (numberOfBytesRead > 0) {
            buffer.rewind();
            System.out.print("[" + Charset.forName(encoding).decode(buffer) + "]");
            buffer.flip();
            numberOfBytesRead = sbc.read(buffer);
            System.out.println("\nNumber of bytes read: " + numberOfBytesRead);
        }

    }

}

From source file:MainClass.java

public static void main(String[] args) {
    try {//  ww  w . j av  a 2  s.  c  o m
        File aFile = new File("test.txt");

        FileOutputStream outputFile = null;
        outputFile = new FileOutputStream(aFile, true);
        FileChannel outChannel = outputFile.getChannel();

        ByteBuffer buf = ByteBuffer.allocate(200);

        buf.putInt(10).asCharBuffer().put("www.java2s.com");

        buf.position(10).flip();
        outChannel.write(buf);
        buf.clear();

        outputFile.close();

    } catch (Exception e) {
        e.printStackTrace();

    }

}

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();/* w w  w.ja va 2s  .  c  om*/
        out.write(buffer);
        buffer.clear();
    }
}

From source file:MainClass.java

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

    FileInputStream inFile = new FileInputStream(args[0]);
    FileOutputStream outFile = new FileOutputStream(args[1]);

    FileChannel inChannel = inFile.getChannel();
    FileChannel outChannel = outFile.getChannel();

    for (ByteBuffer buffer = ByteBuffer.allocate(1024 * 1024); inChannel.read(buffer) != -1; buffer.clear()) {
        buffer.flip();// w w  w  .  j  a v a2 s . com
        while (buffer.hasRemaining())
            outChannel.write(buffer);
    }

    inChannel.close();
    outChannel.close();
}

From source file:MainClass.java

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

    FileInputStream inFile = new FileInputStream(args[0]);
    FileOutputStream outFile = new FileOutputStream(args[1]);

    FileChannel inChannel = inFile.getChannel();
    FileChannel outChannel = outFile.getChannel();

    ByteBuffer buffer = ByteBuffer.allocate(1024 * 1024);
    int bytesRead = 0;
    while (bytesRead >= 0 || buffer.hasRemaining()) {
        if (bytesRead != -1)
            bytesRead = inChannel.read(buffer);
        buffer.flip();//w w  w  .  j a v a  2s  . co  m
        outChannel.write(buffer);
        buffer.compact();
    }

    inChannel.close();
    outChannel.close();
}

From source file:Main.java

public static void main(String[] args) throws Exception {
    String source = "s.txt";
    String destination = "d.txt";

    FileInputStream fis = new FileInputStream(source);
    FileOutputStream fos = new FileOutputStream(destination);

    FileChannel fci = fis.getChannel();
    FileChannel fco = fos.getChannel();

    ByteBuffer buffer = ByteBuffer.allocate(1024);

    while (true) {
        int read = fci.read(buffer);

        if (read == -1)
            break;
        buffer.flip();//  w ww.j av  a  2 s .c  o m
        fco.write(buffer);
        buffer.clear();
    }
}

From source file:MainClass.java

public static void main(String[] args) throws Exception {
    FileChannel fc = new FileOutputStream("data2.txt").getChannel();
    fc.write(ByteBuffer.wrap("Some text".getBytes()));
    fc.close();/*  w w  w .  ja  va2  s  . c om*/
    fc = new FileInputStream("data2.txt").getChannel();
    ByteBuffer buff = ByteBuffer.allocate(BSIZE);
    fc.read(buff);
    buff.flip();

    System.out.println(buff.asCharBuffer());
    // Decode using this system's default Charset:
    buff.rewind();
    String encoding = System.getProperty("file.encoding");
    System.out.println("Decoded using " + encoding + ": " + Charset.forName(encoding).decode(buff));
    // Or, we could encode with something that will print:
    fc = new FileOutputStream("data2.txt").getChannel();
    fc.write(ByteBuffer.wrap("Some text".getBytes("UTF-16BE")));
    fc.close();

}

From source file:Main.java

public static void main(String[] args) throws Exception {
    String phrase = new String("www.java2s.com\n");

    File aFile = new File("test.txt");
    FileOutputStream outputFile = null;
    outputFile = new FileOutputStream(aFile, true);
    System.out.println("File stream created successfully.");

    FileChannel outChannel = outputFile.getChannel();

    ByteBuffer buf = ByteBuffer.allocate(1024);
    System.out.println("New buffer:           position = " + buf.position() + "\tLimit = " + buf.limit()
            + "\tcapacity = " + buf.capacity());
    // Load the data into the buffer
    for (char ch : phrase.toCharArray()) {
        buf.putChar(ch);/*from   ww w.j av a 2  s.c o m*/
    }
    System.out.println("Buffer after loading: position = " + buf.position() + "\tLimit = " + buf.limit()
            + "\tcapacity = " + buf.capacity());
    buf.flip();
    System.out.println("Buffer after flip:    position = " + buf.position() + "\tLimit = " + buf.limit()
            + "\tcapacity = " + buf.capacity());

    outChannel.write(buf);
    outputFile.close();
    System.out.println("Buffer contents written to file.");
}