Example usage for java.nio.channels FileChannel write

List of usage examples for java.nio.channels FileChannel write

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Introduction

In this page you can find the example usage for java.nio.channels FileChannel write.

Prototype

public final long write(ByteBuffer[] srcs) throws IOException

Source Link

Document

Writes a sequence of bytes to this channel from the given buffers.

Usage

From source file:ExplicitChannelWrite.java

public static void main(String args[]) {
    FileOutputStream fOut;/* www  . jav  a 2 s . c  om*/
    FileChannel fChan;
    ByteBuffer mBuf;

    try {
        fOut = new FileOutputStream("test.txt");
        fChan = fOut.getChannel();
        mBuf = ByteBuffer.allocateDirect(26);
        for (int i = 0; i < 26; i++)
            mBuf.put((byte) ('A' + i));
        mBuf.rewind();
        fChan.write(mBuf);
        fChan.close();
        fOut.close();
    } catch (IOException exc) {
        System.out.println(exc);
        System.exit(1);
    }
}

From source file:MainClass.java

public static void main(String args[]) {
    FileOutputStream fileOutputStream;
    FileChannel fileChannel;
    ByteBuffer byteBuffer;//from ww w .  ja v  a 2 s .  c o  m

    try {
        fileOutputStream = new FileOutputStream("test.txt");
        fileChannel = fileOutputStream.getChannel();
        byteBuffer = ByteBuffer.allocateDirect(26);

        for (int i = 0; i < 26; i++)
            byteBuffer.put((byte) ('A' + i));
        byteBuffer.rewind();
        fileChannel.write(byteBuffer);
        fileChannel.close();
        fileOutputStream.close();
    } catch (IOException exc) {
        System.out.println(exc);
    }
}

From source file:MainClass.java

public static void main(String[] args) {
    long[] primes = new long[] { 1, 2, 3, 5, 7 };
    File aFile = new File("C:/test/primes.bin");
    FileOutputStream outputFile = null;
    try {//from w w w.ja va 2 s  . co  m
        outputFile = new FileOutputStream(aFile);
    } catch (FileNotFoundException e) {
        e.printStackTrace(System.err);
    }
    FileChannel file = outputFile.getChannel();
    final int BUFFERSIZE = 100;
    ByteBuffer buf = ByteBuffer.allocate(BUFFERSIZE);
    LongBuffer longBuf = buf.asLongBuffer();
    int primesWritten = 0;
    while (primesWritten < primes.length) {
        longBuf.put(primes, primesWritten, min(longBuf.capacity(), primes.length - primesWritten));
        buf.limit(8 * longBuf.position());
        try {
            file.write(buf);
            primesWritten += longBuf.position();
        } catch (IOException e) {
            e.printStackTrace(System.err);
        }
        longBuf.clear();
        buf.clear();
    }
    try {
        System.out.println("File written is " + file.size() + "bytes.");
        outputFile.close();
    } catch (IOException e) {
        e.printStackTrace(System.err);
    }
}

From source file:Main.java

static public void main(String args[]) throws Exception {
    File infile = new File("inFilename");
    File outfile = new File("outFilename");

    RandomAccessFile inraf = new RandomAccessFile(infile, "r");
    RandomAccessFile outraf = new RandomAccessFile(outfile, "rw");

    FileChannel finc = inraf.getChannel();
    FileChannel foutc = outraf.getChannel();

    MappedByteBuffer inmbb = finc.map(FileChannel.MapMode.READ_ONLY, 0, (int) infile.length());

    Charset inCharset = Charset.forName("UTF8");
    Charset outCharset = Charset.forName("UTF16");

    CharsetDecoder inDecoder = inCharset.newDecoder();
    CharsetEncoder outEncoder = outCharset.newEncoder();

    CharBuffer cb = inDecoder.decode(inmbb);
    ByteBuffer outbb = outEncoder.encode(cb);

    foutc.write(outbb);

    inraf.close();//ww  w  . j  a  v a2s. c om
    outraf.close();
}

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();//from  w w w . jav a  2 s.c  om
    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) {
    int count = 100;

    long[] numbers = new long[count];

    for (int i = 0; i < numbers.length; i++) {
        numbers[i] = i;//from  w  w w . ja  va2s . c  om

    }
    File aFile = new File("data.bin");
    FileOutputStream outputFile = null;
    try {
        outputFile = new FileOutputStream(aFile);
    } catch (FileNotFoundException e) {
        e.printStackTrace(System.err);
        System.exit(1);
    }
    FileChannel file = outputFile.getChannel();
    final int BUFFERSIZE = 100;
    ByteBuffer buf = ByteBuffer.allocate(BUFFERSIZE);
    LongBuffer longBuf = buf.asLongBuffer();

    int numberWritten = 0;

    while (numberWritten < numbers.length) {
        longBuf.put(numbers, numberWritten, min(longBuf.capacity(), numbers.length - numberWritten));
        buf.limit(8 * longBuf.position());
        try {
            file.write(buf);
            numberWritten += longBuf.position();
        } catch (IOException e) {
            e.printStackTrace(System.err);
            System.exit(1);
        }
        longBuf.clear();
        buf.clear();
    }

    try {
        System.out.println("File written is " + file.size() + " bytes.");
        outputFile.close();
    } catch (IOException e) {
        e.printStackTrace(System.err);
        System.exit(1);
    }
}

From source file:MainClass.java

public static void main(String[] args) {
    long[] primes = new long[] { 1, 2, 3, 5, 7 };
    File aFile = new File("C:/test/primes.txt");
    FileOutputStream outputFile = null;
    try {//  ww  w . j a v a 2  s.  co m
        outputFile = new FileOutputStream(aFile);
    } catch (FileNotFoundException e) {
        e.printStackTrace(System.err);
    }
    FileChannel file = outputFile.getChannel();
    final int BUFFERSIZE = 100;
    ByteBuffer buf = ByteBuffer.allocate(BUFFERSIZE);
    DoubleBuffer doubleBuf = buf.asDoubleBuffer();
    buf.position(8);
    CharBuffer charBuf = buf.asCharBuffer();
    for (long prime : primes) {
        String primeStr = "prime = " + prime;
        doubleBuf.put(0, (double) primeStr.length());
        charBuf.put(primeStr);
        buf.position(2 * charBuf.position() + 8);
        LongBuffer longBuf = buf.asLongBuffer();
        longBuf.put(prime);
        buf.position(buf.position() + 8);
        buf.flip();
        try {
            file.write(buf);
        } catch (IOException e) {
            e.printStackTrace(System.err);
        }
        buf.clear();
        doubleBuf.clear();
        charBuf.clear();
    }
    try {
        System.out.println("File written is " + file.size() + "bytes.");
        outputFile.close();
    } catch (IOException e) {
        e.printStackTrace(System.err);
    }
}

From source file:MainClass.java

public static void main(String[] args) {
    String phrase = new String("text \n");
    String dirname = "C:/test";
    String filename = "charData.txt";
    File dir = new File(dirname);
    File aFile = new File(dir, filename);
    FileOutputStream outputFile = null;
    try {//from  w w  w. jav a2s .  com
        outputFile = new FileOutputStream(aFile, true);
        System.out.println("File stream created successfully.");
    } catch (FileNotFoundException e) {
        e.printStackTrace(System.err);
    }
    FileChannel outChannel = outputFile.getChannel();
    ByteBuffer buf = ByteBuffer.allocate(1024);
    System.out.println("New buffer:           position = " + buf.position() + "\tLimit = " + buf.limit()
            + "\tcapacity = " + buf.capacity());
    for (char ch : phrase.toCharArray()) {
        buf.putChar(ch);
    }
    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());
    try {
        outChannel.write(buf);
        outputFile.close();
        System.out.println("Buffer contents written to file.");
    } catch (IOException e) {
        e.printStackTrace(System.err);
    }
}

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   w w w  . j  a v a  2s . 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.");
}

From source file:MainClass.java

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

    File aFile = new File("test.txt");
    FileOutputStream outputFile = null;
    try {/* w w  w .j av  a 2 s  .co  m*/
        outputFile = new FileOutputStream(aFile, true);
        System.out.println("File stream created successfully.");
    } catch (FileNotFoundException e) {
        e.printStackTrace(System.err);
    }

    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);
    }
    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());

    try {
        outChannel.write(buf);
        outputFile.close();
        System.out.println("Buffer contents written to file.");
    } catch (IOException e) {
        e.printStackTrace(System.err);
    }
}