Example usage for java.io RandomAccessFile length

Introduction

In this page you can find the example usage for java.io RandomAccessFile length.

Prototype

public native long length() throws IOException;

Source Link

Document

Returns the length of this file.

Usage

From source file:ReverseFile.java

public static void main(String args[]) throws Exception {
    RandomAccessFile raf = new RandomAccessFile(args[0], "r");
    long position = raf.length();
    while (position > 0) {
        position -= 1;//from  ww  w.  j  a  v a  2 s. c o  m
        raf.seek(position);
        byte b = raf.readByte();
        System.out.print((char) b);
    }
}

From source file:MainClass.java

public static void main(String args[]) {

    try {//www .  j av  a  2s  .c om

        RandomAccessFile raf = new RandomAccessFile(args[0], "r");

        long position = raf.length();

        while (position > 0) {

            position -= 1;

            raf.seek(position);
            byte b = raf.readByte();

            System.out.print((char) b);
        }
    } catch (Exception e) {
        e.printStackTrace();
    }
}

From source file:RawDataFromImageFilePDF.java

public static void main(String[] args) {
    Document document = new Document();
    try {/*from   w  w  w.  j  av a2 s.c o m*/
        PdfWriter.getInstance(document, new FileOutputStream("RawDataFromImageFilePDF.pdf"));
        document.open();

        RandomAccessFile rf = new RandomAccessFile("logo.png", "r");
        int size = (int) rf.length();
        byte imext[] = new byte[size];
        rf.readFully(imext);
        rf.close();

        Image img1 = Image.getInstance(imext);
        img1.setAbsolutePosition(50, 500);
        document.add(img1);

    } catch (Exception e) {
        System.err.println(e.getMessage());
    }
    document.close();
}

From source file:Tail.java

public static void main(String args[]) throws Exception {
    RandomAccessFile raf = new RandomAccessFile(args[0], "r");
    long count = 10;
    long position = raf.length();
    position -= count;//from w  w w.  j  a  va  2s .  c  o  m
    if (position < 0)
        position = 0;
    raf.seek(position);
    while (true) {
        try {
            byte b = raf.readByte();
            System.out.print((char) b);
        } catch (EOFException eofe) {
            break;
        }
    }
}

From source file:RawDataFromImageFileAndManipulationPDF.java

public static void main(String[] args) {
    Document document = new Document();
    try {/*from  w  w  w .  j a  va  2s.com*/
        PdfWriter.getInstance(document, new FileOutputStream("RawDataFromImageFileAndManipulationPDF.pdf"));
        document.open();

        RandomAccessFile rf = new RandomAccessFile("logo.png", "r");
        int size = (int) rf.length();
        byte imext[] = new byte[size];
        rf.readFully(imext);
        rf.close();

        for (int i = 0; i < imext.length; i++) {
            imext[i] = (byte) (imext[i] + 3);
        }

        Image img1 = Image.getInstance(100, 100, 3, 8, imext);
        img1.setAbsolutePosition(200, 200);
        document.add(img1);

    } catch (Exception e) {
        System.err.println(e.getMessage());
    }
    document.close();
}

From source file:Main.java

public static void main(String[] argv) throws Exception {

    RandomAccessFile raf = new RandomAccessFile("a.dat", "rw");
    int x, y;/*w w w. j a va2  s. c  om*/

    for (long i = 0, j = raf.length() - 1; i < j; i++, j--) {
        raf.seek(i);
        x = raf.read();
        raf.seek(j);
        y = raf.read();

        raf.seek(j);
        raf.write(x);
        raf.seek(i);
        raf.write(y);

    }
    raf.close();
}

From source file:MainClass.java

public static void main(String[] args) throws IOException {
    RandomAccessFile raf = new RandomAccessFile(new File("temp.tmp"), "rw");
    raf.writeInt(1);/*from  ww w  .  jav  a 2s  .c o m*/
    for (int i = 0; i < 10; i++) {
        raf.seek(raf.length() - 4);
        raf.writeInt(raf.readInt());
    }
    raf.close();

}

From source file:Main.java

public static void main(String args[]) throws Exception {
    RandomAccessFile fh1 = new RandomAccessFile("a.txt", "r");
    RandomAccessFile fh2 = new RandomAccessFile("b.txt", "r");
    long filesize1 = fh1.length();
    long filesize2 = fh2.length();
    // allocate two buffers large enough to hold entire files
    int bufsize = (int) Math.min(filesize1, filesize2);
    byte[] buffer1 = new byte[bufsize];
    byte[] buffer2 = new byte[bufsize];

    fh1.readFully(buffer1, 0, bufsize);/*  ww  w. j  ava2s.c  o  m*/
    fh2.readFully(buffer2, 0, bufsize);

    for (int i = 0; i < bufsize; i++) {
        if (buffer1[i] != buffer2[i]) {
            System.out.println("Files differ at offset " + i);
            break;
        }
    }
    fh1.close();
    fh2.close();
}

From source file:Main.java

public static void main(String[] args) throws Exception {
    RandomAccessFile f = new RandomAccessFile("hello.txt", "rw");
    FileChannel fc = f.getChannel();
    MappedByteBuffer mbb = fc.map(FileChannel.MapMode.READ_WRITE, 0, f.length());

    int len = (int) f.length();
    for (int i = 0, j = len - 1; i < j; i++, j--) {
        byte b = mbb.get(i);
        mbb.put(i, mbb.get(j));/*  w w  w  . j a  va  2s  .  c  o m*/
        mbb.put(j, b);
    }
    fc.close();
}

From source file:MainClass.java

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

    if (args.length < 2) {
        System.err.println("Usage: java MainClass inFile1 inFile2... outFile");
        return;/*from   ww w  .j a v a  2 s  .  c  o  m*/
    }

    ByteBuffer[] buffers = new ByteBuffer[args.length - 1];
    for (int i = 0; i < args.length - 1; i++) {
        RandomAccessFile raf = new RandomAccessFile(args[i], "r");
        FileChannel channel = raf.getChannel();
        buffers[i] = channel.map(FileChannel.MapMode.READ_ONLY, 0, raf.length());
    }

    FileOutputStream outFile = new FileOutputStream(args[args.length - 1]);
    FileChannel out = outFile.getChannel();
    out.write(buffers);
    out.close();
}