Example usage for java.io RandomAccessFile RandomAccessFile

List of usage examples for java.io RandomAccessFile RandomAccessFile

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Introduction

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

Prototype

public RandomAccessFile(File file, String mode) throws FileNotFoundException

Source Link

Document

Creates a random access file stream to read from, and optionally to write to, the file specified by the File argument.

Usage

From source file:Main.java

public static void main(String[] args) {
    try {/*from w  w w .  j a v  a  2  s  . c  o m*/
        String s = "Hello world from java2s.com";

        RandomAccessFile raf = new RandomAccessFile("c:/test.txt", "rw");

        // write something in the file
        raf.writeUTF(s);

        // set the file pointer at 0 position
        raf.seek(0);

        // create an array equal to the length of raf
        byte[] arr = new byte[(int) raf.length()];

        // read the file
        raf.readFully(arr);

        // create a new string based on arr
        String s2 = new String(arr);

        System.out.println(s2);
        raf.close();
    } catch (IOException ex) {
        ex.printStackTrace();
    }

}

From source file:Main.java

public static void main(String[] args) {
    try {/* w  w  w.j  a v a2s  .  c om*/
        String s = "Hello World from java2s.com";

        RandomAccessFile raf = new RandomAccessFile("c:/test.txt", "rw");

        raf.writeChars(s);

        raf.seek(0);

        for (int i = 0; i < 15; i++) {
            System.out.println(raf.readChar());
        }

        raf.seek(0);

        raf.writeChars("This is an example from java2s.com");

        raf.seek(0);

        for (int i = 0; i < 20; i++) {
            System.out.println(raf.readChar());
        }
        raf.close();
    } catch (IOException ex) {
        ex.printStackTrace();
    }

}

From source file:Main.java

public static void main(String[] args) {
    try {/*from   ww  w . j  a v  a 2 s .  co m*/
        String s = "Hello world from java2s.com";

        RandomAccessFile raf = new RandomAccessFile("c:/test.txt", "rw");

        // write something in the file
        raf.writeUTF(s);

        // set the file pointer at 0 position
        raf.seek(0);

        // create an array equal to the length of raf
        byte[] arr = new byte[10];

        // read the file
        raf.readFully(arr, 3, 7);

        // create a new string based on arr
        String s2 = new String(arr);

        // print it
        System.out.println(s2);
        raf.close();
    } catch (IOException ex) {
        ex.printStackTrace();
    }

}

From source file:Main.java

public static void main(String[] argv) throws Exception {
    FileChannel rwChannel = new RandomAccessFile(new File("test.txt"), "rw").getChannel();
    FileChannel roChannel = new RandomAccessFile(new File("test.txt"), "r").getChannel();

    FileChannel pvChannel = new RandomAccessFile(new File("text.txt"), "rw").getChannel();
    ByteBuffer pvBuf = roChannel.map(FileChannel.MapMode.READ_WRITE, 0, (int) rwChannel.size());
}

From source file:MainClass.java

public static void main(String[] argv) throws Exception {
    RandomAccessFile raf = new RandomAccessFile("test.txt", "r");
    FileChannel fc = raf.getChannel();
    MappedByteBuffer buffer = fc.map(FileChannel.MapMode.READ_ONLY, 0, fc.size());

    buffer.clear();/*from w  w w .  ja  va 2 s .  co m*/
    buffer.flip();

    System.out.println("hasArray=" + buffer.hasArray());
    System.out.println(buffer.toString());

    System.out.flush();
}

From source file:Main.java

public static void main(String[] args) {
    try {//from   ww  w  .  ja v  a2s  . c  o m
        String s = "Hello world from java2s.com";

        RandomAccessFile raf = new RandomAccessFile("c:/test.txt", "rw");

        raf.writeUTF(s);

        raf.seek(0);

        System.out.println(raf.readUTF());

        raf.seek(0);

        raf.writeUTF("This is an example from java2s.com");

        raf.seek(0);

        System.out.println(raf.readUTF());
        raf.close();
    } catch (Exception ex) {
        ex.printStackTrace();
    }

}

From source file:InputOutputDemoPrimitive.java

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

    //Read and write parts of file "raf.dat" in arbitrary order:
    RandomAccessFile raf = new RandomAccessFile("r.dat", "rw");
    raf.writeDouble(3.1415);/*  www .  java2  s.  com*/
    raf.writeInt(42);
    raf.seek(0);
    System.out.println(raf.readDouble() + " " + raf.readInt());

}

From source file:MainClass.java

public static void main(String[] args) throws IOException {
    FileChannel fc = new RandomAccessFile("temp.tmp", "rw").getChannel();
    IntBuffer ib = fc.map(FileChannel.MapMode.READ_WRITE, 0, fc.size()).asIntBuffer();
    for (int i = 0; i < 10; i++)
        ib.put(i);//www.j ava  2s. c o m
    fc.close();

}

From source file:Main.java

public static void main(String[] args) {
    try {/*from   w  w  w  .jav  a  2 s.  co m*/
        // create a new RandomAccessFile with filename Example
        RandomAccessFile raf = new RandomAccessFile("c:/test.txt", "rw");

        // write something in the file
        raf.writeUTF("java2s.com Hello World");

        // set the file pointer at 0 position
        raf.seek(0);

        // read and print the contents of the file
        System.out.println(raf.readUTF());

        // return the file pointer
        System.out.println(raf.getFilePointer());

        // change the position of the file pointer
        raf.seek(5);

        // return the file pointer
        System.out.println(raf.getFilePointer());

        // close the strea and release resources
        raf.close();
    } catch (IOException ex) {
        ex.printStackTrace();
    }

}

From source file:MainClass.java

public static void main(String[] argv) throws IOException {
    RandomAccessFile randomAccessFile = new RandomAccessFile("test.dat", "r");

    randomAccessFile.seek(1000);/*from  w w w.j  av  a2 s  .  co m*/

    FileChannel fileChannel = randomAccessFile.getChannel();

    // This will print "1000"
    System.out.println("file pos: " + fileChannel.position());

    randomAccessFile.seek(500);

    // This will print "500"
    System.out.println("file pos: " + fileChannel.position());

    fileChannel.position(200);

    // This will print "200"
    System.out.println("file pos: " + randomAccessFile.getFilePointer());
}