Java.io.RandomAccessFile.writeLong() Method

Description

The java.io.RandomAccessFile.writeLong(long v) method writes a long to the file as eight bytes, high byte first. The write starts at the current position of the file pointer.

Declaration

Following is the declaration for java.io.RandomAccessFile.writeLong() method

public final void writeLong(long v)

Parameters

• v -- a long value to be written.

Return Value

This method does not return a value.

Exception

• IOException -- if an I/O error occurs.

Example

The following example shows the usage of java.io.RandomAccessFile.writeLong() method.

package com.tutorialspoint;

import java.io.*;

public class RandomAccessFileDemo {

   public static void main(String[] args) {
      try {
         long f = 184750874576l;

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

         // write a long in the file
         raf.writeLong(f);

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

         // read long
         System.out.println("" + raf.readLong());

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

         // write a long at the start
         raf.writeLong(20000000000l);

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

         // read long
         System.out.println("" + raf.readLong());
      } catch (IOException ex) {
         ex.printStackTrace();
      }

   }
}

Assuming we have a text file c:/test.txt, which has the following content. This file will be used as an input for our example program:

ABCDE  

Let us compile and run the above program, this will produce the following result:

184750874576
20000000000