Java.io.RandomAccessFile.writeDouble() Method

Description

The java.io.RandomAccessFile.writeDouble(double v) method converts the double argument to a long using the doubleToLongBits method in class Double, and then writes that long value to the file as an eight-byte quantity, high byte first. The write starts at the current position of the file pointer.

Declaration

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

public final void writeDouble(double v)

Parameters

• v -- a double 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.writeDouble() method.

package com.tutorialspoint;

import java.io.*;

public class RandomAccessFileDemo {

   public static void main(String[] args) {
      try {
         double d = 1847.4986;

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

         // write a double in the file
         raf.writeDouble(d);

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

         // read double
         System.out.println("" + raf.readDouble());

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

         // write a double at the start
         raf.writeDouble(473.5645);

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

         // read double
         System.out.println("" + raf.readDouble());
      } 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:

1847.4986
473.5645