Java.io.RandomAccessFile.readDouble() Method


Advertisements


Description

The java.io.RandomAccessFile.readDouble() method reads a double from this file. This method reads a long value, starting at the current file pointer, as if by the readLong method and then converts that long to a double using the longBitsToDouble method in class Double.

Declaration

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

public final double readDouble()

Parameters

NA

Return Value

This method returns the next eight bytes of this file, interpreted as a double.

Exception

  • IOException − If an I/O error occurs.Not thrown if end-of-file has been reached.

  • EOFException − If this file reaches the end before reading eight bytes.

Example

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

package com.tutorialspoint;

import java.io.*;

public class RandomAccessFileDemo {

   public static void main(String[] args) {
   
      try {
         double d = 1.5987475;
         
         // create a new RandomAccessFile with filename test
         RandomAccessFile raf = new RandomAccessFile("c:/test.txt", "rw");

         // write something in the file
         raf.writeDouble(765.497634);

         // 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(d);

         // 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 −

765.497634
1.5987475

java_io_randomaccessfile.htm

Advertisements