Java.io.RandomAccessFile.readLong() Method

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Description

The java.io.RandomAccessFile.readLong() method reads a signed 64-bit integer from this file. This method reads eight bytes from the file, starting at the current file pointer.

Declaration

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

public final long readLong()

Parameters

NA

Return Value

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

Exception

• IOException − If an I/O error occurs.

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

Example

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

package com.tutorialspoint;

import java.io.*;

public class RandomAccessFileDemo {
   public static void main(String[] args) {

      try {
         long l = 536475859696l;
         
         // create a new RandomAccessFile with filename test
         RandomAccessFile raf = new RandomAccessFile("c:/test.txt", "rw");

         // write something in the file
         raf.writeLong(l);

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

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

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

         // write something in the file
         raf.writeLong(4876347485l);

         raf.seek(0);
         // print the 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 −

536475859696
4876347485