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Java RandomAccessFile writeLong() Method with Example

RandomAccessFile Class writeLong() method: Here, we are going to learn about the writeLong() method of RandomAccessFile Class with its syntax and example.
Submitted by Preeti Jain, on March 23, 2020

RandomAccessFile Class writeLong() method

• writeLong() method is available in java.io package.
• writeLong() method is used to write the long value to the file as 8 bytes directly without any conversion.
• writeLong() method is a non-static method, it is accessible with the class object only and if we try to access the method with the class name then we will get an error.
• writeLong() method may throw an exception at the time of writing long value.
  IOException: This exception may throw an exception while performing input/output operation.

Syntax:

    public final void writeLong(long val);

Parameter(s):

• long val – represents a long value to write.

Return value:

The return type of this method is void, it returns nothing.

Example:

// Java program to demonstrate the example 
// of void writeLong(long val)a method of
// RandomAccessFile

import java.io.*;

class RAFWriteLong {
 public static void main(String[] args) throws Exception {
  long lo = 124587584 l;
  // Instantiate a random access file
  // object with file name and permissions
  RandomAccessFile ra_f = new RandomAccessFile("e:/includehelp.txt", "rw");

  // By using writeLong() method is to 
  // write a long value to the file
  ra_f.writeLong(lo);

  // by using seek() method is to 
  // set the current file indicator
  // from where read/write could 
  // start i.e. we set here 0 so reading
  // will be done from 0 till EOF
  ra_f.seek(0);

  // By using readLong() method is to 
  // read a long value from this file
  System.out.print(" ra_f.readLong(): " + ra_f.readLong());

  // By using close() method isto
  // close this stream ran_f
  ra_f.close();
 }
}

Output

 ra_f.readLong(): 124587584