This tip will show the ability to access data at random. The real advantage of random access files is as their name implies, once they are opened, they can be read from or written to in a random manner just by using a record number or you can add to the end since you will know how many records are in the file.

 import java.io.File;
import java.io.RandomAccessFile;
import java.io.IOException;

public class DemoRandomAccessFile {

    private static void doAccess() {

        try {
     
            File file = new File("DemoRandomAccessFile.out");
            RandomAccessFile raf = new RandomAccessFile(file, "rw");

            // Read a character
            byte ch = raf.readByte();
            System.out.println("Read first character of file: " + (char)ch);

            // Now read the remaining portion of the line.
            // This will print out from where the file pointer is located
            // (just after the '+' character) and print all remaining characters
            // up until the end of line character.
            System.out.println("Read full line: " + raf.readLine());

            // Seek to the end of file
            raf.seek(file.length());

            // Append to the end of the file
            raf.write(0x0A);
            raf.writeBytes("This will complete the Demo");
            raf.close();
          
        } catch (IOException e) {
            System.out.println("IOException:");
            e.printStackTrace();
        }
    }
 
    public static void main(String[] args) {
        doAccess();
    }

}
}

Output:

Read first character of file: R
Read full line: ohit Khariwal Mohit Parnami

And here it is the DemoRandomAccesFile.out file.

Rohit Khariwal Mohit Parnami
This will complete the Demo