Leave the given two documents alone file1.txt and file2.txt. Our Task is to blend the two records into third document say file3.txt yet combining ought to be finished by line by line then again. Coming up next are steps to combine on the other hand.

1. Create PrintWriter object for file3.txt
2. Open BufferedReader for file1.txt
3. Open BufferedReader for file2.txt
4. Run a loop to copy each line of file1.txt and then file2.txt to file3.txt
5. Flush PrintWriter stream and close resources.

To effectively run the beneath program file1.txt and file2.txt must ways out in same organizer OR give full way to them.

// Java program to merge two
// files into third file alternatively

import java.io.*;

public class FileMerge
{
	public static void main(String[] args) throws IOException
	{
		// PrintWriter object for file3.txt
		PrintWriter pw = new PrintWriter("file3.txt");
		
		// BufferedReader object for file1.txt
		BufferedReader br1 = new BufferedReader(new FileReader("file1.txt"));
		BufferedReader br2 = new BufferedReader(new FileReader("file2.txt"));
		
		
		String line1 = br1.readLine();
		String line2 = br2.readLine();
		
		// loop to copy lines of
		// file1.txt and file2.txt
		// to file3.txt alternatively
		while (line1 != null || line2 !=null)
		{
			if(line1 != null)
			{
				pw.println(line1);
				line1 = br1.readLine();
			}
			
			if(line2 != null)
			{
				pw.println(line2);
				line2 = br2.readLine();
			}
		}
	
		pw.flush();
		
		// closing resources
		br1.close();
		br2.close();
		pw.close();
		
		System.out.println("Merged file1.txt and file2.txt
alternatively into file3.txt");
	}
}

Output:

Merged file1.txt and file2.txt into file3.txt

Note : In the event that file3.txt exist in cwd(current working index) it will be overwritten by above program in any case new record will be made.