Merge Files into One Java

PROGRAM TO MERGE FILES

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

Note : If file3.txt exist in cwd(current working directory) then it will be overwritten by above program otherwise new file will be created.

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