Copy Multiple Files,Java Copy Multiple Files Example,How to Copy Multiple Files in Java

Copy multiple files

In this section, you will learn how the data of multiple files is copied to another file. The java.io package provides this facility. For copping the data of multiple file, you need all files in a specified directory where the contents of all files are to be copied to a specified file.

Description of program:

The following program copies the data of two files (source files) in a specified file (target file). At the time of execution of this program, it takes the number of file with their names that have to be copied. The last file is a target file that contains all data of the given source files. The method copyfile() copies the contents of all given files to a specific file. When all data are copied to specified file, it will display a message "File copied" otherwise Exception is thrown and data will not be be copied.


import java.io.*;



public class CopyMultipleFiles{



  public static void main(String[] args)throws IOException {

    BufferedReader bf = new BufferedReader(new InputStreamReader(System.in));

    System.out.println("Enter Number of files that have to be copied:");

    int n = Integer.parseInt(bf.readLine());

    String fileName[] = new String[n];



    for (int i=0; i<n; i++){

      System.out.println("Enter file name:");

      fileName[i] = bf.readLine();

    }



    for (int j=0; j<n-1; j++){

      copyfile(fileName[j],fileName[j+1]);

    }

    System.out.println("File copied.");

  }



  public static void copyfile(String srFile, String dtFile){

    try{

      File f1 = new File(srFile);

      File f2 = new File(dtFile);

      InputStream in = new FileInputStream(f1);

      //For Append the file.

      OutputStream out = new FileOutputStream(f2,true);



      //For Overwrite the file.

//      OutputStream out = new FileOutputStream(f2);



      byte[] buf = new byte[1024];

      int len;

      while ((len = in.read(buf)) > 0){

        out.write(buf, 0, len);

      }

    in.close();

    out.close();

    }

    catch(FileNotFoundException ex){

      System.out.println(ex.getMessage() + " in the specified directory.");

      System.exit(0);

    }

    catch(IOException e){

      System.out.println(e.getMessage());   

    }

  }

}

Output of program:

Here the data of "LAN.log" file and "CopyMultipleFiles.java" file are copied to the copy.txt file.

C:\vinod>javac CopyMultipleFiles.java

C:\vinod>java CopyMultipleFiles
Enter Number of files that have to be coppied:
3
Enter file name:
LAN.log
Enter file name:
CopyMultipleFiles.java
Enter file name:
copy.txt
File copied.