This program writes data to a file.

FileWriteDemo.java

import java.util.Scanner;   // Needed for Scanner class
import java.io.*;           // Needed for File I/O classes

/**
   This program writes data to a file.
*/

public class FileWriteDemo
{
   public static void main(String[] args) throws IOException
   {
      String filename;      // File name
      String friendName;    // Friend's name
      int numFriends;       // Number of friends

      // Create a Scanner object for keyboard input.
      Scanner keyboard = new Scanner(System.in);
      
      // Get the number of friends.
      System.out.print("How many friends do you have? ");
      numFriends = keyboard.nextInt();

      // Consume the remaining newline character.
      keyboard.nextLine();
      
      // Get the filename.
      System.out.print("Enter the filename: ");
      filename = keyboard.nextLine();

      // Open the file.
      PrintWriter outputFile = new PrintWriter(filename);

      // Get data and write it to the file.
      for (int i = 1; i <= numFriends; i++)
      {
         // Get the name of a friend.
         System.out.print("Enter the name of friend " +
                          "number " + i + ": ");
         friendName = keyboard.nextLine();

         // Write the name to the file.
         outputFile.println(friendName);
      }

      // Close the file.
      outputFile.close();
      System.out.println("Data written to the file.");
   }
}