File I/O - Absolute Java - page 610

The File Class
The File class is like a wrapper class for file names. The constructor for the class File
takes a string as an argument and produces an object that can be thought of as the file
with that name. You can use the File object and methods of the class File to answer
questions, such as the following: Does the file exist? Does your program have permission
to read the file? Does your program have permission to write to the file? Display 10.14 has a
summary of some of the methods for the class File .
EXAMPLE
File fileObject = new File("data.txt");
if ( ! fileObject.canRead())
System.out.println("File data.txt is not readable.");

Display 10.11 Using the File Class (part 1 of 2)

1 import java.util.Scanner;
2 import java.io.File;
3 import java.io.PrintWriter;
4 import java.io.FileOutputStream;
5 import java.io.FileNotFoundException;
6 public class FileClassDemo
7 {
8 public static void main(String[] args)
9 {
10 Scanner keyboard = new Scanner(System.in);
11 String line = null ;
12 String fileName = null ;

13 System.out.println("I will store a line of text for you.");
14 System.out.println("Enter the line of text:");
15 line = keyboard.nextLine();
16 System.out.println("Enter a file name to hold the line:");
17 fileName = keyboard.nextLine();
18 File fileObject = new File(fileName);
19
20 while (fileObject.exists())
21 {
22 System.out.println("There already is a file named "
23 + fileName);
24 System.out.println("Enter a different file name:");
25 fileName = keyboard.nextLine();
26 fileObject = new File(fileName);
27 }