public class FileClassDemo
1: import java.util.Scanner;
2: import java.io.File;
3: import java.io.FileNotFoundException;
4:
5: public class FileClassDemo
6: {
7: public static void main(String[] args)
8: {
9: System.out.print("Enter file name: ");
10: Scanner keyboard = new Scanner(System.in);
11: String fileName = keyboard.next( );
12:
13: File fileObject = new File(fileName);
14: boolean fileOK = false;
15: while (!fileOK)
16: {
17: if (!fileObject.exists( ))
18: System.out.println("No such file");
19: else if (!fileObject.canRead( ))
20: System.out.println("That file is not readable.");
21: else
22: fileOK = true;
23:
24: if (!fileOK)
25: {
26: System.out.println("Enter file name again:");
27: fileName = keyboard.next( );
28: fileObject = new File(fileName);
29: }
30: }
31:
32: Scanner inputStream = null;
33: System.out.println("The file " + fileName +
34: "\ncontains the following lines\n");
35: try
36: {
37: inputStream = new Scanner(new File(fileName));
38: }
39: catch (FileNotFoundException e)
40: {
41: System.out.println("Error opening the file " + fileName);
42: System.exit(0);
43: }
44:
45: while (inputStream.hasNextLine())
46: {
47: String line = inputStream.nextLine();
48: System.out.println(line);
49: }
50:
51: inputStream.close();
52: }
53: }