public class FileClassDemo
1: //FileClassDemo.java
2:
3: import java.io.File;
4: import java.io.FileNotFoundException;
5: import java.util.Scanner;
6:
7: public class FileClassDemo
8: {
9: public static void main(String[] args)
10: {
11: System.out.print("Enter file name: ");
12: Scanner keyboard = new Scanner(System.in);
13: String fileName = keyboard.next();
14: File fileObject = new File(fileName);
15: boolean fileOK = false;
16: while (!fileOK)
17: {
18: if (!fileObject.exists())
19: System.out.println("Error: No such file.");
20: else if (!fileObject.canRead())
21: System.out.println("Error: File not readable.");
22: else
23: fileOK = true;
24: if (!fileOK)
25: {
26: System.out.print("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:");
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: inputStream.close();
51: }
52: }