Files, Streams and Object Serialization - Java: How to Program Early Objects - page 671

48 tests whether the user clicked Cancel by comparing the result with static constant
CANCEL_OPTION . If they're equal, the program terminates. Line 84 calls JFileChooser
method getSelectedFile to retrieve a File object (package java.io ) representing the file
or directory that the user selected, then calls File method toPath to return a Path object.
The program then displays information about the selected file or directory.

1 // Fig. 15.12: JFileChooserDemo.java

2 // Demonstrating JFileChooser.

3 import java.io.IOException;

4 import java.nio.file.DirectoryStream;

5 import java.nio.file.Files;

6 import java.nio.file.Path;

7 import java.nio.file.Paths;

8
9

import javax.swing.JFileChooser;

import javax.swing.JFrame;

10 import javax.swing.JOptionPane;

11 import javax.swing.JScrollPane;

12 import javax.swing.JTextArea;

13
14 public class JFileChooserDemo extends JFrame

15 {

16 private final JTextArea outputArea; // displays file contents

17

18

// set up GUI

19

public JFileChooserDemo() throws IOException

20

{

21

super ( "JFileChooser Demo" );

22

outputArea = new JTextArea();

23

add( new JScrollPane(outputArea)); // outputArea is scrollable

24

analyzePath(); // get Path from user and display info

25

}

26
27

// display information about file or directory user specifies

28

public void analyzePath() throws IOException

29

{

30

// get Path to user-selected file or directory

31

Path path = getFileOrDirectoryPath();

32
33

if (path != null && Files.exists(path)) // if exists, display info

34

{

35

// gather file (or directory) information

36

StringBuilder builder = new StringBuilder();

37

builder.append(String.format( "%s:%n" , path.getFileName()));

38

builder.append(String.format( "%s a directory%n" ,

39

Files.isDirectory(path) ? "Is" : "Is not" ));

40

builder.append(String.format( "%s an absolute path%n" ,

41

path.isAbsolute() ? "Is" : "Is not" ));

42

builder.append(String.format( "Last modified: %s%n" ,

43

Files.getLastModifiedTime(path)));

44

builder.append(String.format( "Size: %s%n" , Files.size(path)));

45

builder.append(String.format( "Path: %s%n" , path));

Fig. 15.12 | Demonstrating JFileChooser . (Part 1 of 2.)