Java IO.pdf - Nguyen Dang Binh

public static void main(String[] args) {
}
try {
FileDialog fd = new FileDialog(new Frame("Not important"),
"Please select a file in the directory you want to list:",
FileDialog.LOAD);
fd.setVisible(true);
if (fd.getDirectory() == null) return;
DirList dl = new DirList(fd.getDirectory());
dl.list();
fd.dispose();
}
catch (IOException e) {System.err.println(e);}
Java I/O
A filename filter can be attached to a file dialog via the dialog's setFilenameFilter()
method:
public synchronized void setFilenameFilter(FilenameFilter filter)
Once a file dialog's filename filter is set, it should only display files that pass through the
filter. In practice, however, filename filters in file dialogs are only truly reliable on Unix.
Many early Mac VMs do not really support this feature, though some of the more recent ones
do. And Windows is almost congenitally unable to support it, because Windows' native file
chooser dialog can only filter by file extension. The problem is that filename filters are
designed for the Motif API. The Windows and Macintosh APIs provide different ways of
achieving the same effect.
Example 13.2 demonstrates the use of a filename filter in a file dialog. The TextChooser
class implements the FilenameFilter interface. The main() method calls the getFile()
method to load a file. Once a file is loaded, it's written on System.out. The getFile()
method uses a file dialog to ask the user what file should be written. A new TextChooser
object is passed to the file dialog's setFilter() method to indicate that this class's accept()
method should be used to filter files. The accept() method accepts files ending in .text, .txt,
.java, .jav, .html , and .htm; all others are rejected.
Example 13.2. The TextChooser Program
import java.io.*;
import java.awt.*;
import com.macfaq.io.*;
public class TextChooser implements FilenameFilter {
public static void main(String[] args) {
try {
File f = getFile();
if (f == null) return;
FileInputStream fin = new FileInputStream(f);
StreamCopier.copy(fin, System.out);
}
catch (IOException e) {System.err.println(e);}
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