Point at Default Directory File

Many times you will want some control over the file dialog box. You may want to specify that it should start looking in a particular directory. To start the file dialog box at a default directory, call the FileDialog class's setDirectory(String dir) method where dir is the path to the directory.
Here is an example of using the setDirectory method:

fd.setDirectory("/usr/tmp");

To specify that the file dialog should appear with a particular directory opened or a particular file in that directory selected, you can invoke the setDirectory() and setFile() methods:

public synchronized void setDirectory(String directory)
public synchronized void setFile(String file)

For example:

fd.setDirectory("/etc");
fd.setFile("passwd");

You make the file dialog visible by invoking the file dialog's show() method, just like any other window:

fd.show();

As soon as the file dialog becomes visible, the calling thread stops and waits for the user to choose a file. The operating system takes over and handles user interaction until the user chooses a file or presses the Cancel button. At this point, the file dialog disappears from the screen, and normal program execution resumes.

public String getFile()
public String getDirectory()

FileDialog fd = new FileDialog(new Frame(), "Please choose a file:",
FileDialog.LOAD);
fd.setVisible(true);
File f = new File(fd.getDirectory(), fd.getFile());

If the user cancels the file dialog without selecting a file, getFile() and getDirectory() return null. You should be ready to handle this, or you'll bump into a NullPointerException in short order.