FileChooser.java

import javax.swing.JFileChooser;
import javax.swing.JFrame;
import java.util.Properties;
import java.io.*;
import java.net.*;

/**
 * A class to make working with a file chooser easier for students. It uses a
 * JFileChooser to let the user pick a file and returns the chosen file name.
 * 
 * @author Barb Ericson ericson@cc.gatech.edu
 */
public class FileChooser {

	/////////////////////// methods /////////////////////////////

	/**
	 * Method to get the full path for the passed file name
	 * 
	 * @param fileName the name of a file
	 * @return the full path for the file
	 */
	public static String getMediaPath(String fileName) {
		String path = null;
		String directory = getMediaDirectory();
		boolean done = true;

		// get the full path
		path = directory + fileName;
		return path;
	}

	/**
	 * Method to pick an item using the file chooser
	 * 
	 * @param fileChooser the file Chooser to use
	 * @return the path name
	 */
	public static String pickPath(JFileChooser fileChooser) {
		String path = null;

		/*
		 * create a JFrame to be the parent of the file chooser open dialog if you don't
		 * do this then you may not see the dialog.
		 */
		JFrame frame = new JFrame();
		frame.setAlwaysOnTop(true);

		// get the return value from choosing a file
		int returnVal = fileChooser.showOpenDialog(frame);

		// if the return value says the user picked a file
		if (returnVal == JFileChooser.APPROVE_OPTION)
			path = fileChooser.getSelectedFile().getPath();
		return path;
	}

	/**
	 * Method to let the user pick a file and return the full file name as a string.
	 * If the user didn't pick a file then the file name will be null.
	 * 
	 * @return the full file name of the picked file or null
	 */
	public static String pickAFile() {
		JFileChooser fileChooser = null;

		// start off the file name as null
		String fileName = null;

		// get the current media directory
		String mediaDir = getMediaDirectory();

		/*
		 * create a file for this and check that the directory exists and if it does set
		 * the file chooser to use it
		 */
		try {
			File file = new File(mediaDir);
			if (file.exists())
				fileChooser = new JFileChooser(file);
		} catch (Exception ex) {
		}

		// if no file chooser yet create one
		if (fileChooser == null)
			fileChooser = new JFileChooser();

		// pick the file
		fileName = pickPath(fileChooser);

		return fileName;
	}

	/**
	 * Method to get the directory for the media
	 * 
	 * @return the media directory
	 */
	public static String getMediaDirectory() {
		String directory = null;
		boolean done = false;
		File dirFile = null;

		// try to find the images directory
		try {
			// get the URL for where we loaded this class
			Class currClass = Class.forName("FileChooser");
			URL classURL = currClass.getResource("FileChooser.class");
			URL fileURL = new URL(classURL, "../images/");
			directory = fileURL.getPath();
			directory = URLDecoder.decode(directory, "UTF-8");
			dirFile = new File(directory);
			if (dirFile.exists()) {
				// setMediaPath(directory);
				return directory;
			}
		} catch (Exception ex) {
		}

		return directory;
	}

}