uploaderfilefilter.java

用java applet實現的檔案上傳功能

/*  Copyright (C) 2005 Simon David Rycroft

	This program is free software; you can redistribute it and/or
	modify it under the terms of the GNU General Public License
	as published by the Free Software Foundation; either version 2
	of the License, or (at your option) any later version.

	This program is distributed in the hope that it will be useful,
	but WITHOUT ANY WARRANTY; without even the implied warranty of
	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
	GNU General Public License for more details.

	You should have received a copy of the GNU General Public License
	along with this program; if not, write to the Free Software
	Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA. */

import java.io.File;
import java.util.Hashtable;
import java.util.Enumeration;
import javax.swing.filechooser.FileFilter;

public class UploaderFileFilter extends FileFilter {

	private Hashtable filters = null;
	private String description = null;
	private String fullDescription = null;
	private boolean useExtensionsInDescription = true;

	public UploaderFileFilter() {
	this.filters = new Hashtable();
	}
	
	public boolean accept(File f) {
	if(f != null) {
		if(f.isDirectory()) {
				// Accept directories.  Change when code will allow.
		return true;
		}
		String extension = getExtension(f);
		if(extension != null && filters.get(getExtension(f)) != null) {
		return true;
		};
	}
	return false;
	}

	 public String getExtension(File f) {
	if(f != null) {
		String filename = f.getName();
		int i = filename.lastIndexOf('.');
		if(i>0 && i<filename.length()-1) {
		return filename.substring(i+1).toLowerCase();
		};
	}
	return null;
	}
	 
	public void addExtension(String extension) {
	if(filters == null) {
		filters = new Hashtable(5);
	}
	filters.put(extension.toLowerCase(), this);
	fullDescription = null;
	}
	
	public String getDescription() {
	if(fullDescription == null) {
		if(description == null || isExtensionListInDescription()) {
 		fullDescription = description==null ? "(" : description + " (";
		// build the description from the extension list
		Enumeration extensions = filters.keys();
		if(extensions != null) {
			fullDescription += "." + (String) extensions.nextElement();
			while (extensions.hasMoreElements()) {
			fullDescription += ", ." + (String) extensions.nextElement();
			}
		}
		fullDescription += ")";
		} else {
		fullDescription = description;
		}
	}
	return fullDescription;
	}
	
	public void setDescription(String description) {
	this.description = description;
	fullDescription = null;
	}
	
	public void setExtensionListInDescription(boolean b) {
	useExtensionsInDescription = b;
	fullDescription = null;
	}
	
	public boolean isExtensionListInDescription() {
	return useExtensionsInDescription;
	}
}