Mega Code Archive
A simple file filter for a particular file extension
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//revised from prefuse
import java.io.File;
import java.util.ArrayList;
import java.util.Iterator;
import javax.swing.filechooser.FileFilter;
/**
* A simple file filter for a particular file extension.
*
* @author <a href="http://jheer.org">jeffrey heer</a>
*/
public class SimpleFileFilter extends FileFilter {
private ArrayList exts = new ArrayList();
private String desc;
private Object data;
/**
* Create a new SimpleFileFilter.
* @param ext the file extension
* @param desc a description of the file type
*/
public SimpleFileFilter(String ext, String desc) {
addExtension(ext);
this.desc = desc;
}
/**
* Create a new SimpleFileFilter.
* @param ext the file extension
* @param desc a description of the file type
* @param data user-provided attached object
*/
public SimpleFileFilter(String ext, String desc, Object data) {
addExtension(ext);
this.desc = desc;
this.data = data;
}
/**
* Add a file extension to this file filter.
* @param ext the file extension to add
*/
public void addExtension(String ext) {
exts.add(ext.toLowerCase());
}
/**
* @see javax.swing.filechooser.FileFilter#accept(java.io.File)
*/
public boolean accept(File f) {
if ( f == null )
return false;
if ( f.isDirectory() )
return true;
String extension = getExtension(f);
if ( extension == null ) return false;
for ( Iterator iter = exts.iterator(); iter.hasNext(); ) {
String ext = (String)iter.next();
if ( ext.equalsIgnoreCase(extension) )
return true;
}
return false;
}
/**
* Returns the extension for a file or null if there is none
* @param f the input file
* @return the file extension, or null if none
*/
public static String getExtension(File f) {
return (f != null ? getExtension(f.getName()) : null);
}
/**
* Returns the extension for a file or null if there is none
* @param filename the input filename
* @return the file extension, or null if none
*/
public static String getExtension(String filename) {
int i = filename.lastIndexOf('.');
if ( i>0 && i<filename.length()-1 ) {
return filename.substring(i+1).toLowerCase();
} else {
return null;
}
}
/**
* Get a user-provided attached object.
* @return the user-provided attached object
*/
public Object getUserData() {
return data;
}
/**
* @see javax.swing.filechooser.FileFilter#getDescription()
*/
public String getDescription() {
return desc;
}
/**
* Get the first file extension associated with this filter.
* @return the first file extension associated with this filter
*/
public String getExtension() {
return (String)exts.get(0);
}
} // end of class SimpleFileFilter
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