Pop-Ups and Choosers - The Definitive Guide to Java Swing - page 323

public ExtensionFileFilter(String description, String extensions[]) {
if (description == null) {
// Since no description, use first extension and # of extensions as description
this.description = extensions[0]+"{ "+extensions.length+"} " ;
} else {
this.description = description;
}
// Convert array to lowercase
// Don't alter original entries
this.extensions = (String[])extensions.clone();
toLower(this.extensions);
}
private void toLower(String array[]) {
for (int i=0, n=array.length; i<n; i++) {
array[i] = array[i].toLowerCase();
}
}
public String getDescription() {
return description;
}
// Ignore case, always accept directories
// Character before extension must be a period
public boolean accept(File file) {
if (file.isDirectory()) {
return true;
} else {
String path = file.getAbsolutePath().toLowerCase();
for (int i=0, n=extensions.length; i<n; i++) {
String extension = extensions[i];
if ((path.endsWith(extension) &&
(path.charAt(path.length()-extension.length()-1)) == '.')) {
return true;
}
}
}
return false;
}
}