First you create a class that implements java.io.FilenameFilter and then code the accept() method, then call File.list() with the filter as a parameter. The returned array of strings has all the names that passed through the accept()filter.
import java.io.File;
import java.io.FilenameFilter;
public class Filter implements FilenameFilter {
protected String pattern;
public Filter (String str) {
pattern = str;
}
public boolean accept (File dir, String name) {
return name.toLowerCase().endsWith(pattern.toLowerCase());
}
public static void main (String args[]) {
if (args.length != 1) {
System.err.println
("usage: java Filter ex. java Filter java");
return;
}
Filter nf = new Filter (args[0]);
// current directory
File dir = new File (".");
String[] strs = dir.list(nf);
for (int i = 0; i < strs.length; i++) {
System.out.println (strs[i]);
}
}
}
