/*
 * Created on Sep 10, 2004
 */
package org.sadun.util;

import java.io.File;
import java.io.FilenameFilter;
import java.util.regex.Pattern;

/**
 * A regular-expression based filename filter, which accepts
 * files whose name matches regular expression provided at construction.
 * 
 * @version 1.0
 * @author Cristiano Sadun
 */
public class RegexpFilenameFilter implements FilenameFilter {

	private Pattern pattern;
	private String regexp;
	
	/**
	 * Create a filename filter based on the given regular expression string.
	 * @param regexp the regular expression to use when accepting file names.
	 */
	public RegexpFilenameFilter(String regexp) {
		this.regexp=regexp;
		pattern=Pattern.compile(regexp);
	}

	/**
     * Accept the files whose name matches regular expression provided at construction.
	 * @see java.io.FilenameFilter#accept(java.io.File, java.lang.String)
	 */
	public boolean accept(File dir, String name) {
		return pattern.matcher(name).matches();
	}

	/**
	 * Return the regular expression string used by this filter.
	 * @return the regular expression string used by this filter.
	 */
	public String getPatternString() {
		return regexp;
	}
	
	public String toString() { return "filter matching the regular expression "+regexp; }

}