DirList.java Source code

Introduction

Here is the source code for DirList.java

Source

// : c12:DirList.java
// Displays directory listing using regular expressions.
// {Args: "D.*\.java"}
// From 'Thinking in Java, 3rd ed.' (c) Bruce Eckel 2002
// www.BruceEckel.com. See copyright notice in CopyRight.txt.

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

public class DirList {
    public static void main(String[] args) {
        File path = new File(".");
        String[] list;
        if (args.length == 0)
            list = path.list();
        else
            list = path.list(new DirFilter(args[0]));
        Arrays.sort(list, new AlphabeticComparator());
        for (int i = 0; i < list.length; i++)
            System.out.println(list[i]);
    }
}

class DirFilter implements FilenameFilter {
    private Pattern pattern;

    public DirFilter(String regex) {
        pattern = Pattern.compile(regex);
    }

    public boolean accept(File dir, String name) {
        // Strip path information, search for regex:
        return pattern.matcher(new File(name).getName()).matches();
    }
} ///:~

class AlphabeticComparator implements Comparator {
    public int compare(Object o1, Object o2) {
        String s1 = (String) o1;
        String s2 = (String) o2;
        return s1.toLowerCase().compareTo(s2.toLowerCase());
    }
} ///:~