Java 目录枚举实用工具

package tools.utils;

import java.io.File;
import java.io.FilenameFilter;
import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;
import java.util.regex.Pattern;

public class Directory {
    public static File[] local(File dir,final String regex){
        return dir.listFiles(new FilenameFilter() {
            Pattern pattern = Pattern.compile(regex);
            @Override
            public boolean accept(File dir, String name) {
                return pattern.matcher(name).matches();
            }
        });
    }
    public static File[] local(String filename,String regex){
        return local(new File(filename),regex);
    }
    public static class TreeInfo implements Iterable<File>{
        public List<File> files = new ArrayList();
        public List<File> dirs = new ArrayList();
        public Iterator iterator(){
            return files.iterator();
        }
        void addAll(TreeInfo treeInfo){
            files.addAll(treeInfo.files);
            dirs.addAll(treeInfo.dirs);
        }
        @Override
        public String toString() {
            return "TreeInfo{" +
                    "files=" + files +
                    ", dirs=" + dirs +
                    '}';
        }
        public static TreeInfo recurseDirs(File startDir,String regex) {
            TreeInfo result = new TreeInfo();
            if (startDir.listFiles() != null){
                for (File file : startDir.listFiles()) {
                    if (file.isDirectory()) {
                        result.dirs.add(file);
                        result.addAll(recurseDirs(file, regex));
                    } else {
                        if (file.getName().matches(regex))
                            result.files.add(file);
                    }
                }
            }
            return result;
        }
        public static TreeInfo walk(String start,String regex){
            return recurseDirs(new File(start),regex);
        }
        public static TreeInfo walk(File start,String regex){
            return recurseDirs(start,regex);
        }
        public static TreeInfo walk(File start){
            return recurseDirs(start,".*");
        }
        public static TreeInfo walk(String start){
            return recurseDirs(new File(start),".*");
        }

        public static void main(String[] args){
            for(File file:local(".",".*")){
                System.out.println(file);
            }
            for(File file:walk("/usr/local/",".*")){
                System.out.println(file);
            }
        }
    }
}

local方法和walk方法都有两个参数，第一个是根目录，第二个是正则表达式.