java IO复习(三)

package com.zyw.io;

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;

/**
 * 目录实用工具
 * from think in java
 */
public class Directory {
    public static File[] local(File dir,final String regex){
      return dir.listFiles(new FilenameFilter() {
         private Pattern pattern=Pattern.compile(regex);
         @Override
         public boolean accept(File dir, String name) {
             return pattern.matcher(new File(name).getName()).matches();
         }
     });
    }
    public static File[] local(String path,final String regex){
        return local(new File(path),regex);
    }
    public static class TreeInfo implements Iterable<File>{
        public List<File> files=new ArrayList<File>();
        public List<File> dirs=new ArrayList<File>();
        @Override
        public Iterator<File> iterator() {
            return files.iterator();
        }
        void addAll(TreeInfo other){
            files.addAll(other.files);
            dirs.addAll(other.dirs);
        }
        public String toString(){
            return "dirs: "+PPrint.pformat(dirs)+"\n\nfiles: "+PPrint.pformat(files);
        }
    }
    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),".");}
    static TreeInfo recurseDirs(File startDir,String regex){
        TreeInfo result=new TreeInfo();
        for(File item: startDir.listFiles()){
            if(item.isDirectory()){
                result.dirs.add(item);
                result.addAll(recurseDirs(item,regex));//以新的目录为起点
            }else {
                if(item.getName().matches(regex))
                    result.files.add(item);
            }
        }
        return result;
    }
    public  static void main(String args[]){
        System.out.println(walk("G:\\zyw",".*\\.class"));
    }
}

package com.zyw.io;

import java.util.Arrays;
import java.util.Collection;

/**
 * 打印工具
 */
public class PPrint {
    public static String pformat(Collection<?> c){
        if(c.size()==0) return "[]";
        StringBuilder result=new StringBuilder("[");
        for(Object elem:c){
            if(c.size()!=1)
                result.append("\n ");
            result.append(elem);
        }
        if(c.size()!=1) result.append("\n");
            result.append("]");
        return result.toString();
    }
    public static void pprint(Collection<?> c){
        System.out.println(pformat(c));
    }
    public static void pprint(Object[] c){
        System.out.println(pformat(Arrays.asList(c)));
    }
}