Java遍历文件夹的两种方法(非递归和递归)

import java.io.File;import java.util.LinkedList;public class FileSystem {public static int num; public static void main(String[] args) { long a = System.currentTimeMillis(); //String path="c:"; num=0; String[] lists={"c:","d:"}; /* for(int i=0;i<lists.length;i++){ File file=new File(lists[i]); scanDirRecursion(file); */ for(int i=0;i<lists.length;i++){ scanDirNoRecursion(lists[i]); } System.out.print("文件总数:"+num); System.out.print("总耗时:"); System.out.println(System.currentTimeMillis() – a); }

//非递归 public static void scanDirNoRecursion(String path){ LinkedList list = new LinkedList(); File dir = new File(path); File file[] = dir.listFiles(); for (int i = 0; i < file.length; i++) { if (file[i].isDirectory()) list.add(file[i]); else{ System.out.println(file[i].getAbsolutePath()); num++; } } File tmp; while (!list.isEmpty()) { tmp = (File)list.removeFirst();//首个目录 if (tmp.isDirectory()) { file = tmp.listFiles(); if (file == null) continue; for (int i = 0; i < file.length; i++) { if (file[i].isDirectory()) list.add(file[i]);//目录则加入目录列表，关键 else{ System.out.println(file[i]); num++; } } } else { System.out.println(tmp); num++; } } }

//递归 public static void scanDirRecursion(File file) {try {if (file.canRead()) {if (file.isDirectory()) {String[] files = file.list();if (files != null) {for (int i = 0; i < files.length; i++) {scanDirRecursion(new File(file, files[i]));}}} else {//if (file.getName().endsWith("ppt")) System.out.println(file);num++;}}} catch (Exception e) {e.printStackTrace();}}}测试:

(1)递归： 文件总数:189497 总耗时:39328

(2)非递归：文件总数:189432 总耗时:37469

非递归相对要好

便是不再存在着任何我曾经对你有过的希望。