Java遍历文件目录的两种方法

时间:2021-06-05 12:44:57

A.不使用递归:

import java.io.File; 
import java.util.LinkedList; 
public class FileSystem { 
    public static void main(String[] args) { 
        long a = System.currentTimeMillis(); 
        LinkedList list = new LinkedList(); 
        File dir = new File("c:\\java\\"); 
        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()); 
        } 
        File tmp; 
        while (!list.isEmpty()) { 
            tmp = list.removeFirst(); 
            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]); 
                    else 
                        System.out.println(file[i].getAbsolutePath()); 
                } 
            } else { 
                System.out.println(tmp.getAbsolutePath()); 
            } 
        } 
        System.out.println(System.currentTimeMillis() - a); 
    } 
} 

B.使用递归:

import java.io.File; 
import java.util.ArrayList; 
public class FileSystem1 { 
    private static ArrayList filelist = new ArrayList(); 
    public static void main(String[] args) { 
        long a = System.currentTimeMillis(); 
        refreshFileList("c:\\java"); 
        System.out.println(System.currentTimeMillis() - a); 
    } 
    public static void refreshFileList(String strPath) { 
        File dir = new File(strPath); 
        File[] files = dir.listFiles(); 
        if (files == null) 
            return; 
        for (int i = 0; i < files.length; i++) { 
            if (files[i].isDirectory()) { 
                refreshFileList(files[i].getAbsolutePath()); 
            } else { 
                String strFileName = files[i].getAbsolutePath().toLowerCase(); 
                System.out.println("---"+strFileName); 
                filelist.add(files[i].getAbsolutePath());                    
            } 
        } 
    } 
} 

结论:经过测试,使用递归的方法B性能相对好一些。