Java非递归遍历树算法---以遍历文件为例

在网上看到的算法，跟之前自己写的一个非遍历算法类似，先记录下来。

非递归：

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);
    }
}

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());
            }
        }
    }
}

来源不详，据说是递归的效率高。。。。心碎

Java非递归遍历树算法---以遍历文件为例