private boolean deleteLastFromFloder(String path) {
    boolean success = false;
    try {
      ArrayList<File> images = new ArrayList<File>();
      getFiles(images, path);
      File latestSavedImage = images.get(0);
      if (latestSavedImage.exists()) {
        for (int i = 1; i < images.size(); i++) {
          File nextFile = images.get(i);
          if (nextFile.lastModified() > latestSavedImage.lastModified()) {
            latestSavedImage = nextFile;
          }
        }

        Log.e("brady", "images = " + latestSavedImage.getAbsolutePath());
        success = latestSavedImage.delete();
      }
    } catch (Exception e) {
      e.printStackTrace();
    }
    return success;
  }

  private void getFiles(ArrayList<File> fileList, String path) {
    File[] allFiles = new File(path).listFiles();
    for (int i = 0; i < allFiles.length; i++) {
      File file = allFiles[i];
      if (file.isFile()) {
        fileList.add(file);
      } else if (!file.getAbsolutePath().contains(".thumnail")) {
        getFiles(fileList, file.getAbsolutePath());
      }
    }
  }

package com.once;
 
import java.io.File;
import java.util.ArrayList;
import java.util.LinkedList;
/**
 * 文件夾遍歷
 * @author once
 *
 */
public class DirTraversal {
   
  //no recursion
  public static LinkedList<File> listLinkedFiles(String strPath) {
    LinkedList<File> list = new LinkedList<File>();
    File dir = new File(strPath);
    File file = dir.listFiles();
    for (int i = 0; i < file.length; i++) {
      if (file.isDirectory())
        list.add(file);
      else
        System.out.println(file.getAbsolutePath());
    }
    File tmp;
    while (!list.isEmpty()) {
      tmp = (File) list.removeFirst();
      if (tmp.isDirectory()) {
        file = tmp.listFiles();
        if (file == null)
          continue;
        for (int i = 0; i < file.length; i++) {
          if (file.isDirectory())
            list.add(file);
          else
            System.out.println(file.getAbsolutePath());
        }
      } else {
        System.out.println(tmp.getAbsolutePath());
      }
    }
    return list;
  }
 
   
  //recursion
  public static ArrayList<File> listFiles(String strPath) {
    return refreshFileList(strPath);
  }
 
  public static ArrayList<File> refreshFileList(String strPath) {
    ArrayList<File> filelist = new ArrayList<File>();
    File dir = new File(strPath);
    File files = dir.listFiles();
 
    if (files == null)
      return null;
    for (int i = 0; i < files.length; i++) {
      if (files.isDirectory()) {
        refreshFileList(files.getAbsolutePath());
      } else {
        if(files.getName().toLowerCase().endsWith("zip"))
          filelist.add(files);
      }
    }
    return filelist;
  }
}