Android 删除SD卡文件和文件及创建文件夹和文件

package com.jiub.client.mobile.addphoto;
import java.io.File;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import android.graphics.Bitmap;
import android.os.Environment;
import android.util.Log;
public class FileUtils {

  public static String SDPATH = Environment.getExternalStorageDirectory()
      + "/formats/";//获取文件夹
  //保存图片
  public static void saveBitmap(Bitmap bm, String picName) {
    Log.e("", "保存图片");
    Log.d("text", SDPATH);
    try {
      if (!isFileExist("")) {
        File tempf = createSDDir("");
      }
      File f = new File(SDPATH, picName + ".JPEG"); 
      if (f.exists()) {
        f.delete();
      }
      FileOutputStream out = new FileOutputStream(f);
      bm.compress(Bitmap.CompressFormat.JPEG, 90, out);
      out.flush();
      out.close();
      Log.e("", "已经保存");
    } catch (FileNotFoundException e) {
      e.printStackTrace();
    } catch (IOException e) {
      e.printStackTrace();
    }
  }
  public static File createSDDir(String dirName) throws IOException {
    File dir = new File(SDPATH + dirName);
    if (Environment.getExternalStorageState().equals(
        Environment.MEDIA_MOUNTED)) {
      System.out.println("createSDDir:" + dir.getAbsolutePath());
      System.out.println("createSDDir:" + dir.mkdir());
    }
    return dir;
  }
  public static boolean isFileExist(String fileName) {
    File file = new File(SDPATH + fileName);
    file.isFile();
    return file.exists();
  }
  //删除文件
  public static void delFile(String fileName){
    File file = new File(SDPATH + fileName);
    if(file.isFile()){
      file.delete();
        }
    file.exists();
  }
  //删除文件夹和文件夹里面的文件
  public static void deleteDir() {
    File dir = new File(SDPATH);
    if (dir == null || !dir.exists() || !dir.isDirectory())
      return;

    for (File file : dir.listFiles()) {
      if (file.isFile())
        file.delete(); // 删除所有文件
      else if (file.isDirectory())
        deleteDir(); // 递规的方式删除文件夹
    }
    dir.delete();// 删除目录本身
  }
  public static boolean fileIsExists(String path) {
    try {
      File f = new File(path);
      if (!f.exists()) {
        return false;
      }
    } catch (Exception e) {
      return false;
    }
    return true;
  }
}