Android获取SDcard目录及创建文件夹的方法

 public static String getSDPath() {
    File sdDir = null;
    boolean sdCardExist = Environment.getExternalStorageState().equals(android.os.Environment.MEDIA_MOUNTED);// 判断sd卡是否存在
    if (sdCardExist) {
      sdDir = Environment.getExternalStorageDirectory();// 获取跟目录
    }
    return sdDir.toString();
  }

public static String mkdirs(String path) {
    String sdcard = getSDPath();
    if (path.indexOf(getSDPath()) == -1) {
      path = sdcard + (path.indexOf("/") == 0 ? "" : "/") + path;
    }
    File destDir = new File(path);
    if (!destDir.exists()) {
      path = makedir(path);
      if (path == null) {
        return null;
      }
    }
    return path;
  }

  private static String makedir(String path) {
    String sdPath = getSDPath();
    String[] dirs = path.replace(sdPath, "").split("/");
    StringBuffer filePath = new StringBuffer(sdPath);
    for (String dir : dirs) {
      if (!"".equals(dir) && !dir.equals(sdPath)) {
        filePath.append("/").append(dir);
        File destDir = new File(filePath.toString());
        if (!destDir.exists()) {
          boolean b = destDir.mkdirs();
          if (!b) {
            return null;
          }
        }
      }
    }
    return filePath.toString();
  }

<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
<!-- 在sdcard中创建/删除文件的权限 -->
<uses-permission android:name="android.permission.MOUNT_UNMOUNT_FILESYSTEMS" />

ImageView view5 = findView(R.id.imageview2);
view5.setImageBitmap(ImageUtils.getLoacalBitmap("/storage/sdcard1/myimage/20160807.jpg"));

public static Bitmap getLoacalBitmap(String url) {
    try {
       FileInputStream fis = new FileInputStream(url);
       return BitmapFactory.decodeStream(fis);
    } catch (FileNotFoundException e) {
       //这里应显示默认图片，如图片无法显示等；从应用资源图片中选取
       return null;
    }
  }