Android高版本API方法在低版本系统上的兼容性处理

/**
 * Returns the total size in bytes of the partition containing this path.
 * Returns 0 if this path does not exist.
 * 
 * @param path
 * @return -1 means path is null, 0 means path is not exist.
 */
public static long getTotalSpace(File path) {
  if (path == null) {
    return -1;
  }
  return path.getTotalSpace();
}

/**
 * Returns the total size in bytes of the partition containing this path.
 * Returns 0 if this path does not exist.
 * 
 * @param path
 * @return -1 means path is null, 0 means path is not exist.
 */
@TargetApi(Build.VERSION_CODES.GINGERBREAD) 
  // using @TargeApi instead of @SuppressLint("NewApi")
@SuppressWarnings("deprecation")
public static long getTotalSpace(File path) {
  if (path == null) {
    return -1;
  }
  if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.GINGERBREAD) {
    return path.getTotalSpace();
  }
  // implements getTotalSpace() in API lower than GINGERBREAD
  else {
    if (!path.exists()) {
      return 0;
    } else {
      final StatFs stats = new StatFs(path.getPath());
      // Using deprecated method in low API level system, 
      // add @SuppressWarnings("description") to suppress the warning
      return (long) stats.getBlockSize() * (long) stats.getBlockCount();
    }
  }
}