StorageUtil.java

public class StorageUtil {

	private StorageUtil() {
	}

	public static Context mContext;

	public static void init(Context context) {
		mContext = context;
	}

	/**
	 * 判断外存储是否可写
	 * 
	 * @return
	 */
	public static boolean isExternalStorageWritable() {
		String state = Environment.getExternalStorageState();
		return Environment.MEDIA_MOUNTED.equals(state);
	}

	/**
	 * 获取可用sd空间大小
	 * 
	 * @param context
	 *            应用程序上下文
	 * @return
	 */
	@SuppressWarnings("deprecation")
	public static long getAvailableSize() {
		StatFs statfs = new StatFs(Environment.getExternalStorageDirectory().getAbsolutePath());
		long blocks = statfs.getAvailableBlocks();
		long size = statfs.getBlockSize();
		return blocks * size;
	}

	/**
	 * sd卡空间是否够用
	 * 
	 * @param context
	 *            应用程序上下文
	 * @param contentLength
	 *            文件大小
	 * @return
	 */
	public static boolean isSaveable(int contentLength) {
		long avaliable = getAvailableSize();
		return avaliable > contentLength ? true : false;
	}

	/**
	 * 存储完文件后，sd存储空间是否处于快用完状态
	 * 
	 * @param context
	 *            应用程序上下文
	 * @param contentLength
	 *            文件大小
	 * @return
	 */
	public static boolean isWeakSaveable(int contentLength) {
		return getAvailableSize() - 30 * 1024 * 1024 < contentLength ? true : false;
	}

	/**
	 * Get a file path from a Uri. This will get the the path for Storage Access Framework Documents, as well as the _data field for the MediaStore and other file-based ContentProviders.
	 * 
	 * @param context
	 *            The context.
	 * @param uri
	 *            The Uri to query.
	 */
	public static String getPath(final Context context, final Uri uri) {

		final boolean isKitKat = Build.VERSION.SDK_INT >= Build.VERSION_CODES.KITKAT;

		// DocumentProvider
		if (isKitKat && DocumentsContract.isDocumentUri(context, uri)) {
			// ExternalStorageProvider
			if (isExternalStorageDocument(uri)) {
				final String docId = DocumentsContract.getDocumentId(uri);
				final String[] split = docId.split(":");
				final String type = split[0];

				if ("primary".equalsIgnoreCase(type)) {
					return Environment.getExternalStorageDirectory() + "/" + split[1];
				}
				// TODO handle non-primary volumes
			}
			// DownloadsProvider
			else if (isDownloadsDocument(uri)) {

				final String id = DocumentsContract.getDocumentId(uri);
				final Uri contentUri = ContentUris.withAppendedId(Uri.parse("content://downloads/public_downloads"), Long.valueOf(id));

				return getDataColumn(context, contentUri, null, null);
			}
			// MediaProvider
			else if (isMediaDocument(uri)) {
				final String docId = DocumentsContract.getDocumentId(uri);
				final String[] split = docId.split(":");
				final String type = split[0];

				Uri contentUri = null;
				if ("image".equals(type)) {
					contentUri = MediaStore.Images.Media.EXTERNAL_CONTENT_URI;
				} else if ("video".equals(type)) {
					contentUri = MediaStore.Video.Media.EXTERNAL_CONTENT_URI;
				} else if ("audio".equals(type)) {
					contentUri = MediaStore.Audio.Media.EXTERNAL_CONTENT_URI;
				}

				final String selection = "_id=?";
				final String[] selectionArgs = new String[] { split[1] };

				return getDataColumn(context, contentUri, selection, selectionArgs);
			}
		}
		// MediaStore (and general)
		else if ("content".equalsIgnoreCase(uri.getScheme())) {
			return getDataColumn(context, uri, null, null);
		}
		// File
		else if ("file".equalsIgnoreCase(uri.getScheme())) {
			return uri.getPath();
		}

		return null;
	}

	/**
	 * Get the value of the data column for this Uri. This is useful for MediaStore Uris, and other file-based ContentProviders.
	 * 
	 * @param context
	 *            The context.
	 * @param uri
	 *            The Uri to query.
	 * @param selection
	 *            (Optional) Filter used in the query.
	 * @param selectionArgs
	 *            (Optional) Selection arguments used in the query.
	 * @return The value of the _data column, which is typically a file path.
	 */
	public static String getDataColumn(Context context, Uri uri, String selection, String[] selectionArgs) {
		Cursor cursor = null;
		final String[] projection = { MediaStore.MediaColumns.DATA };
		try {
			cursor = context.getContentResolver().query(uri, projection, selection, selectionArgs, null);
			if (cursor != null && cursor.moveToFirst()) {
				final int column_index = cursor.getColumnIndexOrThrow(MediaStore.MediaColumns.DATA);
				return cursor.getString(column_index);
			}
		} finally {
			if (cursor != null) {
				cursor.close();
			}
		}
		return null;
	}

	/**
	 * @param uri
	 *            The Uri to check.
	 * @return Whether the Uri authority is ExternalStorageProvider.
	 */
	public static boolean isExternalStorageDocument(Uri uri) {
		return "com.android.externalstorage.documents".equals(uri.getAuthority());
	}

	/**
	 * @param uri
	 *            The Uri to check.
	 * @return Whether the Uri authority is DownloadsProvider.
	 */
	public static boolean isDownloadsDocument(Uri uri) {
		return "com.android.providers.downloads.documents".equals(uri.getAuthority());
	}

	/**
	 * @param uri
	 *            The Uri to check.
	 * @return Whether the Uri authority is MediaProvider.
	 */
	public static boolean isMediaDocument(Uri uri) {
		return "com.android.providers.media.documents".equals(uri.getAuthority());
	}

	public static boolean deleteDirectory(String filePath) {
		if (null == filePath) {
			return false;
		}
		File file = new File(filePath);
		if (file == null || !file.exists()) {
			return false;
		}
		if (file.isDirectory()) {
			File[] list = file.listFiles();
			for (int i = 0; i < list.length; i++) {
				if (list[i].isDirectory()) {
					deleteDirectory(list[i].getAbsolutePath());
				} else {
					list[i].delete();
				}
			}
		}
		file.delete();
		return true;
	}

	public static boolean createDirectory(String filePath) {
		if (null == filePath) {
			return false;
		}
		File file = new File(filePath);
		if (file.exists()) {
			return true;
		}
		file.mkdirs();
		return true;
	}

	public static boolean deleteFile(String filepath) {
		File file = new File(filepath);
		if (file.exists()) {
			return file.delete();
		}
		return false;
	}
}