ImageUtil工具类

public class ImageUtil {
    public static Intent getGalleryIntent(Intent intent)
    {
        /**19之后的系统相册的图片都存在于MediaStore数据库中；19之前的系统相册中可能包含不存在与数据库中的图片，所以如果是19之上的系统
         * 跳转到19之前的系统相册选择了一张不存在与数据库中的图片，解析uri时就可能会出现null*/
        if (Build.VERSION.SDK_INT < 19) {
            intent.setAction(Intent.ACTION_GET_CONTENT);
            intent.setType("image/*");
        } else {
            intent = new Intent(Intent.ACTION_PICK, MediaStore.Images.Media.EXTERNAL_CONTENT_URI);
            intent.setDataAndType(MediaStore.Images.Media.EXTERNAL_CONTENT_URI,"image/*");
        }
        return intent;
    }

    /**
     * 专为Android4.4设计的从Uri获取文件绝对路径，以前的方法已不好使
     * 可以用在  解析 uri 数据的地方（相册回传数据）
     */
    @RequiresApi(api = Build.VERSION_CODES.KITKAT)
    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];

                }

            }
            // 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 column = "_data";
        final String[] projection = {column};

        try
        {
            cursor = context.getContentResolver().query(uri, projection, selection, selectionArgs,
                    null);
            if (cursor != null && cursor.moveToFirst())
            {
                final int column_index = cursor.getColumnIndexOrThrow(column);
                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());

    }

}