android根据Uri得到图片文件的真实路径

/**
* Try to return the absolute file path from the given Uri
*
* @param context
* @param uri
* @return the file path or null
*/
public static String getRealFilePath( final Context context, final Uri uri ) {
if ( null == uri ) return null;
final String scheme = uri.getScheme();
String data = null;
if ( scheme == null )
data = uri.getPath();
else if ( ContentResolver.SCHEME_FILE.equals( scheme ) ) {
data = uri.getPath();
} else if ( ContentResolver.SCHEME_CONTENT.equals( scheme ) ) {
Cursor cursor = context.getContentResolver().query( uri, new String[] { ImageColumns.DATA }, null, null, null );
if ( null != cursor ) {
if ( cursor.moveToFirst() ) {
int index = cursor.getColumnIndex( ImageColumns.DATA );
if ( index > -1 ) {
data = cursor.getString( index );
}
}
cursor.close();
}
}
return data;
}