question: private static void checkKey ( String key ) throws MalformedObjectNameException { if ( key == null ) throw new NullPointerException ( "Invalid key (null)" ) ; final int len = key . length ( ) ; if ( len == 0 ) throw new MalformedObjectNameException ( "Invalid key (empty)" ) ; final char [ ] k = key . toCharArray ( ) ; final int endKey = parseKey ( k , 0 ) ; if ( endKey < len ) throw new MalformedObjectNameException ( "Invalid character in value: `" + k [ endKey ] + "'" ) ; }
target:  Check if the supplied key is a valid key.