private String getKey ( String key ) throws IllegalArgumentException { String checkKey = JobHistoryKeys . HADOOP2_TO_HADOOP1_MAPPING . containsKey ( key ) ? JobHistoryKeys . HADOOP2_TO_HADOOP1_MAPPING . get ( key ) : key ; return ( JobHistoryKeys . valueOf ( checkKey ) . toString ( ) ) ; }
maintains compatibility between hadoop 1 . 0 keys and hadoop 2 . 0 keys . It also confirms that this key exists in JobHistoryKeys enum