hive集成kerberos问题1

import java.util.HashSet;
import org.apache.hadoop.hive.ql.parse.ASTNode;
import org.apache.hadoop.hive.ql.parse.AbstractSemanticAnalyzerHook;
import org.apache.hadoop.hive.ql.parse.HiveParser;
import org.apache.hadoop.hive.ql.parse.HiveSemanticAnalyzerHookContext;
import org.apache.hadoop.hive.ql.parse.SemanticException;
import org.apache.hadoop.hive.ql.session.SessionState;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
public class AuthHook extends AbstractSemanticAnalyzerHook {
     static final private Log LOG = LogFactory.getLog(AuthHook.class.getName());
     private static HashSet<String> adminlist = new HashSet<String>() {
          {add("hdfs");}
     };
     private static String adminstr = "hdfs";
     @Override
     public ASTNode preAnalyze(HiveSemanticAnalyzerHookContext context,
               ASTNode ast) throws SemanticException {
          switch (ast.getToken().getType()) {
          case HiveParser.TOK_CREATEDATABASE:
          case HiveParser.TOK_DROPDATABASE:
          case HiveParser.TOK_CREATEROLE:
          case HiveParser.TOK_DROPROLE:
          case HiveParser.TOK_GRANT:
          case HiveParser.TOK_REVOKE:
          case HiveParser.TOK_GRANT_ROLE:
          case HiveParser.TOK_REVOKE_ROLE:
               String userName = null;
               if (SessionState.get() != null && SessionState.get().getAuthenticator() != null) {
                    userName = SessionState.get().getAuthenticator().getUserName();
               }
               LOG.debug("authhook username = "+userName);
               if (!adminlist.contains(userName.toLowerCase())) {
                    throw new SemanticException("User:"+userName
                              + " isn‘t ADMIN, please ask for " + adminstr + ".");
               }
               break;
          default:
               LOG.debug("AST type = "+ast.getToken().getType());
               break;
          }
          return ast;
     }
}