/*

  * Licensed to the Apache Software Foundation (ASF) under one

  * or more contributor license agreements.  See the NOTICE file

  * distributed with this work for additional information

  * regarding copyright ownership.  The ASF licenses this file

  * to you under the Apache License, Version 2.0 (the

  * "License"); you may not use this file except in compliance

  * with the License.  You may obtain a copy of the License at

  *

  *     http://www.apache.org/licenses/LICENSE-2.0

  *

  * Unless required by applicable law or agreed to in writing,

  * software distributed under the License is distributed on an

  * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY

  * KIND, either express or implied.  See the License for the

  * specific language governing permissions and limitations

  * under the License.

  */

 package org.apache.shiro.realm.ldap;

 import java.util.Collection;

 import java.util.HashSet;

 import java.util.Set;

 import javax.naming.NamingEnumeration;

 import javax.naming.NamingException;

 import javax.naming.directory.Attribute;

 import javax.naming.ldap.LdapContext;

 import org.slf4j.Logger;

 import org.slf4j.LoggerFactory;

 /**

  * Utility class providing static methods to make working with LDAP

  * easier.

  *

  * @since 0.2

  */

 public final class LdapUtils {

     /**

      * Private internal log instance.

      */

     private static final Logger log = LoggerFactory.getLogger(LdapUtils.class);

     /**

      * Closes an LDAP context, logging any errors, but not throwing

      * an exception if there is a failure.

      *

      * @param ctx the LDAP context to close.

      */

     public static void closeContext(LdapContext ctx) {

         try {

             if (ctx != null) {

                 ctx.close();

             }

         } catch (NamingException e) {

             log.error("Exception while closing LDAP context. ", e);

         }

     }

     /**

      * Helper method used to retrieve all attribute values from a particular context attribute.

      *

      * @param attr the LDAP attribute.

      * @return the values of the attribute.

      * @throws javax.naming.NamingException if there is an LDAP error while reading the values.

      */

     public static Collection<String> getAllAttributeValues(Attribute attr) throws NamingException {

         Set<String> values = new HashSet<String>();

         NamingEnumeration ne = null;

         try {

             ne = attr.getAll();

             while (ne.hasMore()) {

                 String value = (String) ne.next();

                 values.add(value);

             }

         } finally {

             closeEnumeration(ne);

         }

         return values;

     }

     //added based on SHIRO-127, per Emmanuel's comment [1]

     // [1] https://issues.apache.org/jira/browse/SHIRO-127?focusedCommentId=12891380&page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel#action_12891380

     public static void closeEnumeration(NamingEnumeration ne) {

         try {

             if (ne != null) {

                 ne.close();

             }

         } catch (NamingException e) {

             log.error("Exception while closing NamingEnumeration: ", e);

         }

     }

 }