001/*
002 * Copyright 2018-2020 Ping Identity Corporation
003 * All Rights Reserved.
004 */
005/*
006 * Copyright 2018-2020 Ping Identity Corporation
007 *
008 * Licensed under the Apache License, Version 2.0 (the "License");
009 * you may not use this file except in compliance with the License.
010 * You may obtain a copy of the License at
011 *
012 *    http://www.apache.org/licenses/LICENSE-2.0
013 *
014 * Unless required by applicable law or agreed to in writing, software
015 * distributed under the License is distributed on an "AS IS" BASIS,
016 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
017 * See the License for the specific language governing permissions and
018 * limitations under the License.
019 */
020/*
021 * Copyright (C) 2018-2020 Ping Identity Corporation
022 *
023 * This program is free software; you can redistribute it and/or modify
024 * it under the terms of the GNU General Public License (GPLv2 only)
025 * or the terms of the GNU Lesser General Public License (LGPLv2.1 only)
026 * as published by the Free Software Foundation.
027 *
028 * This program is distributed in the hope that it will be useful,
029 * but WITHOUT ANY WARRANTY; without even the implied warranty of
030 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
031 * GNU General Public License for more details.
032 *
033 * You should have received a copy of the GNU General Public License
034 * along with this program; if not, see <http://www.gnu.org/licenses>.
035 */
036package com.unboundid.ldap.sdk;
037
038
039
040import com.unboundid.util.Debug;
041import com.unboundid.util.ThreadSafety;
042import com.unboundid.util.ThreadSafetyLevel;
043
044
045
046/**
047 * This class provides an implementation of a referral connector that will
048 * retain the exception encountered on the last attempt to establish a
049 * connection for the purpose of following a referral.
050 * <BR><BR>
051 * Note that although this class is technically safe to be used concurrently by
052 * multiple threads in that it won't result in a deadlock or concurrent
053 * modification exception or any other kind of obvious failure, it only retains
054 * a single exception, and only from the last attempt made to establish a
055 * connection for the purpose of following a referral.  If multiple threads try
056 * to use the same instance of this connector concurrently, a call to the
057 * {@link #getExceptionFromLastConnectAttempt()} method may return the result
058 * from the last attempt made on another thread.  It is therefore recommended
059 * that this connector only be used in contexts where it can be safely assumed
060 * that it will not be used concurrently across multiple threads.  For example,
061 * if a connection is not expected to be concurrently shared by multiple
062 * threads, then it may be desirable to use the
063 * {@link LDAPConnection#setReferralConnector(ReferralConnector)} to set a
064 * different instance of this connector for each connection.  Alternately, the
065 * {@link LDAPRequest#setReferralConnector(ReferralConnector)} method may be
066 * used to specify a connector that should be used for an individual request.
067 */
068@ThreadSafety(level=ThreadSafetyLevel.MOSTLY_NOT_THREADSAFE)
069public final class RetainConnectExceptionReferralConnector
070       implements ReferralConnector
071{
072  // The wrapped referral connector that will actually be used to establish the
073  // connection.
074  private final ReferralConnector wrappedReferralConnector;
075
076  // The exception caught in the last attempt to establish a connection for the
077  // purpose of following a referral.
078  private volatile LDAPException connectExceptionFromLastAttempt;
079
080
081
082  /**
083   * Creates a new instance of this referral connector that will use the
084   * connection's default referral handler to actually attempt to establish a
085   * connection.
086   */
087  public RetainConnectExceptionReferralConnector()
088  {
089    this(null);
090  }
091
092
093
094  /**
095   * Creates a new instance of this referral connector that will use the
096   * provided connector to actually attempt to establish a connection.
097   *
098   * @param  wrappedReferralConnector  The referral connector that will be used
099   *                                   to actually attempt to establish a
100   *                                   connection for the purpose of following a
101   *                                   referral.  This may be {@code null} to
102   *                                   use the default referral connector for
103   *                                   the connection on which the referral was
104   *                                   received.
105   */
106  public RetainConnectExceptionReferralConnector(
107              final ReferralConnector wrappedReferralConnector)
108  {
109    this.wrappedReferralConnector = wrappedReferralConnector;
110
111    connectExceptionFromLastAttempt = null;
112  }
113
114
115
116  /**
117   * Retrieves the exception that was caught in the last attempt to establish a
118   * connection for the purpose of following a referral, if any.
119   *
120   * @return  The exception that was caught in the last attempt to establish a
121   *          connection for the purpose of following a referral, or
122   *          {@code null} if the last connection attempt was successful or if
123   *          there have not yet been any connection attempts.
124   */
125  public LDAPException getExceptionFromLastConnectAttempt()
126  {
127    return connectExceptionFromLastAttempt;
128  }
129
130
131
132  /**
133   * {@inheritDoc}
134   */
135  @Override()
136  public LDAPConnection getReferralConnection(final LDAPURL referralURL,
137                                              final LDAPConnection connection)
138                 throws LDAPException
139  {
140    final ReferralConnector connector;
141    if (wrappedReferralConnector == null)
142    {
143      connector = connection.getReferralConnector();
144    }
145    else
146    {
147      connector = wrappedReferralConnector;
148    }
149
150    LDAPException connectException = null;
151    try
152    {
153      return connector.getReferralConnection(referralURL, connection);
154    }
155    catch (final LDAPException e)
156    {
157      Debug.debugException(e);
158      connectException = e;
159      throw e;
160    }
161    finally
162    {
163      connectExceptionFromLastAttempt = connectException;
164    }
165  }
166}