001/*
002 * Copyright 2007-2020 Ping Identity Corporation
003 * All Rights Reserved.
004 */
005/*
006 * Copyright 2007-2020 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) 2008-2020 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.controls;
037
038
039
040import com.unboundid.asn1.ASN1Element;
041import com.unboundid.asn1.ASN1OctetString;
042import com.unboundid.asn1.ASN1Sequence;
043import com.unboundid.ldap.sdk.Control;
044import com.unboundid.ldap.sdk.LDAPException;
045import com.unboundid.ldap.sdk.ResultCode;
046import com.unboundid.util.Debug;
047import com.unboundid.util.NotMutable;
048import com.unboundid.util.StaticUtils;
049import com.unboundid.util.ThreadSafety;
050import com.unboundid.util.ThreadSafetyLevel;
051
052import static com.unboundid.ldap.sdk.controls.ControlMessages.*;
053
054
055
056/**
057 * This class provides an implementation of the LDAP post-read request control
058 * as defined in <A HREF="http://www.ietf.org/rfc/rfc4527.txt">RFC 4527</A>.  It
059 * may be used to request that the server retrieve a copy of the target entry as
060 * it appeared immediately after processing an add, modify, or modify DN
061 * operation.
062 * <BR><BR>
063 * If this control is included in an add, modify, or modify DN request, then the
064 * corresponding response may include a {@link PostReadResponseControl}
065 * containing a version of the entry as it appeared after applying that change.
066 * Note that this response control will only be included if the operation was
067 * successful, so it will not be provided if the operation failed for some
068 * reason (e.g., if the change would have violated the server schema, or if the
069 * requester did not have sufficient permission to perform that operation).
070 * <BR><BR>
071 * The value of this control should contain a set of requested attributes to
072 * include in the entry that is returned.  The server should treat this set of
073 * requested attributes exactly as it treats the requested attributes from a
074 * {@link com.unboundid.ldap.sdk.SearchRequest}.  As is the case with a search
075 * request, if no attributes are specified, then all user attributes will be
076 * included.
077 * <BR><BR>
078 * <H2>Example</H2>
079 * The following example demonstrates the use of the pre-read and post-read
080 * controls.  It will modify an entry to increment the value of the
081 * {@code test-counter} attribute by one, and will use the pre-read and
082 * post-read controls to determine what the previous and updated values are:
083 * <PRE>
084 * // Create a modify request that we can use to increment the value of a
085 * // custom attribute named "test-counter".
086 * ModifyRequest modifyRequest = new ModifyRequest(
087 *      "uid=test.user,ou=People,dc=example,dc=com",
088 *      new Modification(ModificationType.INCREMENT,
089 *           "test-counter", // The attribute to increment.
090 *           "1")); // The amount by which to increment the value.
091 *
092 * // Update the modify request to add both pre-read and post-read request
093 * // controls to see what the entry value was before and after the change.
094 * // We only care about getting the test-counter attribute.
095 * modifyRequest.setControls(
096 *      new PreReadRequestControl("test-counter"),
097 *      new PostReadRequestControl("test-counter"));
098 *
099 * // Process the modify operation in the server.
100 * LDAPResult modifyResult;
101 * try
102 * {
103 *   modifyResult = connection.modify(modifyRequest);
104 *   // If we got here, then the modification should have been successful.
105 * }
106 * catch (LDAPException le)
107 * {
108 *   // This indicates that the operation did not complete successfully.
109 *   modifyResult = le.toLDAPResult();
110 *   ResultCode resultCode = le.getResultCode();
111 *   String errorMessageFromServer = le.getDiagnosticMessage();
112 * }
113 * LDAPTestUtils.assertResultCodeEquals(modifyResult, ResultCode.SUCCESS);
114 *
115 * // Get the pre-read and post-read response controls from the server and
116 * // retrieve the before and after values for the test-counter attribute.
117 * LDAPTestUtils.assertHasControl(modifyResult,
118 *      PreReadResponseControl.PRE_READ_RESPONSE_OID);
119 * PreReadResponseControl preReadResponse =
120 *      PreReadResponseControl.get(modifyResult);
121 * Integer beforeValue =
122 *      preReadResponse.getEntry().getAttributeValueAsInteger("test-counter");
123 *
124 * LDAPTestUtils.assertHasControl(modifyResult,
125 *      PostReadResponseControl.POST_READ_RESPONSE_OID);
126 * PostReadResponseControl postReadResponse =
127 *      PostReadResponseControl.get(modifyResult);
128 * Integer afterValue =
129 *      postReadResponse.getEntry().getAttributeValueAsInteger("test-counter");
130 * </PRE>
131 */
132@NotMutable()
133@ThreadSafety(level=ThreadSafetyLevel.COMPLETELY_THREADSAFE)
134public final class PostReadRequestControl
135       extends Control
136{
137  /**
138   * The OID (1.3.6.1.1.13.2) for the post-read request control.
139   */
140  public static final String POST_READ_REQUEST_OID = "1.3.6.1.1.13.2";
141
142
143
144  /**
145   * The set of requested attributes that will be used if none are provided.
146   */
147  private static final String[] NO_ATTRIBUTES = StaticUtils.NO_STRINGS;
148
149
150
151  /**
152   * The serial version UID for this serializable class.
153   */
154  private static final long serialVersionUID = -4210061989410209462L;
155
156
157
158  // The set of requested attributes to retrieve from the target entry.
159  private final String[] attributes;
160
161
162
163  /**
164   * Creates a new post-read request control that will retrieve the specified
165   * set of attributes from the target entry.  It will be marked critical.
166   *
167   * @param  attributes  The set of attributes to retrieve from the target
168   *                     entry.  It behaves in the same way as the set of
169   *                     requested attributes for a search operation.  If this
170   *                     is empty or {@code null}, then all user attributes
171   *                     will be returned.
172   */
173  public PostReadRequestControl(final String... attributes)
174  {
175    this(true, attributes);
176  }
177
178
179
180  /**
181   * Creates a new post-read request control that will retrieve the specified
182   * set of attributes from the target entry.
183   *
184   * @param  isCritical  Indicates whether this control should be marked
185   *                     critical.
186   * @param  attributes  The set of attributes to retrieve from the target
187   *                     entry.  It behaves in the same way as the set of
188   *                     requested attributes for a search operation.  If this
189   *                     is empty or {@code null}, then all user attributes
190   *                     will be returned.
191   */
192  public PostReadRequestControl(final boolean isCritical,
193                                final String... attributes)
194  {
195    super(POST_READ_REQUEST_OID, isCritical, encodeValue(attributes));
196
197    if (attributes == null)
198    {
199      this.attributes = NO_ATTRIBUTES;
200    }
201    else
202    {
203      this.attributes = attributes;
204    }
205  }
206
207
208
209  /**
210   * Creates a new post-read request control which is decoded from the provided
211   * generic control.
212   *
213   * @param  control  The generic control to be decoded as a post-read request
214   *                  control.
215   *
216   * @throws  LDAPException  If the provided control cannot be decoded as a
217   *                         post-read request control.
218   */
219  public PostReadRequestControl(final Control control)
220         throws LDAPException
221  {
222    super(control);
223
224    final ASN1OctetString value = control.getValue();
225    if (value == null)
226    {
227      throw new LDAPException(ResultCode.DECODING_ERROR,
228                              ERR_POST_READ_REQUEST_NO_VALUE.get());
229    }
230
231    try
232    {
233      final ASN1Element valueElement = ASN1Element.decode(value.getValue());
234      final ASN1Element[] attrElements =
235           ASN1Sequence.decodeAsSequence(valueElement).elements();
236      attributes = new String[attrElements.length];
237      for (int i=0; i < attrElements.length; i++)
238      {
239        attributes[i] =
240             ASN1OctetString.decodeAsOctetString(attrElements[i]).stringValue();
241      }
242    }
243    catch (final Exception e)
244    {
245      Debug.debugException(e);
246      throw new LDAPException(ResultCode.DECODING_ERROR,
247                              ERR_POST_READ_REQUEST_CANNOT_DECODE.get(e), e);
248    }
249  }
250
251
252
253  /**
254   * Encodes the provided information into an octet string that can be used as
255   * the value for this control.
256   *
257   * @param  attributes  The set of attributes to retrieve from the target
258   *                     entry.  It behaves in the same way as the set of
259   *                     requested attributes for a search operation.  If this
260   *                     is empty or {@code null}, then all user attributes
261   *                     will be returned.
262   *
263   * @return  An ASN.1 octet string that can be used as the value for this
264   *          control.
265   */
266  private static ASN1OctetString encodeValue(final String[] attributes)
267  {
268    if ((attributes == null) || (attributes.length == 0))
269    {
270      return new ASN1OctetString(new ASN1Sequence().encode());
271    }
272
273    final ASN1OctetString[] elements = new ASN1OctetString[attributes.length];
274    for (int i=0; i < attributes.length; i++)
275    {
276      elements[i] = new ASN1OctetString(attributes[i]);
277    }
278
279    return new ASN1OctetString(new ASN1Sequence(elements).encode());
280  }
281
282
283
284  /**
285   * Retrieves the set of attributes that will be requested for inclusion in the
286   * entry returned in the response control.
287   *
288   * @return  The set of attributes that will be requested for inclusion in the
289   *          entry returned in the response control, or an empty array if all
290   *          user attributes should be returned.
291   */
292  public String[] getAttributes()
293  {
294    return attributes;
295  }
296
297
298
299  /**
300   * {@inheritDoc}
301   */
302  @Override()
303  public String getControlName()
304  {
305    return INFO_CONTROL_NAME_POST_READ_REQUEST.get();
306  }
307
308
309
310  /**
311   * {@inheritDoc}
312   */
313  @Override()
314  public void toString(final StringBuilder buffer)
315  {
316    buffer.append("PostReadRequestControl(attributes={");
317    for (int i=0; i < attributes.length; i++)
318    {
319      if (i > 0)
320      {
321        buffer.append(", ");
322      }
323      buffer.append('\'');
324      buffer.append(attributes[i]);
325      buffer.append('\'');
326    }
327    buffer.append("}, isCritical=");
328    buffer.append(isCritical());
329    buffer.append(')');
330  }
331}