| /* | |
| * Copyright (c) 2003, 2020, Oracle and/or its affiliates. All rights reserved. | |
| * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. | |
| * | |
| * This code is free software; you can redistribute it and/or modify it | |
| * under the terms of the GNU General Public License version 2 only, as | |
| * published by the Free Software Foundation. Oracle designates this | |
| * particular file as subject to the "Classpath" exception as provided | |
| * by Oracle in the LICENSE file that accompanied this code. | |
| * | |
| * This code is distributed in the hope that it will be useful, but WITHOUT | |
| * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or | |
| * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License | |
| * version 2 for more details (a copy is included in the LICENSE file that | |
| * accompanied this code). | |
| * | |
| * You should have received a copy of the GNU General Public License version | |
| * 2 along with this work; if not, write to the Free Software Foundation, | |
| * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. | |
| * | |
| * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA | |
| * or visit www.oracle.com if you need additional information or have any | |
| * questions. | |
| */ | |
| package javax.naming.ldap; | |
| import java.io.IOException; | |
| import com.sun.jndi.ldap.Ber; | |
| import com.sun.jndi.ldap.BerEncoder; | |
| /** | |
| * Requests that the results of a search operation be returned by the LDAP | |
| * server in batches of a specified size. | |
| * The requestor controls the rate at which batches are returned by the rate | |
| * at which it invokes search operations. | |
| * <p> | |
| * The following code sample shows how the class may be used: | |
| * <pre>{@code | |
| * | |
| * // Open an LDAP association | |
| * LdapContext ctx = new InitialLdapContext(); | |
| * | |
| * // Activate paged results | |
| * int pageSize = 20; // 20 entries per page | |
| * byte[] cookie = null; | |
| * int total; | |
| * ctx.setRequestControls(new Control[]{ | |
| * new PagedResultsControl(pageSize, Control.CRITICAL) }); | |
| * | |
| * do { | |
| * // Perform the search | |
| * NamingEnumeration results = | |
| * ctx.search("", "(objectclass=*)", new SearchControls()); | |
| * | |
| * // Iterate over a batch of search results | |
| * while (results != null && results.hasMore()) { | |
| * // Display an entry | |
| * SearchResult entry = (SearchResult)results.next(); | |
| * System.out.println(entry.getName()); | |
| * System.out.println(entry.getAttributes()); | |
| * | |
| * // Handle the entry's response controls (if any) | |
| * if (entry instanceof HasControls) { | |
| * // ((HasControls)entry).getControls(); | |
| * } | |
| * } | |
| * // Examine the paged results control response | |
| * Control[] controls = ctx.getResponseControls(); | |
| * if (controls != null) { | |
| * for (int i = 0; i < controls.length; i++) { | |
| * if (controls[i] instanceof PagedResultsResponseControl) { | |
| * PagedResultsResponseControl prrc = | |
| * (PagedResultsResponseControl)controls[i]; | |
| * total = prrc.getResultSize(); | |
| * cookie = prrc.getCookie(); | |
| * } else { | |
| * // Handle other response controls (if any) | |
| * } | |
| * } | |
| * } | |
| * | |
| * // Re-activate paged results | |
| * ctx.setRequestControls(new Control[]{ | |
| * new PagedResultsControl(pageSize, cookie, Control.CRITICAL) }); | |
| * } while (cookie != null); | |
| * | |
| * // Close the LDAP association | |
| * ctx.close(); | |
| * ... | |
| * | |
| * } </pre> | |
| * <p> | |
| * This class implements the LDAPv3 Control for paged-results as defined in | |
| * <a href="https://www.ietf.org/rfc/rfc2696.txt">RFC 2696</a>. | |
| * | |
| * The control's value has the following ASN.1 definition: | |
| * <pre>{@code | |
| * | |
| * realSearchControlValue ::= SEQUENCE { | |
| * size INTEGER (0..maxInt), | |
| * -- requested page size from client | |
| * -- result set size estimate from server | |
| * cookie OCTET STRING | |
| * } | |
| * | |
| * }</pre> | |
| * | |
| * @since 1.5 | |
| * @see PagedResultsResponseControl | |
| * @author Vincent Ryan | |
| */ | |
| public final class PagedResultsControl extends BasicControl { | |
| /** | |
| * The paged-results control's assigned object identifier | |
| * is 1.2.840.113556.1.4.319. | |
| */ | |
| public static final String OID = "1.2.840.113556.1.4.319"; | |
| private static final byte[] EMPTY_COOKIE = new byte[0]; | |
| private static final long serialVersionUID = 6684806685736844298L; | |
| /** | |
| * Constructs a control to set the number of entries to be returned per | |
| * page of results. | |
| * | |
| * @param pageSize The number of entries to return in a page. | |
| * @param criticality If true then the server must honor the control | |
| * and return search results as indicated by | |
| * pageSize or refuse to perform the search. | |
| * If false, then the server need not honor the | |
| * control. | |
| * @throws IOException If an error was encountered while encoding the | |
| * supplied arguments into a control. | |
| */ | |
| public PagedResultsControl(int pageSize, boolean criticality) | |
| throws IOException { | |
| super(OID, criticality, null); | |
| value = setEncodedValue(pageSize, EMPTY_COOKIE); | |
| } | |
| /** | |
| * Constructs a control to set the number of entries to be returned per | |
| * page of results. The cookie is provided by the server and may be | |
| * obtained from the paged-results response control. | |
| * <p> | |
| * A sequence of paged-results can be abandoned by setting the pageSize | |
| * to zero and setting the cookie to the last cookie received from the | |
| * server. | |
| * | |
| * @param pageSize The number of entries to return in a page. | |
| * @param cookie A possibly null server-generated cookie. | |
| * @param criticality If true then the server must honor the control | |
| * and return search results as indicated by | |
| * pageSize or refuse to perform the search. | |
| * If false, then the server need not honor the | |
| * control. | |
| * @throws IOException If an error was encountered while encoding the | |
| * supplied arguments into a control. | |
| */ | |
| public PagedResultsControl(int pageSize, byte[] cookie, | |
| boolean criticality) throws IOException { | |
| super(OID, criticality, null); | |
| if (cookie == null) { | |
| cookie = EMPTY_COOKIE; | |
| } | |
| value = setEncodedValue(pageSize, cookie); | |
| } | |
| /** | |
| * Encodes the paged-results control's value using ASN.1 BER. | |
| * The result includes the BER tag and length for the control's value but | |
| * does not include the control's object identifier and criticality setting. | |
| * | |
| * @param pageSize The number of entries to return in a page. | |
| * @param cookie A non-null server-generated cookie. | |
| * @return A possibly null byte array representing the ASN.1 BER encoded | |
| * value of the LDAP paged-results control. | |
| * @throws IOException If a BER encoding error occurs. | |
| */ | |
| private byte[] setEncodedValue(int pageSize, byte[] cookie) | |
| throws IOException { | |
| // build the ASN.1 encoding | |
| BerEncoder ber = new BerEncoder(10 + cookie.length); | |
| ber.beginSeq(Ber.ASN_SEQUENCE | Ber.ASN_CONSTRUCTOR); | |
| ber.encodeInt(pageSize); | |
| ber.encodeOctetString(cookie, Ber.ASN_OCTET_STR); | |
| ber.endSeq(); | |
| return ber.getTrimmedBuf(); | |
| } | |
| } |