001/* 002 * CDDL HEADER START 003 * 004 * The contents of this file are subject to the terms of the 005 * Common Development and Distribution License, Version 1.0 only 006 * (the "License"). You may not use this file except in compliance 007 * with the License. 008 * 009 * You can obtain a copy of the license at legal-notices/CDDLv1_0.txt 010 * or http://forgerock.org/license/CDDLv1.0.html. 011 * See the License for the specific language governing permissions 012 * and limitations under the License. 013 * 014 * When distributing Covered Code, include this CDDL HEADER in each 015 * file and include the License file at legal-notices/CDDLv1_0.txt. 016 * If applicable, add the following below this CDDL HEADER, with the 017 * fields enclosed by brackets "[]" replaced with your own identifying 018 * information: 019 * Portions Copyright [yyyy] [name of copyright owner] 020 * 021 * CDDL HEADER END 022 * 023 * 024 * Copyright 2010 Sun Microsystems, Inc. 025 */ 026package org.forgerock.opendj.ldap.controls; 027 028import org.forgerock.opendj.ldap.ByteString; 029 030/** 031 * Controls provide a mechanism whereby the semantics and arguments of existing 032 * LDAP operations may be extended. One or more controls may be attached to a 033 * single LDAP message. A control only affects the semantics of the message it 034 * is attached to. Controls sent by clients are termed 'request controls', and 035 * those sent by servers are termed 'response controls'. 036 * <p> 037 * To determine whether a directory server supports a given control, read the 038 * list of supported controls from the root DSE to get a collection of control 039 * OIDs, and then check for a match: 040 * 041 * <pre> 042 * Connection connection = ...; 043 * Collection<String> supported = 044 * RootDSE.readRootDSE(connection).getSupportedControls(); 045 * 046 * Control control = ...; 047 * String OID = control.getOID(); 048 * if (supported != null && !supported.isEmpty() && supported.contains(OID)) { 049 * // The control is supported. Use it here... 050 * } 051 * </pre> 052 * 053 * @see <a href="http://tools.ietf.org/html/rfc4511">RFC 4511 - Lightweight 054 * Directory Access Protocol (LDAP): The Protocol </a> 055 */ 056public interface Control { 057 058 /** 059 * Returns the numeric OID associated with this control. 060 * 061 * @return The numeric OID associated with this control. 062 */ 063 String getOID(); 064 065 /** 066 * Returns the value, if any, associated with this control. Its format is 067 * defined by the specification of this control. 068 * 069 * @return The value associated with this control, or {@code null} if there 070 * is no value. 071 */ 072 ByteString getValue(); 073 074 /** 075 * Returns {@code true} if this control has a value. In some circumstances 076 * it may be useful to determine if a control has a value, without actually 077 * calculating the value and incurring any performance costs. 078 * 079 * @return {@code true} if this control has a value, or {@code false} if 080 * there is no value. 081 */ 082 boolean hasValue(); 083 084 /** 085 * Returns {@code true} if it is unacceptable to perform the operation 086 * without applying the semantics of this control. 087 * <p> 088 * The criticality field only has meaning in controls attached to request 089 * messages (except UnbindRequest). For controls attached to response 090 * messages and the UnbindRequest, the criticality field SHOULD be 091 * {@code false}, and MUST be ignored by the receiving protocol peer. A 092 * value of {@code true} indicates that it is unacceptable to perform the 093 * operation without applying the semantics of the control. 094 * 095 * @return {@code true} if this control must be processed by the Directory 096 * Server, or {@code false} if it can be ignored. 097 */ 098 boolean isCritical(); 099 100}