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
010     * trunk/opends/resource/legal-notices/OpenDS.LICENSE
011     * or https://OpenDS.dev.java.net/OpenDS.LICENSE.
012     * See the License for the specific language governing permissions
013     * and limitations under the License.
014     *
015     * When distributing Covered Code, include this CDDL HEADER in each
016     * file and include the License file at
017     * trunk/opends/resource/legal-notices/OpenDS.LICENSE.  If applicable,
018     * add the following below this CDDL HEADER, with the fields enclosed
019     * by brackets "[]" replaced with your own identifying information:
020     *      Portions Copyright [yyyy] [name of copyright owner]
021     *
022     * CDDL HEADER END
023     *
024     *
025     *      Copyright 2008 Sun Microsystems, Inc.
026     */
027    package org.opends.server.admin;
028    
029    
030    
031    import java.util.Collection;
032    import java.util.Collections;
033    
034    import org.opends.server.admin.client.ClientConstraintHandler;
035    import org.opends.server.admin.server.ServerConstraintHandler;
036    
037    
038    
039    /**
040     * An interface for enforcing constraints and dependencies between
041     * managed objects and their properties. Constraints express
042     * relationships between managed objects and their properties, for
043     * example:
044     * <ul>
045     * <li>referential integrity: where one managed object references
046     * another a constraint can enforce referential integrity. The
047     * constraint can prevent creation of references to non-existent
048     * managed objects, and also prevent deletion of referenced managed
049     * objects
050     * <li>property dependencies: for example, when a boolean property is
051     * <code>true</code>, one or more additional properties must be
052     * specified. This is useful for features like SSL, which when
053     * enabled, requires that various SSL related configuration options
054     * are specified
055     * <li>property constraints: for example, when an upper limit
056     * property must not have a value which is less than the lower limit
057     * property.
058     * </ul>
059     * On the client-side constraints are enforced immediately before a
060     * write operation is performed. That is to say, immediately before a
061     * new managed object is created, changes to a managed object are
062     * applied, or an existing managed object is deleted.
063     */
064    public abstract class Constraint {
065    
066      /**
067       * Creates a new constraint.
068       */
069      protected Constraint() {
070        // No implementation required.
071      }
072    
073    
074    
075      /**
076       * Gets the client-side constraint handlers which will be used to
077       * enforce this constraint in client applications. The default
078       * implementation is to return an empty set of client constraint
079       * handlers.
080       *
081       * @return Returns the client-side constraint handlers which will be
082       *         used to enforce this constraint in client applications.
083       *         The returned collection must not be <code>null</code>
084       *         but maybe empty (indicating that the constraint can only
085       *         be enforced on the server-side).
086       */
087      public Collection<ClientConstraintHandler> getClientConstraintHandlers() {
088        return Collections.emptySet();
089      }
090    
091    
092    
093      /**
094       * Gets the server-side constraint handlers which will be used to
095       * enforce this constraint within the server. The default
096       * implementation is to return an empty set of server constraint
097       * handlers.
098       *
099       * @return Returns the server-side constraint handlers which will be
100       *         used to enforce this constraint within the server. The
101       *         returned collection must not be <code>null</code> and
102       *         must not be empty, since constraints must always be
103       *         enforced on the server.
104       */
105      public Collection<ServerConstraintHandler> getServerConstraintHandlers() {
106        return Collections.emptySet();
107      }
108    
109    
110    
111      /**
112       * Initializes this constraint. The default implementation is to do
113       * nothing.
114       *
115       * @throws Exception
116       *           If this constraint could not be initialized.
117       */
118      protected void initialize() throws Exception {
119        // Default implementation is to do nothing.
120      }
121    
122    }