/*
* CDDL HEADER START
*
* The contents of this file are subject to the terms of the
* Common Development and Distribution License, Version 1.0 only
* (the "License"). You may not use this file except in compliance
* with the License.
*
* You can obtain a copy of the license at legal-notices/CDDLv1_0.txt
* See the License for the specific language governing permissions
* and limitations under the License.
*
* When distributing Covered Code, include this CDDL HEADER in each
* file and include the License file at legal-notices/CDDLv1_0.txt.
* If applicable, add the following below this CDDL HEADER, with the
* fields enclosed by brackets "[]" replaced with your own identifying
* information:
* Portions Copyright [yyyy] [name of copyright owner]
*
* CDDL HEADER END
*
*
* Copyright 2008 Sun Microsystems, Inc.
*/
/**
* An interface for enforcing constraints and dependencies between managed
* objects and their properties. Constraints express relationships between
* managed objects and their properties, for example:
* <ul>
* <li>referential integrity: where one managed object references another a
* constraint can enforce referential integrity. The constraint can prevent
* creation of references to non-existent managed objects, and also prevent
* deletion of referenced managed objects
* <li>property dependencies: for example, when a boolean property is
* <code>true</code>, one or more additional properties must be specified. This
* is useful for features like SSL, which when enabled, requires that various
* SSL related configuration options are specified
* <li>property constraints: for example, when an upper limit property must not
* have a value which is less than the lower limit property.
* </ul>
* On the client-side constraints are enforced immediately before a write
* operation is performed. That is to say, immediately before a new managed
* object is created, changes to a managed object are applied, or an existing
* managed object is deleted.
*/
public abstract class Constraint {
/**
* Creates a new constraint.
*/
protected Constraint() {
// No implementation required.
}
/**
* Gets the client-side constraint handlers which will be used to enforce
* this constraint in client applications. The default implementation is to
* return an empty set of client constraint handlers.
*
* @return Returns the client-side constraint handlers which will be used to
* enforce this constraint in client applications. The returned
* collection must not be <code>null</code> but maybe empty
* (indicating that the constraint can only be enforced on the
* server-side).
*/
return Collections.emptySet();
}
/**
* Gets the server-side constraint handlers which will be used to enforce
* this constraint within the server. The default implementation is to
* return an empty set of server constraint handlers.
*
* @return Returns the server-side constraint handlers which will be used to
* enforce this constraint within the server. The returned
* collection must not be <code>null</code> and must not be empty,
* since constraints must always be enforced on the server.
*/
return Collections.emptySet();
}
/**
* Initializes this constraint. The default implementation is to do nothing.
*
* @throws Exception
* If this constraint could not be initialized.
*/
// Default implementation is to do nothing.
}
}