ruleadministratorimpl.java

drools 一个开放源码的规则引擎

package org.drools.jsr94.rules.admin;

/*
 * $Id: RuleAdministratorImpl.java,v 1.15 2006/01/16 01:31:23 michaelneale Exp $
 *
 * Copyright 2002-2004 (C) The Werken Company. All Rights Reserved.
 *
 * Redistribution and use of this software and associated documentation
 * ("Software"), with or without modification, are permitted provided that the
 * following conditions are met:
 *
 * 1. Redistributions of source code must retain copyright statements and
 * notices. Redistributions must also contain a copy of this document.
 *
 * 2. Redistributions in binary form must reproduce the above copyright notice,
 * this list of conditions and the following disclaimer in the documentation
 * and/or other materials provided with the distribution.
 *
 * 3. The name "drools" must not be used to endorse or promote products derived
 * from this Software without prior written permission of The Werken Company.
 * For written permission, please contact [e-mail].
 *
 * 4. Products derived from this Software may not be called "drools" nor may
 * "drools" appear in their names without prior written permission of The Werken
 * Company. "drools" is a registered trademark of The Werken Company.
 *
 * 5. Due credit should be given to The Werken Company.
 * (http://drools.werken.com/).
 *
 * THIS SOFTWARE IS PROVIDED BY THE WERKEN COMPANY AND CONTRIBUTORS ``AS IS''
 * AND ANY EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED. IN NO EVENT SHALL THE WERKEN COMPANY OR ITS CONTRIBUTORS BE
 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 *
 */

import java.util.Map;

import javax.rules.admin.LocalRuleExecutionSetProvider;
import javax.rules.admin.RuleAdministrator;
import javax.rules.admin.RuleExecutionSet;
import javax.rules.admin.RuleExecutionSetDeregistrationException;
import javax.rules.admin.RuleExecutionSetProvider;
import javax.rules.admin.RuleExecutionSetRegisterException;

/**
 * The Drools implementation of the <code>RuleAdministrator</code> interface
 * which is used by rule execution set administrators to load rule execution
 * sets from external sources and create a <code>RuleExecutionSet</code>
 * runtime object. <p/> The <code>RuleAdministrator</code> should be accessed
 * by calling: <p/> <code>
 * RuleServiceProvider ruleServiceProvider =
 *     RuleServiceProvider.newInstance();<br/>
 * RuleAdministrator ruleAdministration =
 *     ruleServiceProvider.getRuleAdministrator();
 * </code>
 * <p/> In an additional step the administrator may also choose to bind the
 * <code>RuleExecutionSet</code> instance to a URI so that it is globally
 * accessible and <code>RuleSession</code>s can be created for the
 * <code>RuleExecutionSet</code> through the RuleRuntime.
 * 
 * @see RuleAdministrator
 * 
 * @author N. Alex Rupp (n_alex <at>codehaus.org)
 * @author <a href="mailto:[e-mail]">thomas diesler </a>
 */
public class RuleAdministratorImpl implements RuleAdministrator {
	private RuleExecutionSetRepository repository;

	/** Default constructor. */
	public RuleAdministratorImpl(RuleExecutionSetRepository repository) {
		super();
		this.repository = repository;
	}

	/**
	 * Returns a <code>RuleExecutionSetProvider</code> implementation.
	 * 
	 * @param properties
	 *            additional properties
	 * 
	 * @return The created <code>RuleExecutionSetProvider</code>.
	 */
	public RuleExecutionSetProvider getRuleExecutionSetProvider(Map properties) {
		return new RuleExecutionSetProviderImpl();
	}

	/**
	 * Returns a <code>LocalRuleExecutionSetProvider</code> implementation.
	 * 
	 * Returns a <code>LocalRuleExecutionSetProvider</code> implementation or
	 * null if this implementation does not support creating a
	 * <code>RuleExecutionSet</code> from non-serializable resources.
	 * 
	 * @param properties
	 *            additional properties
	 * 
	 * @return The created <code>LocalRuleExecutionSetProvider</code>.
	 */
	public LocalRuleExecutionSetProvider getLocalRuleExecutionSetProvider(
			Map properties) {
		return new LocalRuleExecutionSetProviderImpl();
	}

	/**
	 * Registers a <code>RuleExecutionSet</code> and associates it with a
	 * given URI. Once a <code>RuleExecutionSet</code> has been registered it
	 * is accessible to runtime clients through the <code>RuleRuntime</code>.
	 * If a <code>RuleExecutionSet</code> has already been associated with the
	 * URI it should be deregistered (as if
	 * <code>deregisterRuleExecutionSet/</code> had been called) and the URI
	 * should be associated with the new <code>RuleExecutionSet</code>.
	 * 
	 * @param bindUri
	 *            the URI to associate with the <code>RuleExecutionSet</code>.
	 * @param set
	 *            the <code>RuleExecutionSet</code> to associate with the URI
	 * @param properties
	 *            additional properties used to perform the registration
	 * 
	 * @throws RuleExecutionSetRegisterException
	 *             if an error occurred that prevented registration
	 */
	public void registerRuleExecutionSet(String bindUri, RuleExecutionSet set,
			Map properties) throws RuleExecutionSetRegisterException {
		// Note: an existing RuleExecutionSet is simply replaced
		repository.registerRuleExecutionSet(bindUri, set);
	}

	/**
	 * Unregisters a previously registered <code>RuleExecutionSet</code> from
	 * a URI.
	 * 
	 * @param bindUri
	 *            the URI to disassociate with the <code>RuleExecutionSet</code>.
	 * @param properties
	 *            additional properties used to perform the deregistration
	 * 
	 * @throws RuleExecutionSetDeregistrationException
	 *             if an error occurred that prevented unregistration
	 */
	public void deregisterRuleExecutionSet(String bindUri, Map properties)
			throws RuleExecutionSetDeregistrationException {
		if (repository.getRuleExecutionSet(bindUri) == null) {
			throw new RuleExecutionSetDeregistrationException(
					"no execution set bound to: " + bindUri);
		}

		repository.unregisterRuleExecutionSet(bindUri);
	}
}