ruleserviceproviderimpl.java

drools 一个开放源码的规则引擎

package org.drools.jsr94.rules;

/*
 * $Id: RuleServiceProviderImpl.java,v 1.12 2006/01/16 01:31:22 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 javax.rules.RuleRuntime;
import javax.rules.RuleServiceProvider;
import javax.rules.admin.RuleAdministrator;

import org.drools.jsr94.rules.admin.RuleAdministratorImpl;
import org.drools.jsr94.rules.admin.RuleExecutionSetRepository;

/**
 * This class provides access to the <code>RuleRuntime</code> and
 * <code>RuleAdministrator</code> implementation supplied by Drools when
 * running under J2SE. <p/> This class should be used in environments without a
 * JNDI provider - typically when writing standalone J2SE clients. Within the
 * J2EE environment the <code>RuleServiceProvider</code> implementation class
 * provided by Drools should be retrieved using a JNDI lookup. <p/> This class
 * should be constructed using the
 * <code>RuleServiceProviderManager.getRuleServiceProvider</code> method.
 * 
 * @see RuleRuntimeImpl
 * @see RuleAdministratorImpl
 * @see RuleServiceProvider
 * @see javax.rules.RuleServiceProviderManager#getRuleServiceProvider(String)
 * 
 * @author <a href="mailto:[e-mail]">thomas diesler </a>
 */
public class RuleServiceProviderImpl extends RuleServiceProvider {
	/** An instance of <code>RuleRuntimeImpl</code>. */
	private RuleRuntime ruleRuntime;

	/** An instance of <code>RuleAdministratorImpl</code>. */
	private RuleAdministrator ruleAdministrator;

	private RuleExecutionSetRepository repository;

	/**
	 * Create a new <code>RuleServiceProviderImpl</code>.
	 */
	public RuleServiceProviderImpl() {
		// no special initialization required
	}

	/**
	 * @return
	 */
	public synchronized RuleExecutionSetRepository getRepository() {
		if (this.repository != null) {
			return this.repository;
		}
		return this.repository = new RuleExecutionSetRepository();
	}


	/**
	 * Returns a class instance of <code>RuleRuntime</code>. Specifically an
	 * instance of the Drools <code>RuleRuntimeImpl</code> is returned.
	 * 
	 * @return an instance of <code>RuleRuntime</code>
	 */
	public synchronized RuleRuntime getRuleRuntime() {
		if (this.ruleRuntime != null) {
			return this.ruleRuntime;
		}
		return this.ruleRuntime = new RuleRuntimeImpl(getRepository());
	}

	/**
	 * Returns a class instance of <code>RuleAdministrator</code>.
	 * Specifically an instance of the Drools <code>RuleAdministratorImpl</code>
	 * is returned.
	 * 
	 * @return an instance of <code>RuleAdministrator</code>
	 */
	public synchronized RuleAdministrator getRuleAdministrator() {
		if (this.ruleAdministrator != null) {
			return this.ruleAdministrator;
		}
		return this.ruleAdministrator = new RuleAdministratorImpl(getRepository());
	}
}