ruleexecutionsetrepository.java

rule engine drools-2.0-beta-18

package org.drools.jsr94.rules.admin;

/*
 * $Id: RuleExecutionSetRepository.java,v 1.10 2004/11/27 00:59:54 dbarnett 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.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

import javax.rules.admin.RuleExecutionSet;

/**
 * Stores the registered <code>RuleExecutionSet</code> objects.
 *
 * @author <a href="mailto:[e-mail]">thomas diesler </a>
 */
public final class RuleExecutionSetRepository
{
    /** The Singleton instance of the repository. */
    private static RuleExecutionSetRepository REPOSITORY;

    /** Holds the registered <code>RuleExecutionSet</code> objects. */
    private Map map = new HashMap( );

    /** Private constructor; use <code>getInstance</code> instead. */
    private RuleExecutionSetRepository( )
    {
        // Hide the constructor.
    }

    /**
     * Gets the Singleton instance of a <code>RuleExecutionSetRepository</code>.
     *
     * @return The Singleton instance of the repository.
     */
    public static synchronized RuleExecutionSetRepository getInstance( )
    {
        if ( RuleExecutionSetRepository.REPOSITORY != null )
        {
            return RuleExecutionSetRepository.REPOSITORY;
        }
        return RuleExecutionSetRepository.REPOSITORY =
            new RuleExecutionSetRepository( );
    }

    /**
     * Retrieves a <code>List</code> of the URIs that currently have
     * <code>RuleExecutionSet</code>s associated with them.
     *
     * An empty list is returned is there are no associations.
     *
     * @return a <code>List</code> of the URIs that currently have
     *         <code>RuleExecutionSet</code>s associated with them.
     */
    public List getRegistrations( )
    {
        List list = new ArrayList( );
        list.addAll( this.map.keySet( ) );
        return list;
    }

    /**
     * Get the <code>RuleExecutionSet</code> bound to this URI, or return
     * <code>null</code>.
     *
     * @param bindUri the URI associated with the wanted
     *        <code>RuleExecutionSet</code>.
     *
     * @return the <code>RuleExecutionSet</code> bound to the given URI.
     */
    public RuleExecutionSet getRuleExecutionSet( String bindUri )
    {
        return ( RuleExecutionSet ) this.map.get( bindUri );
    }

    /**
     * Register a <code>RuleExecutionSet</code> under the given URI.
     *
     * @param bindUri the URI to associate with the
     *        <code>RuleExecutionSet</code>.
     * @param ruleSet the <code>RuleExecutionSet</code> to associate with the
     *        URI
     */
    public void registerRuleExecutionSet(
        String bindUri, RuleExecutionSet ruleSet )
    {
        if ( bindUri == null )
        {
            throw new NullPointerException( "bindUri cannot be null" );
        }
        if ( ruleSet == null )
        {
            throw new NullPointerException( "ruleSet cannot be null" );
        }
        this.map.put( bindUri, ruleSet );
    }

    /**
     * Unregister a <code>RuleExecutionSet</code> from the given URI.
     *
     * @param bindUri the URI to disassociate with the
     *        <code>RuleExecutionSet</code>.
     */
    public void unregisterRuleExecutionSet( String bindUri )
    {
        if ( bindUri == null )
        {
            throw new NullPointerException( "bindUri cannot be null" );
        }
        this.map.remove( bindUri );
    }
}