importer.java

drools 一个开放源码的规则引擎

package org.drools.spi;

/*
 * $Id: Importer.java,v 1.1 2005/07/26 01:06:32 mproctor Exp $
 *
 * Copyright 2005-2005 (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.io.Serializable;
import java.util.Set;

/**
 * <p>
 * Importer holds a Set of ImportEntries and facilitates the
 * <code> <import/> </code> tag within a <code> <rule-set/> </code> by allowing
 * Classes to be loaded using a specified ClassLoader
 *
 * @author <a href="mailto:[e-mail]"> mark proctor </a>
 */
public interface Importer extends Serializable
{
    /**
     * <p>
     * Adds an ImportEntry to a Set
     *
     * @param importEntry -
     *            the importEntry
     */
    public abstract void addImport(ImportEntry importEntry);

    /**
     * Imports a Class using the given ClassLoader
     *
     * @param cl -
     *            the ClassLoader to use
     * @param className -
     *            the name of the Class to import
     * @return - the loaded class
     * @throws ClassNotFoundException -
     *             Thrown if a Class is not found
     * @throws Error
     *             Thrown is a class is ambiguously imported.
     */
    public abstract Class importClass(ClassLoader cl,
                                      String className) throws ClassNotFoundException, Error;
    /**
     * @return - The Set of ImportEntries
     */
    public Set getImportEntries();

    /**
     * @return - the Set of imports, in text form.
     */
    public Set getImports();

    /**
     * @return - true if no ImportEntries have been added
     */
    public boolean isEmpty();
}