rulesetreader.java

rule engine drools-2.0-beta-18

package org.drools.io;

/*
 * $Id: RuleSetReader.java,v 1.38 2004/11/28 20:01:12 mproctor Exp $
 *
 * Copyright 2001-2003 (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 trademark of The Werken Company.
 *
 * 5. Due credit should be given to The Werken Company. (http://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 org.drools.rule.RuleSet;
import org.drools.smf.Configuration;
import org.drools.smf.DefaultSemanticsRepository;
import org.drools.smf.NoSuchSemanticModuleException;
import org.drools.smf.SemanticModule;
import org.drools.smf.SemanticsRepository;
import org.xml.sax.Attributes;
import org.xml.sax.InputSource;
import org.xml.sax.Locator;
import org.xml.sax.SAXException;
import org.xml.sax.SAXNotRecognizedException;
import org.xml.sax.SAXParseException;
import org.xml.sax.helpers.DefaultHandler;

import javax.xml.parsers.ParserConfigurationException;
import javax.xml.parsers.SAXParser;
import javax.xml.parsers.SAXParserFactory;
import java.io.BufferedInputStream;
import java.io.FileInputStream;
import java.io.InputStream;
import java.io.Reader;
import java.net.URL;
import java.text.MessageFormat;
import java.util.HashMap;
import java.util.Iterator;
import java.util.LinkedList;
import java.util.ListIterator;
import java.util.Map;
import java.util.Set;

/**
 * <code>RuleSet</code> loader.
 *
 * @author <a href="mailto:[e-mail]">bob mcwhirter </a>
 *
 * @version $Id: RuleSetReader.java,v 1.38 2004/11/28 20:01:12 mproctor Exp $
 */
public class RuleSetReader extends DefaultHandler
{
    // ----------------------------------------------------------------------
    //     Constants
    // ----------------------------------------------------------------------

    /** Namespace URI for the general tags. */
    public static final String RULES_NAMESPACE_URI = "http://drools.org/rules";

    private static final String JAXP_SCHEMA_LANGUAGE = "http://java.sun.com/xml/jaxp/properties/schemaLanguage";

    private static final String W3C_XML_SCHEMA = "http://www.w3.org/2001/XMLSchema";

    // ----------------------------------------------------------------------
    //     Instance members
    // ----------------------------------------------------------------------
    /** SAX parser. */
    private SAXParser parser;

    /** Locator for errors. */
    private Locator locator;

    /** Repository of semantic modules. */
    private SemanticsRepository repo;
    //private Map repo;

    /** Stack of configurations. */
    private LinkedList configurationStack;

    /** Current configuration text. */
    private StringBuffer characters2;

    private Map localNameMap;

    private boolean lastWasEndElement;

    private LinkedList parents;

    private Object peer;

    private Object current;

    private RuleSet ruleSet;

    private MessageFormat message = new MessageFormat( "({0}: {1}, {2}): {3}" );

    // ----------------------------------------------------------------------
    //     Constructors
    // ----------------------------------------------------------------------

    /**
     * Construct.
     *
     * <p>
     * Uses the default JAXP SAX parser and the default classpath-based
     * <code>DefaultSemanticModule</code>.
     * </p>
     */
    public RuleSetReader()
    {
        //init
        this.configurationStack = new LinkedList( );
        this.parents = new LinkedList( );

        this.localNameMap = new HashMap( );
        localNameMap.put( "rule-set", new RuleSetHandler( this ) );
        localNameMap.put( "import", new ImportHandler( this ) );
        localNameMap.put( "application-data", new ApplicationDataHandler( this ) );
        localNameMap.put( "rule", new RuleHandler( this ) );
        localNameMap.put( "parameter", new ParameterHandler( this ) );
        //localNameMap.put( "declaration", new DeclarationHandler( this ) );
        localNameMap.put( "class", new ObjectTypeHandler( this ) );
        localNameMap.put( "class-field", new ObjectTypeHandler( this ) );
        localNameMap.put( "condition", new ConditionHandler( this ) );
        localNameMap.put( "duration", new DurationHandler( this ) );
        localNameMap.put( "consequence", new ConsequenceHandler( this ) );

    }

    /**
     * Construct.
     *
     * <p>
     * Uses the default classpath-based <code>DefaultSemanticModule</code>.
     * </p>
     *
     * @param parser
     *            The SAX parser.
     */
    public RuleSetReader( SAXParser parser )
    {
        this( );
        this.parser = parser;
    }

    /**
     * Construct.
     *
     * @param repo
     *            The semantics repository.
     * @param parser
     *            The SAX parser.
     */
    public RuleSetReader( SemanticsRepository repo, SAXParser parser )
    {
        this( parser );
        this.repo = repo;
    }

    /**
     * Construct.
     *
     * @param repo
     *            The semantics repository.
     */
    public RuleSetReader( SemanticsRepository repo )
    {
        this( );
        this.repo = repo;
    }

    // ----------------------------------------------------------------------
    //     Instance methods
    // ----------------------------------------------------------------------

    /**
     * Read a <code>RuleSet</code> from a <code>URL</code>.
     *
     * @param url
     *            The rule-set URL.
     *
     * @return The rule-set.
     *
     * @throws Exception
     *             If an error occurs during the parse.
     */
    public RuleSet read( URL url ) throws Exception
    {
        return read( new InputSource( url.toExternalForm( ) ) );
    }

    /**
     * Read a <code>RuleSet</code> from a <code>Reader</code>.
     *
     * @param reader
     *            The reader containing the rule-set.
     *
     * @return The rule-set.
     *
     * @throws Exception
     *             If an error occurs during the parse.
     */
    public RuleSet read( Reader reader ) throws Exception
    {
        return read( new InputSource( reader ) );
    }

    /**
     * Read a <code>RuleSet</code> from an <code>InputStream</code>.
     *
     * @param inputStream
     *            The input-stream containing the rule-set.
     *
     * @return The rule-set.
     *
     * @throws Exception
     *             If an error occurs during the parse.
     */
    public RuleSet read( InputStream inputStream ) throws Exception
    {
        return read( new InputSource( inputStream ) );
    }

    /**
     * Read a <code>RuleSet</code> from a URL.
     *
     * @param url
     *            The rule-set URL.
     *
     * @return The rule-set.
     *
     * @throws Exception
     *             If an error occurs during the parse.
     */
    public RuleSet read( String url ) throws Exception
    {
        return read( new InputSource( url ) );
    }

    /**
     * Read a <code>RuleSet</code> from an <code>InputSource</code>.
     *
     * @param in
     *            The rule-set input-source.
     *
     * @return The rule-set.
     *
     * @throws Exception
     *             If an error occurs during the parse.
     */
    public RuleSet read( InputSource in ) throws Exception
    {
        SAXParser parser;

        if ( this.parser == null )
        {
            SAXParserFactory factory = SAXParserFactory.newInstance( );
            factory.setNamespaceAware( true );
            String isValidating = System
                    .getProperty( "drools.schema.validating" );
            if ( isValidating == null ) isValidating = "true";

            factory.setValidating( Boolean.valueOf( isValidating )
                    .booleanValue( ) );
            parser = factory.newSAXParser( );
            try
            {
                parser.setProperty( JAXP_SCHEMA_LANGUAGE, W3C_XML_SCHEMA );
            }
            catch ( SAXNotRecognizedException e )
            {
                System.err
                        .println( "Your SAX parser is not JAXP 1.2 compliant." );
            }
        }
        else
        {
            parser = this.parser;
        }

        if ( !parser.isNamespaceAware( ) )
        {
            throw new ParserConfigurationException(
                    "parser must be namespace-aware" );
        }

        if ( this.repo == null )
        {
            try
            {
                this.repo = DefaultSemanticsRepository.getInstance( );
            }
            catch ( Exception e )
            {
                throw new SAXException("Unable to reference a Semantics Repository");
            }
        }

        parser.parse( in, this );

        return this.ruleSet;
    }

    public SemanticsRepository getSemanticsRepository()
    {
        return this.repo;
    }

    void setRuleSet( RuleSet ruleSet )
    {
        this.ruleSet = ruleSet;
    }

    public RuleSet getRuleSet()
    {
        return this.ruleSet;
    }

    /**
     * @see org.xml.sax.ContentHandler
     */
    public void setLocator( Locator locator )
    {
        this.locator = locator;
    }

    /**
     * Get the <code>Locator</code>.
     *
     * @return The locator.
     */
    public Locator getLocator()
    {
        return this.locator;
    }

    public void startDocument()
    {
        this.ruleSet = null;
        this.current = null;
        this.peer = null;
        this.lastWasEndElement = false;
        this.parents.clear();
        this.characters2 = null;
        this.configurationStack.clear();