package org.drools.jsr94.rules.admin;
/*
* $Id: RuleExecutionSetProviderImpl.java,v 1.19 2005/02/04 02:13:38 mproctor 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 bob@werken.com.
*
* 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.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.Reader;
import java.io.Serializable;
import java.net.URL;
import java.util.Map;
import javax.rules.admin.RuleExecutionSet;
import javax.rules.admin.RuleExecutionSetCreateException;
import javax.rules.admin.RuleExecutionSetProvider;
import javax.xml.transform.Source;
import javax.xml.transform.Transformer;
import javax.xml.transform.TransformerException;
import javax.xml.transform.TransformerFactory;
import javax.xml.transform.dom.DOMSource;
import javax.xml.transform.sax.SAXResult;
import org.drools.io.RuleSetReader;
import org.drools.rule.RuleSet;
import org.drools.smf.DefaultSemanticsRepository;
import org.drools.smf.SemanticsReaderException;
import org.w3c.dom.Element;
/**
* The Drools implementation of the <code>RuleExecutionSetProvider</code>
* interface which defines <code>RuleExecutionSet</code> creation methods for
* defining <code>RuleExecutionSet</code>s from potentially serializable
* resources.
*
* @see RuleExecutionSetProvider
*
* @author N. Alex Rupp (n_alex <at>codehaus.org)
* @author <a href="mailto:thomas.diesler@softcon-itec.de">thomas diesler </a>
*/
public class RuleExecutionSetProviderImpl implements RuleExecutionSetProvider
{
/**
* Creates a <code>RuleExecutionSet</code> implementation from an XML
* Document and additional Drools-specific properties. A Drools-specific
* rule execution set is read from the supplied XML Document.
*
* @param ruleExecutionSetElement the XML element that is the source of the
* rule execution set
* @param properties additional properties used to create the
* <code>RuleExecutionSet</code> implementation.
* May be <code>null</code>.
*
* @throws RuleExecutionSetCreateException on rule execution set creation
* error.
*
* @return The created <code>RuleExecutionSet</code>.
*/
public RuleExecutionSet createRuleExecutionSet(
Element ruleExecutionSetElement, Map properties )
throws RuleExecutionSetCreateException
{
// Prepare the DOM source
Source source = new DOMSource( ruleExecutionSetElement );
// Create a reader to handle the SAX events
RuleSetReader reader;
try
{
reader =
new RuleSetReader( DefaultSemanticsRepository.getInstance( ) );
}
catch ( SemanticsReaderException e )
{
throw new RuleExecutionSetCreateException(
"Couldn't get an instance of the DefaultSemanticsRepository: "
+ e );
}
catch ( IOException e )
{
throw new RuleExecutionSetCreateException(
"Couldn't get an instance of the DefaultSemanticsRepository: "
+ e );
}
try
{
// Prepare the result
SAXResult result = new SAXResult( reader );
// Create a transformer
Transformer xformer =
TransformerFactory.newInstance( ).newTransformer( );
// Traverse the DOM tree
xformer.transform( source, result );
}
catch ( TransformerException e )
{
throw new RuleExecutionSetCreateException(
"could not create RuleExecutionSet: " + e );
}
RuleSet ruleSet = reader.getRuleSet( );
LocalRuleExecutionSetProviderImpl localRuleExecutionSetProvider =
new LocalRuleExecutionSetProviderImpl( );
return localRuleExecutionSetProvider.createRuleExecutionSet(
ruleSet, properties );
}
/**
* Creates a <code>RuleExecutionSet</code> implementation from a
* Drools-specific Abstract Syntax Tree (AST) representation and
* Drools-specific properties.
* <p/>
* This method accepts a <code>org.drools.RuleBase</code> object as its
* vendor-specific AST representation.
*
* @param ruleExecutionSetAst the Drools representation of a
* rule execution set
* @param properties additional properties used to create the
* <code>RuleExecutionSet</code> implementation.
* May be <code>null</code>.
*
* @throws RuleExecutionSetCreateException on rule execution set creation
* error.
*
* @return The created <code>RuleExecutionSet</code>.
*/
public RuleExecutionSet createRuleExecutionSet(
Serializable ruleExecutionSetAst, Map properties )
throws RuleExecutionSetCreateException
{
if ( ruleExecutionSetAst instanceof RuleSet )
{
LocalRuleExecutionSetProviderImpl localRuleExecutionSetProvider =
new LocalRuleExecutionSetProviderImpl( );
return localRuleExecutionSetProvider.createRuleExecutionSet(
ruleExecutionSetAst, properties );
}
else
{
throw new IllegalArgumentException( "Serializable object must be "
+ "an instance of org.drools.rule.RuleSet. It was "
+ ruleExecutionSetAst.getClass( ).getName( ) );
}
}
/**
* Creates a <code>RuleExecutionSet</code> implementation from a URI.
* The URI is opaque to the specification and may be used to refer to the
* file system, a database, or Drools-specific datasource.
*
* @param ruleExecutionSetUri the URI to load the rule execution set from
* @param properties additional properties used to create the
* <code>RuleExecutionSet</code> implementation.
* May be <code>null</code>.
*
* @throws RuleExecutionSetCreateException on rule execution set creation
* error.
* @throws IOException if an I/O error occurs while accessing the URI
*
* @return The created <code>RuleExecutionSet</code>.
*/
public RuleExecutionSet createRuleExecutionSet(
String ruleExecutionSetUri, Map properties )
throws RuleExecutionSetCreateException, IOException
{
InputStream in = null;
try
{
LocalRuleExecutionSetProviderImpl localRuleExecutionSetProvider =
new LocalRuleExecutionSetProviderImpl( );
in = new URL( ruleExecutionSetUri ).openStream( );
Reader reader = new InputStreamReader( in );
return localRuleExecutionSetProvider.createRuleExecutionSet(
reader, properties );
}
catch ( IOException ex )
{
throw ex;
}
finally
{
if ( in != null )
{
in.close( );
}
}
}
}