package org.drools.semantics.java;
/*
* $Id: JavaCondition.java,v 1.15 2005/11/10 05:10:08 mproctor Exp $
*
* Copyright 2002 (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.Serializable;
import javax.naming.ConfigurationException;
import org.drools.rule.Declaration;
import org.drools.rule.Rule;
import org.drools.smf.ConditionInvoker;
import org.drools.smf.Invoker;
import org.drools.smf.SemanticCondition;
import org.drools.smf.SemanticRuleCompiler;
import org.drools.spi.Condition;
import org.drools.spi.ConditionException;
import org.drools.spi.Tuple;
/**
* Java expression semantics <code>Condition</code>.
*
* @author <a href="mailto:bob@werken.com">bob@werken.com </a>
*/
public class JavaCondition
implements
Serializable,
Condition,
SemanticCondition
{
// ------------------------------------------------------------
// Instance members
// ------------------------------------------------------------
protected final String semanticType = "java";
protected final String name;
protected final String expression;
protected final Rule rule;
protected final Declaration[] requiredDeclarations;
protected ConditionInvoker conditionInvoker;
protected final String thrownException = "java.lang.Exception";
// ------------------------------------------------------------
// Constructors
// ------------------------------------------------------------
/**
* Construct.
*
* @param expression
* The expression.
* @param rule
* The rule.
* @throws ConfigurationException
* If an error occurs while attempting to perform configuration.
*/
protected JavaCondition(String name,
String expression,
Declaration[] requiredDeclarations,
Rule rule) throws Exception
{
this.name = name;
this.expression = expression;
this.requiredDeclarations = requiredDeclarations;
this.rule = rule;
}
public String getSemanticType()
{
return semanticType;
}
public boolean isExceptionThrown()
{
return true;
}
public String getThrownException()
{
return this.thrownException;
}
public String getName()
{
return this.name;
}
public String getText()
{
return this.expression;
}
/**
* Retrieve the <code>Declaration</code> s required for evaluating the expression.
*
* @return The required declarations.
*/
public Declaration[] getRequiredTupleMembers()
{
return this.requiredDeclarations;
}
public SemanticRuleCompiler getSemanticRuleCompiler()
{
return JavaSemanticRuleCompiler.getInstance();
}
public void setInvoker(Invoker invoker)
{
this.conditionInvoker = (ConditionInvoker) invoker;
}
/**
* Determine if the supplied <code>Tuple</code> is allowed by this condition.
*
* @param tuple
* The <code>Tuple</code> to test.
*
* @return <code>true</code> if the <code>Tuple</code> passes this condition, else <code>false</code>.
*
* @throws ConditionException
* if an error occurs during filtering.
*/
public boolean isAllowed(Tuple tuple) throws ConditionException
{
try
{
return conditionInvoker.invoke( tuple,
this.requiredDeclarations,
tuple.getWorkingMemory().getApplicationDataMap() );
}
catch ( Exception e )
{
throw new ConditionException( e,
this.rule,
this.expression );
}
}
// ------------------------------------------------------------
public int hashCode()
{
return this.expression.hashCode();
}
public boolean equals(Object object)
{
if ( this == object )
{
return true;
}
if ( object == null || getClass() != object.getClass() )
{
return false;
}
return this.expression.equals( ((JavaCondition) object).expression );
}
public String toString()
{
return "[Condition: " + this.expression + "]";
}
}