public class FibonacciNative
{
public static void main(String[] args) throws DroolsException
{
// <rule-set name="fibonacci" ...>
RuleSet ruleSet = new RuleSet( "fibonacci" );
// <rule name="Bootstrap 1" salience="20">
final Rule bootstrap1Rule = new Rule( "Bootstrap 1" );
bootstrap1Rule.setSalience( 20 );
// Reuse the Java semantics ObjectType
// so Drools can identify the Fibonacci class
final ClassObjectType fibonacciType = new ClassObjectType( Fibonacci.class );
// Build the declaration and specify it as a parameter of the Bootstrap1
// Rule
// <parameter identifier="f">
// <class>org.drools.examples.fibonacci.Fibonacci</class>
// </parameter>
final Declaration fDeclaration = bootstrap1Rule.addParameterDeclaration( "f",
fibonacciType );
// Build and Add the Condition to the Bootstrap1 Rule
// <java:condition>f.getSequence() == 1</java:condition>
final Condition conditionBootstrap1A = new Condition( )
{
public boolean isAllowed(Tuple tuple)
{
Fibonacci f = (Fibonacci) tuple.get( fDeclaration );
return f.getSequence( ) == 1;
}
public Declaration[] getRequiredTupleMembers()
{
return new Declaration[]{fDeclaration};
}
public String toString()
{
return "f.getSequence() == 1";
}
};
bootstrap1Rule.addCondition( conditionBootstrap1A );
// <java:condition>f.getValue() == -1</java:condition>
final Condition conditionBootstrap1B = new Condition( )
{
public boolean isAllowed(Tuple tuple)
{
Fibonacci f = (Fibonacci) tuple.get( fDeclaration );
return f.getValue( ) == -1;
}
public Declaration[] getRequiredTupleMembers()
{
return new Declaration[]{fDeclaration};
}
public String toString()
{
return "f.getValue() == -1";
}
};
bootstrap1Rule.addCondition( conditionBootstrap1B );
// Build and Add the Consequence to the Bootstrap1 Rule
// <java:consequence>
// f.setValue( 1 );
// System.err.println( f.getSequence() + " == " + f.getValue() );
// drools.modifyObject( f );
// </java:consequence>
final Consequence bootstrapConsequence = new Consequence( )
{
public void invoke(Tuple tuple) throws ConsequenceException
{
WorkingMemory workingMemory = tuple.getWorkingMemory( );
Fibonacci f = (Fibonacci) tuple.get( fDeclaration );
f.setValue( 1 );
System.err.println( f.getSequence( ) + " == " + f.getValue( ) );
try
{
workingMemory.modifyObject( tuple.getFactHandleForObject( f ),
f );
}
catch ( FactException e )
{
throw new ConsequenceException( e );
}
}
};
bootstrap1Rule.setConsequence( bootstrapConsequence );
ruleSet.addRule( bootstrap1Rule );
// <rule name="Bootstrap 2">
final Rule bootstrap2Rule = new Rule( "Bootstrap 2" );
// Specify the declaration as a parameter of the Bootstrap2 Rule
// <parameter identifier="f">
// <class>org.drools.examples.fibonacci.Fibonacci</class>
// </parameter>
final Declaration fDeclaration2 = bootstrap2Rule.addParameterDeclaration( "f",
fibonacciType );
// Build and Add the Conditions to the Bootstrap1 Rule
// <java:condition>f.getSequence() == 2</java:condition>
final Condition conditionBootstrap2A = new Condition( )
{
public boolean isAllowed(Tuple tuple)
{
Fibonacci f = (Fibonacci) tuple.get( fDeclaration2 );
return f.getSequence( ) == 2;
}
public Declaration[] getRequiredTupleMembers()
{
return new Declaration[]{fDeclaration2};
}
public String toString()
{
return "f.getSequence() == 2";
}
};
bootstrap2Rule.addCondition( conditionBootstrap2A );
// <java:condition>f.getValue() == -1</java:condition>
final Condition conditionBootstrap2B = new Condition( )
{
public boolean isAllowed(Tuple tuple)
{
Fibonacci f = (Fibonacci) tuple.get( fDeclaration2 );
return f.getValue( ) == -1;
}
public Declaration[] getRequiredTupleMembers()
{
return new Declaration[]{fDeclaration2};
}
public String toString()
{
return "f.getValue() == -1";
}
};
bootstrap2Rule.addCondition( conditionBootstrap2B );
// Build and Add the Consequence to the Bootstrap2 Rule
// <java:consequence>
// f.setValue( 1 );
// System.err.println( f.getSequence() + " == " + f.getValue() );
// drools.modifyObject( f );
// </java:consequence>
final Consequence bootstrapConsequence2 = new Consequence( )
{
public void invoke(Tuple tuple) throws ConsequenceException
{
WorkingMemory workingMemory = tuple.getWorkingMemory( );
Fibonacci f = (Fibonacci) tuple.get( fDeclaration2 );
f.setValue( 1 );
System.err.println( f.getSequence( ) + " == " + f.getValue( ) );
try
{
workingMemory.modifyObject( tuple.getFactHandleForObject( f ),
f );
}
catch ( FactException e )
{
throw new ConsequenceException( e );
}
}
};
bootstrap2Rule.setConsequence( bootstrapConsequence2 );
ruleSet.addRule( bootstrap2Rule );
// <rule name="Recurse" salience="10">
final Rule recurseRule = new Rule( "Recurse" );
recurseRule.setSalience( 10 );
// <parameter identifier="f">
// <class>org.drools.examples.fibonacci.Fibonacci</class>
// </parameter>
final Declaration fDeclarationRecurse = recurseRule.addParameterDeclaration( "f",
fibonacciType );
// <java:condition>f.getValue() == -1</java:condition>
final Condition conditionRecurse = new Condition( )
{
public boolean isAllowed(Tuple tuple)
{
Fibonacci f = (Fibonacci) tuple.get( fDeclarationRecurse );
return f.getValue( ) == -1;
}
public Declaration[] getRequiredTupleMembers()
{
return new Declaration[]{fDeclarationRecurse};
}
public String toString()
{
return "f.getValue() == -1";
}
};
recurseRule.addCondition( conditionRecurse );
// <java:consequence>
// System.err.println( "recurse for " + f.getSequence() );
// drools.assertObject( new Fibonacci( f.getSequence() - 1 ) );
// </java:consequence>
final Consequence recurseConsequence = new Consequence( )
{
public void invoke(Tuple tuple) throws ConsequenceException
{
WorkingMemory workingMemory = tuple.getWorkingMemory( );
Fibonacci f = (Fibonacci) tuple.get( fDeclarationRecurse );
System.err.println( "recurse for " + f.getSequence( ) );
try
{
workingMemory.assertObject( new Fibonacci( f.getSequence( ) - 1 ) );
}
catch ( FactException e )
{
throw new ConsequenceException( e );
}
}
};
recurseRule.setConsequence( recurseConsequence );
ruleSet.addRule( recurseRule );
// <rule name="Calculate">
final Rule calculateRule = new Rule( "Calculate" );
// <parameter identifier="f1">
// <class>org.drools.examples.fibonacci.Fibonacci</class>
// </parameter>
final Declaration f1Declaration = calculateRule.addParameterDeclaration( "f1",
fibonacciType );
// <parameter identifier="f2">
// <class>org.drools.examples.fibonacci.Fibonacci</class>
// </parameter>
final Declaration f2Declaration = calculateRule.addParameterDeclaration( "f2",
fibonacciType );
// <parameter identifier="f3">
// <class>org.drools.examples.fibonacci.Fibonacci</class>
// </parameter>
final Declaration f3Declaration = calculateRule.addParameterDeclaration( "f3",
fibonacciType );
// <java:condition>f2.getSequence() ==
// (f1.getSequence()+1)</java:condition>
final Condition conditionCalculateA = new Condition( )
{
public boolean isAllowed(Tuple tuple)
{
Fibonacci f1 = (Fibonacci) tuple.get( f1Declaration );
Fibonacci f2 = (Fibonacci) tuple.get( f2Declaration );
return f2.getSequence( ) == f1.getSequence( ) + 1;
}
public Declaration[] getRequiredTupleMembers()
{
return new Declaration[]{f1Declaration, f2Declaration};
}
public String toString()
{
return "f2.getSequence() == (f1.getSequence()+1)";
}
};
calculateRule.addCondition( conditionCalculateA );
// <java:condition>f3.getSequence() ==
// (f2.getSequence()+1)</java:condition>
final Condition conditionCalculateB = new Condition( )
{
public boolean isAllowed(Tuple tuple)
{
Fibonacci f2 = (Fibonacci) tuple.get( f2Declaration );
Fibonacci f3 = (Fibonacci) tuple.get( f3Declaration );
return f3.getSequence( ) == f2.getSequence( ) + 1;
}
public Declaration[] getRequiredTupleMembers()
{
return new Declaration[]{f2Declaration, f3Declaration};
}
public String toString()
{
return "f3.getSequence() == (f2.getSequence()+1)";
}
};
calculateRule.addCondition( conditionCalculateB );
// <java:condition>f1.getValue() != -1</java:condition>
final Condition conditionCalculateC = new Condition( )
{
public boolean isAllowed(Tuple tuple)
{
Fibonacci f1 = (Fibonacci) tuple.get( f1Declaration );
return f1.getValue( ) != -1;
}
public Declaration[] getRequiredTupleMembers()
{
return new Declaration[]{f1Declaration};
}
public String toString()
{
return "f1.getValue() != -1";
}
};
calculateRule.addCondition( conditionCalculateC );
// <java:condition>f2.getValue() != -1</java:condition>
final Condition conditionCalculateD = new Condition( )
{
public boolean isAllowed(Tuple tuple)
{
Fibonacci f2 = (Fibonacci) tuple.get( f2Declaration );
return f2.getValue( ) != -1;
}
public Declaration[] getRequiredTupleMembers()
{
return new Declaration[]{f2Declaration};
}
public String toString()
{
return "f2.getValue() != -1";
}
};
calculateRule.addCondition( conditionCalculateD );
// <java:condition>f3.getValue() == -1</java:condition>
final Condition conditionCalculateE = new Condition( )
{
public boolean isAllowed(Tuple tuple)
{
Fibonacci f3 = (Fibonacci) tuple.get( f3Declaration );
return f3.getValue( ) == -1;
}
public Declaration[] getRequiredTupleMembers()
{
return new Declaration[]{f3Declaration};
}
public String toString()
{
return "f3.getValue() == -1";
}
};
calculateRule.addCondition( conditionCalculateE );
// <java:consequence>
// f3.setValue( f1.getValue() + f2.getValue() );
// System.err.println( f3.getSequence() + " == " + f3.getValue() );
// drools.modifyObject( f3 );
// drools.retractObject( f1 );
// </java:consequence>
final Consequence calculateConsequence = new Consequence( )
{
public void invoke(Tuple tuple) throws ConsequenceException
{
WorkingMemory workingMemory = tuple.getWorkingMemory( );
Fibonacci f1 = (Fibonacci) tuple.get( f1Declaration );
Fibonacci f2 = (Fibonacci) tuple.get( f2Declaration );
Fibonacci f3 = (Fibonacci) tuple.get( f3Declaration );
f3.setValue( f1.getValue( ) + f2.getValue( ) );
System.err.println( f3.getSequence( ) + " == " + f3.getValue( ) );
try
{
workingMemory.modifyObject( tuple.getFactHandleForObject( f3 ),
f3 );
workingMemory.retractObject( tuple.getFactHandleForObject( f1 ) );
}
catch ( FactException e )
{
throw new ConsequenceException( e );
}
}
};
calculateRule.setConsequence( calculateConsequence );
ruleSet.addRule( calculateRule );
// Build the RuleSet.
RuleBaseBuilder builder = new RuleBaseBuilder( );
builder.addRuleSet( ruleSet );
RuleBase ruleBase = builder.build( );