org.drools.base.mvel
Class MVELAccumulator

java.lang.Object
  org.drools.base.mvel.MVELAccumulator

All Implemented Interfaces:

Externalizable, Serializable, MVELCompileable, Accumulator, Invoker, RuleComponent

public class MVELAccumulator
extends Object
implements MVELCompileable, Accumulator, Externalizable

An MVEL accumulator implementation

See Also:

Serialized Form

Constructor Summary

MVELAccumulator()

MVELAccumulator(MVELCompilationUnit initUnit, MVELCompilationUnit actionUnit, MVELCompilationUnit reverseUnit, MVELCompilationUnit resultUnit)

Method Summary

void	accumulate(Object workingMemoryContext, Object context, Tuple leftTuple, InternalFactHandle handle, Declaration[] declarations, Declaration[] innerDeclarations, WorkingMemory workingMemory) Executes the accumulate (action) code for the given fact handle
void	compile(MVELDialectRuntimeData runtimeData)
Serializable	createContext() Creates the context object for an accumulator session.
Object	createWorkingMemoryContext() Creates and return a context object for each working memory instance
Object	getResult(Object workingMemoryContext, Object context, Tuple leftTuple, Declaration[] declarations, WorkingMemory workingMemory) Gets the result of the accummulation
void	init(Object workingMemoryContext, Object context, Tuple leftTuple, Declaration[] declarations, WorkingMemory workingMemory) Executes the initialization block of code
void	readExternal(ObjectInput in)
void	reverse(Object workingMemoryContext, Object context, Tuple leftTuple, InternalFactHandle handle, Declaration[] declarations, Declaration[] innerDeclarations, WorkingMemory workingMemory) Reverses the accumulate action for the given fact handle
boolean	supportsReverse() Returns true if this accumulator supports operation reversal
void	writeExternal(ObjectOutput out)

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

MVELAccumulator

public MVELAccumulator()

MVELAccumulator

public MVELAccumulator(MVELCompilationUnit initUnit,
                       MVELCompilationUnit actionUnit,
                       MVELCompilationUnit reverseUnit,
                       MVELCompilationUnit resultUnit)

Method Detail

readExternal

public void readExternal(ObjectInput in)
                  throws IOException,
                         ClassNotFoundException

Specified by:

readExternal in interface Externalizable

Throws:

IOException

ClassNotFoundException

writeExternal

public void writeExternal(ObjectOutput out)
                   throws IOException

Specified by:

writeExternal in interface Externalizable

Throws:

IOException

compile

public void compile(MVELDialectRuntimeData runtimeData)

Specified by:

compile in interface MVELCompileable

createContext

public Serializable createContext()

Description copied from interface: Accumulator

Creates the context object for an accumulator session. The context is passed as a parameter to every subsequent accumulator method call in the same session.

Specified by:

createContext in interface Accumulator

Returns:

init

public void init(Object workingMemoryContext,
                 Object context,
                 Tuple leftTuple,
                 Declaration[] declarations,
                 WorkingMemory workingMemory)
          throws Exception

Description copied from interface: Accumulator

Executes the initialization block of code

Specified by:

init in interface Accumulator

leftTuple - tuple causing the rule fire

declarations - previous declarations

Throws:

Exception

accumulate

public void accumulate(Object workingMemoryContext,
                       Object context,
                       Tuple leftTuple,
                       InternalFactHandle handle,
                       Declaration[] declarations,
                       Declaration[] innerDeclarations,
                       WorkingMemory workingMemory)
                throws Exception

Description copied from interface: Accumulator

Executes the accumulate (action) code for the given fact handle

Specified by:

accumulate in interface Accumulator

Throws:

Exception

reverse

public void reverse(Object workingMemoryContext,
                    Object context,
                    Tuple leftTuple,
                    InternalFactHandle handle,
                    Declaration[] declarations,
                    Declaration[] innerDeclarations,
                    WorkingMemory workingMemory)
             throws Exception

Description copied from interface: Accumulator

Reverses the accumulate action for the given fact handle

Specified by:

reverse in interface Accumulator

Throws:

Exception

getResult

public Object getResult(Object workingMemoryContext,
                        Object context,
                        Tuple leftTuple,
                        Declaration[] declarations,
                        WorkingMemory workingMemory)
                 throws Exception

Description copied from interface: Accumulator

Gets the result of the accummulation

Specified by:

getResult in interface Accumulator

Returns:

Throws:

Exception

supportsReverse

public boolean supportsReverse()

Description copied from interface: Accumulator

Returns true if this accumulator supports operation reversal

Specified by:

supportsReverse in interface Accumulator

Returns:

createWorkingMemoryContext

public Object createWorkingMemoryContext()

Description copied from interface: Accumulator

Creates and return a context object for each working memory instance

Specified by:

createWorkingMemoryContext in interface Accumulator

Returns: