org.drools.base.accumulators
Class CollectListAccumulateFunction

java.lang.Object
  org.drools.base.accumulators.CollectListAccumulateFunction

All Implemented Interfaces:

Externalizable, Serializable, org.drools.runtime.rule.AccumulateFunction, org.drools.runtime.rule.TypedAccumulateFunction

public class CollectListAccumulateFunction
extends Object
implements AccumulateFunction

An implementation of an accumulator capable of collecting lists of values. This is similar to the "collect" CE, but allows us to collect any value, not only facts.

Example:

 rule "List employee names"
 when
     $names : List() from accumulate(
             Employee( $n : firstName, $l : lastName ),
             collectList( $n + " " + $l ) )
 then
     // do something
 end
 

The list accepts duplications and the order of the elements in the list is not guaranteed.

See Also:

Serialized Form

Nested Class Summary

static class

CollectListAccumulateFunction.CollectListData

Constructor Summary

CollectListAccumulateFunction()

Method Summary

void	accumulate(Serializable context, Object value)
Serializable	createContext()
Object	getResult(Serializable context)
Class<?>	getResultType()
void	init(Serializable context)
void	readExternal(ObjectInput in)
void	reverse(Serializable context, Object value)
boolean	supportsReverse()
void	writeExternal(ObjectOutput out)

Methods inherited from class java.lang.Object

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

Constructor Detail

CollectListAccumulateFunction

public CollectListAccumulateFunction()

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

createContext

public Serializable createContext()

Specified by:

createContext in interface org.drools.runtime.rule.AccumulateFunction

init

public void init(Serializable context)
          throws Exception

Specified by:

init in interface org.drools.runtime.rule.AccumulateFunction

Throws:

Exception

accumulate

public void accumulate(Serializable context,
                       Object value)

Specified by:

accumulate in interface org.drools.runtime.rule.AccumulateFunction

reverse

public void reverse(Serializable context,
                    Object value)
             throws Exception

Specified by:

reverse in interface org.drools.runtime.rule.AccumulateFunction

Throws:

Exception

getResult

public Object getResult(Serializable context)
                 throws Exception

Specified by:

getResult in interface org.drools.runtime.rule.AccumulateFunction

Throws:

Exception

supportsReverse

public boolean supportsReverse()

Specified by:

supportsReverse in interface org.drools.runtime.rule.AccumulateFunction

getResultType

public Class<?> getResultType()

Specified by:

getResultType in interface org.drools.runtime.rule.TypedAccumulateFunction