org.drools.runtime.rule.AccumulateFunction Maven / Gradle / Ivy
package org.drools.runtime.rule;
import java.io.Serializable;
/**
* An interface for accumulate external function implementations
*/
public interface AccumulateFunction {
/**
* Creates and returns a new context object
* @return
*/
public Serializable createContext();
/**
* Initializes the accumulator
* @param context
* @throws Exception
*/
public void init(Serializable context) throws Exception;
/**
* Executes the accumulation action
* @param context
* @param value
*/
public void accumulate(Serializable context,
Object value);
/**
* Reverses the accumulation action
* @param context
* @param value
* @throws Exception
*/
public void reverse(Serializable context,
Object value) throws Exception;
/**
* Returns the current value in this accumulation session
*
* @param context
* @return
* @throws Exception
*/
public Object getResult(Serializable context) throws Exception;
/**
* True if the function supports reverse. False otherwise.
*
* @return
*/
public boolean supportsReverse();
}