binaryoperator.java

jBpm是一个灵活可扩展的工作流管理系统。作为jBpm运行时server输入的业务流程使用简单强大的语言表达并打包在流程档案中

/*
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package org.jbpm.jpdl.el.impl;

import org.jbpm.jpdl.el.ELException;

/**
 *
 * <p>This is the superclass for all binary operators
 * 
 * @author Nathan Abramson - Art Technology Group
 * @version $Change: 181177 $$DateTime: 2001/06/26 08:45:09 $$Author: tombaeyens $
 **/

public abstract class BinaryOperator
{
  //-------------------------------------
  /**
   *
   * Constructor
   **/
  public BinaryOperator ()
  {
  }

  //-------------------------------------
  // Expression methods
  //-------------------------------------
  /**
   *
   * Returns the symbol representing the operator
   **/
  public abstract String getOperatorSymbol ();

  //-------------------------------------
  /**
   *
   * Applies the operator to the given pair of values
   **/
  public abstract Object apply (Object pLeft,
				Object pRight,
				Logger pLogger)
    throws ELException;

  //-------------------------------------
  /**
   *
   * Returns true if evaluation is necessary given the specified Left
   * value.  The And/OrOperators make use of this
   **/
  public boolean shouldEvaluate (Object pLeft)
  {
    return true;
  }

  //-------------------------------------
  /**
   *
   * Returns true if the operator expects its arguments to be coerced
   * to Booleans.  The And/Or operators set this to true.
   **/
  public boolean shouldCoerceToBoolean ()
  {
    return false;
  }

  //-------------------------------------
}