org.apache.taglibs.standard.lang.jstl.BinaryOperatorExpression Maven / Gradle / Ivy
/*
* Copyright (c) 1997-2018 Oracle and/or its affiliates. All rights reserved.
* Copyright 2004 The Apache Software Foundation
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.apache.taglibs.standard.lang.jstl;
import java.util.List;
import java.util.Map;
/**
*
* An expression representing a binary operator on a value
*
* @author Nathan Abramson - Art Technology Group
* @author Shawn Bayern
* @version $Change: 181177 $$DateTime: 2001/06/26 08:45:09 $$Author: kchung $
**/
public class BinaryOperatorExpression
extends Expression
{
//-------------------------------------
// Properties
//-------------------------------------
// property expression
Expression mExpression;
public Expression getExpression ()
{ return mExpression; }
public void setExpression (Expression pExpression)
{ mExpression = pExpression; }
//-------------------------------------
// property operators
List mOperators;
public List getOperators ()
{ return mOperators; }
public void setOperators (List pOperators)
{ mOperators = pOperators; }
//-------------------------------------
// property expressions
List mExpressions;
public List getExpressions ()
{ return mExpressions; }
public void setExpressions (List pExpressions)
{ mExpressions = pExpressions; }
//-------------------------------------
/**
*
* Constructor
**/
public BinaryOperatorExpression (Expression pExpression,
List pOperators,
List pExpressions)
{
mExpression = pExpression;
mOperators = pOperators;
mExpressions = pExpressions;
}
//-------------------------------------
// Expression methods
//-------------------------------------
/**
*
* Returns the expression in the expression language syntax
**/
public String getExpressionString ()
{
StringBuffer buf = new StringBuffer ();
buf.append ("(");
buf.append (mExpression.getExpressionString ());
for (int i = 0; i < mOperators.size (); i++) {
BinaryOperator operator = (BinaryOperator) mOperators.get (i);
Expression expression = (Expression) mExpressions.get (i);
buf.append (" ");
buf.append (operator.getOperatorSymbol ());
buf.append (" ");
buf.append (expression.getExpressionString ());
}
buf.append (")");
return buf.toString ();
}
//-------------------------------------
/**
*
* Evaluates to the literal value
**/
public Object evaluate (Object pContext,
VariableResolver pResolver,
Map functions,
String defaultPrefix,
Logger pLogger)
throws ELException
{
Object value = mExpression.evaluate (pContext, pResolver, functions,
defaultPrefix, pLogger);
for (int i = 0; i < mOperators.size (); i++) {
BinaryOperator operator = (BinaryOperator) mOperators.get (i);
// For the And/Or operators, we need to coerce to a boolean
// before testing if we shouldEvaluate
if (operator.shouldCoerceToBoolean ()) {
value = Coercions.coerceToBoolean (value, pLogger);
}
if (operator.shouldEvaluate (value)) {
Expression expression = (Expression) mExpressions.get (i);
Object nextValue = expression.evaluate (pContext, pResolver,
functions, defaultPrefix,
pLogger);
value = operator.apply (value, nextValue, pContext, pLogger);
}
}
return value;
}
//-------------------------------------
}