org.apache.jasper.runtime.VariableMapperImpl 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.jasper.runtime;
import java.util.HashMap;
import javax.el.ELContext;
import javax.el.ELResolver;
import javax.el.VariableMapper;
import javax.el.ValueExpression;
/**
* This is the implementation of VariableMapper.
* The compiler creates an empty variable mapper when an ELContext is created.
* The variable mapper will be updated by tag handlers, if necessary.
*
* @author Kin-man Chung
* @version $Change: 181177 $$DateTime: 2001/06/26 08:45:09 $$Author: kchung $
*/
public class VariableMapperImpl extends VariableMapper
{
//-------------------------------------
/**
* Constructor
*/
public VariableMapperImpl () {
map = new HashMap();
}
//-------------------------------------
/**
* Resolves the specified variable within the given context.
* Returns null if the variable is not found.
*/
public ValueExpression resolveVariable (String variable) {
return map.get(variable);
}
public ValueExpression setVariable(String variable,
ValueExpression expression) {
ValueExpression prev = null;
if (expression == null) {
map.remove(variable);
} else {
prev = map.get(variable);
map.put(variable, expression);
}
return prev;
}
private HashMap map;
}