javax.el.VariableMapper 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 javax.el;
/**
* The interface to a map between EL variables and the EL expressions
* they are associated with.
*
* @since JSP 2.1
*/
public abstract class VariableMapper {
/**
* @param variable The variable name
* @return the ValueExpression assigned to the variable,
* null if there is no previous assignment to this variable.
*/
public abstract ValueExpression resolveVariable(
String variable);
/**
* Assign a ValueExpression to an EL variable, replacing
* any previously assignment to the same variable.
* The assignment for the variable is removed if
* the expression is null
.
*
* @param variable The variable name
* @param expression The ValueExpression to be assigned
* to the variable.
* @return The previous ValueExpression assigned to this variable,
* null if there is no previous assignment to this variable.
*/
public abstract ValueExpression setVariable(
String variable,
ValueExpression expression);
}