org.apache.el.lang.VariableMapperFactory Maven / Gradle / Ivy
/*
* Copyright 2006 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.el.lang;
import javax.el.ValueExpression;
import javax.el.VariableMapper;
public class VariableMapperFactory extends VariableMapper {
private final VariableMapper target;
private VariableMapper momento;
public VariableMapperFactory(VariableMapper target) {
if (target == null) {
throw new NullPointerException("Target VariableMapper cannot be null");
}
this.target = target;
}
public VariableMapper create() {
return this.momento;
}
public ValueExpression resolveVariable(String variable) {
ValueExpression expr = this.target.resolveVariable(variable);
if (expr != null) {
if (this.momento == null) {
this.momento = new VariableMapperImpl();
}
this.momento.setVariable(variable, expr);
}
return expr;
}
public ValueExpression setVariable(String variable, ValueExpression expression) {
throw new UnsupportedOperationException("Cannot Set Variables on Factory");
}
}