/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You 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.servlet.jsp.el;

/**
 * <p>
 * This class is used to customize the way an ExpressionEvaluator resolves
 * variable references at evaluation time. For example, instances of this class
 * can implement their own variable lookup mechanisms, or introduce the notion
 * of "implicit variables" which override any other variables. An instance of
 * this class should be passed when evaluating an expression.
 * </p>
 * <p>
 * An instance of this class includes the context against which resolution will
 * happen
 * </p>
 *
 * @since JSP 2.0
 * @deprecated As of JSP 2.1, replaced by javax.el.ELResolver
 */
@SuppressWarnings("dep-ann")
// TCK signature test fails with annotation
public interface VariableResolver {

    /**
     * Resolves the specified variable. Returns null if the variable is not
     * found.
     *
     * @param pName
     *            the name of the variable to resolve
     * @return the result of the variable resolution
     * @throws ELException
     *             if a failure occurred while trying to resolve the given
     *             variable
     */
    Object resolveVariable(String pName) throws ELException;
}
