001 /* 002 * Licensed to the Apache Software Foundation (ASF) under one or more 003 * contributor license agreements. See the NOTICE file distributed with 004 * this work for additional information regarding copyright ownership. 005 * The ASF licenses this file to You under the Apache License, Version 2.0 006 * (the "License"); you may not use this file except in compliance with 007 * the License. You may obtain a copy of the License at 008 * 009 * http://www.apache.org/licenses/LICENSE-2.0 010 * 011 * Unless required by applicable law or agreed to in writing, software 012 * distributed under the License is distributed on an "AS IS" BASIS, 013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 014 * See the License for the specific language governing permissions and 015 * limitations under the License. 016 */ 017 018 package javax.servlet.jsp.el; 019 020 /** 021 * <p>This class is used to customize the way an ExpressionEvaluator resolves 022 * variable references at evaluation time. For example, instances of this class can 023 * implement their own variable lookup mechanisms, or introduce the 024 * notion of "implicit variables" which override any other variables. 025 * An instance of this class should be passed when evaluating 026 * an expression.</p> 027 * 028 * <p>An instance of this class includes the context against which resolution 029 * will happen</p> 030 * 031 * @since 2.0 032 * @deprecated 033 */ 034 public interface VariableResolver 035 { 036 //------------------------------------- 037 /** 038 * Resolves the specified variable. 039 * Returns null if the variable is not found. 040 * 041 * @param pName the name of the variable to resolve 042 * @return the result of the variable resolution 043 * 044 * @throws ELException if a failure occurred while trying to resolve 045 * the given variable 046 **/ 047 public Object resolveVariable (String pName) 048 throws ELException; 049 050 //------------------------------------- 051 }