001 /* $Id: VariableExpander.java 471661 2006-11-06 08:09:25Z skitching $ 002 * 003 * Licensed to the Apache Software Foundation (ASF) under one or more 004 * contributor license agreements. See the NOTICE file distributed with 005 * this work for additional information regarding copyright ownership. 006 * The ASF licenses this file to You under the Apache License, Version 2.0 007 * (the "License"); you may not use this file except in compliance with 008 * the License. You may obtain a copy of the License at 009 * 010 * http://www.apache.org/licenses/LICENSE-2.0 011 * 012 * Unless required by applicable law or agreed to in writing, software 013 * distributed under the License is distributed on an "AS IS" BASIS, 014 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 015 * See the License for the specific language governing permissions and 016 * limitations under the License. 017 */ 018 019 020 package org.apache.commons.digester.substitution; 021 022 /** 023 * <p>An Interface describing a class capable of expanding strings which 024 * may contain variable references. The exact syntax of the "reference", 025 * and the mechanism for determining the corresponding value to be used 026 * is up to the concrete implementation.</p> 027 * 028 * @since 1.6 029 */ 030 public interface VariableExpander { 031 /** 032 * Return the input string with any variables replaced by their 033 * corresponding value. If there are no variables in the string, 034 * then the input parameter is returned unaltered. 035 */ 036 public String expand(String param); 037 } 038