001 /* 002 * Copyright 2006-2007 Stephen J. McConnell. 003 * 004 * Licensed under the Apache License, Version 2.0 (the "License"); 005 * you may not use this file except in compliance with the License. 006 * You may obtain a copy of the License at 007 * 008 * http://www.apache.org/licenses/LICENSE-2.0 009 * 010 * Unless required by applicable law or agreed to in writing, software 011 * distributed under the License is distributed on an "AS IS" BASIS, 012 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or 013 * implied. 014 * 015 * See the License for the specific language governing permissions and 016 * limitations under the License. 017 */ 018 019 package net.dpml.util; 020 021 /** 022 * Interace implemented by a value (key, ref, and property) resolver. 023 * 024 * @author <a href="http://www.dpml.net">Digital Product Management Library</a> 025 * @version 2.1.1 026 */ 027 public interface Resolver 028 { 029 /** 030 * Return a property value. 031 * @param key the property key 032 * @return the property value 033 */ 034 String getProperty( String key ); 035 036 /** 037 * Return a property value. 038 * @param key the property key 039 * @param value the default value 040 * @return the property value 041 */ 042 String getProperty( String key, String value ); 043 044 /** 045 * Symbolic expansion of a supplied value. 046 * Replace any occurances of ${[key]} with the value of the property 047 * assigned to the [key] in system properties. 048 * @param value a string containing possibly multiple ${[value]} sequences 049 * @return the expanded string 050 */ 051 String resolve( String value ); 052 }