001// *************************************************************************************************************************** 002// * Licensed to the Apache Software Foundation (ASF) under one or more contributor license agreements. See the NOTICE file * 003// * distributed with this work for additional information regarding copyright ownership. The ASF licenses this file * 004// * to you under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance * 005// * with the License. You may obtain a copy of the License at * 006// * * 007// * http://www.apache.org/licenses/LICENSE-2.0 * 008// * * 009// * Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an * 010// * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the * 011// * specific language governing permissions and limitations under the License. * 012// *************************************************************************************************************************** 013package org.apache.juneau.utils; 014 015 016import java.io.*; 017import java.util.*; 018 019/** 020 * Interface for finding classpath resources. 021 * 022 * <p> 023 * Essentially a wrapper around {@link Class#getResourceAsStream(String)}, but with support for looking up resources 024 * with localized names (e.g. <js>"myfile_ja_JP.txt"</js>). 025 * 026 * <p> 027 * The following predefined implementations are provided: 028 * <ul> 029 * <li>{@link ClasspathResourceFinderSimple} - Simple searching of classpath. 030 * <li>{@link ClasspathResourceFinderBasic} - Same as above, but looks in local JVM working directory if resource 031 * can't be found on classpath. 032 * <li>{@link ClasspathResourceFinderRecursive} - Same as above, except if the resource can't be found on the 033 * classpath relative to the base class, recursively searches up the parent class hierarchy. 034 * </ul> 035 */ 036public interface ClasspathResourceFinder { 037 038 /** 039 * Represents "no" classpath resource finder. 040 */ 041 public static final class Null implements ClasspathResourceFinder { 042 @Override 043 public InputStream findResource(Class<?> baseClass, String name, Locale locale) throws IOException { 044 throw new NoSuchMethodError(); 045 } 046 } 047 048 /** 049 * Returns the contents of the resource with the specified name. 050 * 051 * @param baseClass 052 * The class to use to retrieve the resource. 053 * @param name The resource name. 054 * See {@link Class#getResource(String)} for format. 055 * @param locale 056 * The locale of the resource to retrieve. 057 * <br>If <jk>null</jk>, won't look for localized file names. 058 * @return The resolved resource contents, or <jk>null</jk> if the resource was not found. 059 * @throws IOException 060 */ 061 InputStream findResource(Class<?> baseClass, String name, Locale locale) throws IOException; 062}