/* * 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 org.apache.lucene.analysis.util; import java.io.IOException; import java.io.InputStream; /** * Simple {@link ResourceLoader} that uses {@link ClassLoader#getResourceAsStream(String)} * and {@link Class#forName(String,boolean,ClassLoader)} to open resources and * classes, respectively. */ public final class ClasspathResourceLoader implements ResourceLoader { private final Class<?> clazz; private final ClassLoader loader; /** * Creates an instance using the context classloader to load Resources and classes. * Resource paths must be absolute. */ public ClasspathResourceLoader() { this(Thread.currentThread().getContextClassLoader()); } /** * Creates an instance using the given classloader to load Resources and classes. * Resource paths must be absolute. */ public ClasspathResourceLoader(ClassLoader loader) { this(null, loader); } /** * Creates an instance using the context classloader to load Resources and classes * Resources are resolved relative to the given class, if path is not absolute. */ public ClasspathResourceLoader(Class<?> clazz) { this(clazz, clazz.getClassLoader()); } private ClasspathResourceLoader(Class<?> clazz, ClassLoader loader) { this.clazz = clazz; this.loader = loader; } @Override public InputStream openResource(String resource) throws IOException { final InputStream stream = (clazz != null) ? clazz.getResourceAsStream(resource) : loader.getResourceAsStream(resource); if (stream == null) throw new IOException("Resource not found: " + resource); return stream; } @Override public <T> Class<? extends T> findClass(String cname, Class<T> expectedType) { try { return Class.forName(cname, true, loader).asSubclass(expectedType); } catch (Exception e) { throw new RuntimeException("Cannot load class: " + cname, e); } } @Override public <T> T newInstance(String cname, Class<T> expectedType) { Class<? extends T> clazz = findClass(cname, expectedType); try { return clazz.newInstance(); } catch (Exception e) { throw new RuntimeException("Cannot create instance: " + cname, e); } } }