| /* |
| * 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.FileNotFoundException; |
| import java.io.IOException; |
| import java.io.InputStream; |
| import java.nio.file.Files; |
| import java.nio.file.NoSuchFileException; |
| import java.nio.file.Path; |
| |
| /** |
| * Simple {@link ResourceLoader} that opens resource files |
| * from the local file system, optionally resolving against |
| * a base directory. |
| * |
| * <p>This loader wraps a delegate {@link ResourceLoader} |
| * that is used to resolve all files, the current base directory |
| * does not contain. {@link #newInstance} is always resolved |
| * against the delegate, as a {@link ClassLoader} is needed. |
| * |
| * <p>You can chain several {@code FilesystemResourceLoader}s |
| * to allow lookup of files in more than one base directory. |
| */ |
| public final class FilesystemResourceLoader implements ResourceLoader { |
| private final Path baseDirectory; |
| private final ResourceLoader delegate; |
| |
| /** |
| * Creates a resource loader that resolves resources against the given |
| * base directory (may be {@code null} to refer to CWD). |
| * Files not found in file system and class lookups are delegated to context |
| * classloader. |
| * |
| * @deprecated You should not use this ctor, because it uses the thread's context |
| * class loader as fallback for resource lookups, which is bad programming style. |
| * Please specify a {@link ClassLoader} instead. |
| * @see #FilesystemResourceLoader(Path, ClassLoader) |
| */ |
| @Deprecated |
| public FilesystemResourceLoader(Path baseDirectory) { |
| this(baseDirectory, new ClasspathResourceLoader()); |
| } |
| |
| /** |
| * Creates a resource loader that resolves resources against the given |
| * base directory (may be {@code null} to refer to CWD). |
| * Files not found in file system and class lookups are delegated to context |
| * classloader. |
| */ |
| public FilesystemResourceLoader(Path baseDirectory, ClassLoader delegate) { |
| this(baseDirectory, new ClasspathResourceLoader(delegate)); |
| } |
| |
| /** |
| * Creates a resource loader that resolves resources against the given |
| * base directory (may be {@code null} to refer to CWD). |
| * Files not found in file system and class lookups are delegated |
| * to the given delegate {@link ResourceLoader}. |
| */ |
| public FilesystemResourceLoader(Path baseDirectory, ResourceLoader delegate) { |
| if (baseDirectory == null) { |
| throw new NullPointerException(); |
| } |
| if (!Files.isDirectory(baseDirectory)) |
| throw new IllegalArgumentException(baseDirectory + " is not a directory"); |
| if (delegate == null) |
| throw new IllegalArgumentException("delegate ResourceLoader may not be null"); |
| this.baseDirectory = baseDirectory; |
| this.delegate = delegate; |
| } |
| |
| @Override |
| public InputStream openResource(String resource) throws IOException { |
| try { |
| return Files.newInputStream(baseDirectory.resolve(resource)); |
| } catch (FileNotFoundException | NoSuchFileException fnfe) { |
| return delegate.openResource(resource); |
| } |
| } |
| |
| @Override |
| public <T> T newInstance(String cname, Class<T> expectedType) { |
| return delegate.newInstance(cname, expectedType); |
| } |
| |
| @Override |
| public <T> Class<? extends T> findClass(String cname, Class<T> expectedType) { |
| return delegate.findClass(cname, expectedType); |
| } |
| } |