| /* |
| * 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.Reader; |
| import java.util.Map; |
| import java.util.Set; |
| |
| import org.apache.lucene.analysis.CharFilter; |
| |
| /** |
| * Abstract parent class for analysis factories that create {@link CharFilter} |
| * instances. |
| * |
| * @since 3.1 |
| */ |
| public abstract class CharFilterFactory extends AbstractAnalysisFactory { |
| |
| private static final AnalysisSPILoader<CharFilterFactory> loader = |
| new AnalysisSPILoader<>(CharFilterFactory.class); |
| |
| /** looks up a charfilter by name from context classpath */ |
| public static CharFilterFactory forName(String name, Map<String,String> args) { |
| return loader.newInstance(name, args); |
| } |
| |
| /** looks up a charfilter class by name from context classpath */ |
| public static Class<? extends CharFilterFactory> lookupClass(String name) { |
| return loader.lookupClass(name); |
| } |
| |
| /** returns a list of all available charfilter names */ |
| public static Set<String> availableCharFilters() { |
| return loader.availableServices(); |
| } |
| |
| /** looks up a SPI name for the specified char filter factory */ |
| public static String findSPIName(Class<? extends CharFilterFactory> serviceClass) { |
| try { |
| return lookupSPIName(serviceClass); |
| } catch (NoSuchFieldException | IllegalAccessException | IllegalStateException e) { |
| throw new IllegalStateException(e); |
| } |
| } |
| |
| /** |
| * Reloads the factory list from the given {@link ClassLoader}. |
| * Changes to the factories are visible after the method ends, all |
| * iterators ({@link #availableCharFilters()},...) stay consistent. |
| * |
| * <p><b>NOTE:</b> Only new factories are added, existing ones are |
| * never removed or replaced. |
| * |
| * <p><em>This method is expensive and should only be called for discovery |
| * of new factories on the given classpath/classloader!</em> |
| */ |
| public static void reloadCharFilters(ClassLoader classloader) { |
| loader.reload(classloader); |
| } |
| |
| /** |
| * Initialize this factory via a set of key-value pairs. |
| */ |
| protected CharFilterFactory(Map<String,String> args) { |
| super(args); |
| } |
| |
| /** Wraps the given Reader with a CharFilter. */ |
| public abstract Reader create(Reader input); |
| |
| /** |
| * Normalize the specified input Reader |
| * While the default implementation returns input unchanged, |
| * char filters that should be applied at normalization time can delegate to {@code create} method. |
| */ |
| public Reader normalize(Reader input) { |
| return input; |
| } |
| } |