org.apache.lucene.analysis.util.TokenizerFactory Maven / Gradle / Ivy
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* 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 org.apache.lucene.analysis.TokenStream;
import org.apache.lucene.analysis.Tokenizer;
import org.apache.lucene.util.AttributeFactory;
import java.util.Map;
import java.util.Set;
/**
* Abstract parent class for analysis factories that create {@link Tokenizer}
* instances.
*
* @since 3.1
*/
public abstract class TokenizerFactory extends AbstractAnalysisFactory {
private static final AnalysisSPILoader loader =
new AnalysisSPILoader<>(TokenizerFactory.class);
/** looks up a tokenizer by name from context classpath */
public static TokenizerFactory forName(String name, Map args) {
return loader.newInstance(name, args);
}
/** looks up a tokenizer class by name from context classpath */
public static Class lookupClass(String name) {
return loader.lookupClass(name);
}
/** returns a list of all available tokenizer names from context classpath */
public static Set availableTokenizers() {
return loader.availableServices();
}
/** looks up a SPI name for the specified tokenizer factory */
public static String findSPIName(Class 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 #availableTokenizers()},...) stay consistent.
*
* NOTE: Only new factories are added, existing ones are
* never removed or replaced.
*
*
This method is expensive and should only be called for discovery
* of new factories on the given classpath/classloader!
*/
public static void reloadTokenizers(ClassLoader classloader) {
loader.reload(classloader);
}
/**
* Initialize this factory via a set of key-value pairs.
*/
protected TokenizerFactory(Map args) {
super(args);
}
/** Creates a TokenStream of the specified input using the default attribute factory. */
public final Tokenizer create() {
return create(TokenStream.DEFAULT_TOKEN_ATTRIBUTE_FACTORY);
}
/** Creates a TokenStream of the specified input using the given AttributeFactory */
abstract public Tokenizer create(AttributeFactory factory);
}