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Lucene example source code file (ReaderUtil.java)
The Lucene ReaderUtil.java source codepackage org.apache.lucene.util; /** * 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. */ import java.io.IOException; import java.util.ArrayList; import java.util.List; import org.apache.lucene.index.IndexReader; /** * Common util methods for dealing with {@link IndexReader}s. * * @lucene.internal */ public final class ReaderUtil { private ReaderUtil() {} // no instance /** * Gathers sub-readers from reader into a List. * * @param allSubReaders * @param reader */ public static void gatherSubReaders(List<IndexReader> allSubReaders, IndexReader reader) { IndexReader[] subReaders = reader.getSequentialSubReaders(); if (subReaders == null) { // Add the reader itself, and do not recurse allSubReaders.add(reader); } else { for (int i = 0; i < subReaders.length; i++) { gatherSubReaders(allSubReaders, subReaders[i]); } } } /** Recursively visits all sub-readers of a reader. You * should subclass this and override the add method to * gather what you need. * * @lucene.experimental */ public static abstract class Gather { private final IndexReader topReader; public Gather(IndexReader r) { topReader = r; } public int run() throws IOException { return run(0, topReader); } public int run(int docBase) throws IOException { return run(docBase, topReader); } private int run(int base, IndexReader reader) throws IOException { IndexReader[] subReaders = reader.getSequentialSubReaders(); if (subReaders == null) { // atomic reader add(base, reader); base += reader.maxDoc(); } else { // composite reader for (int i = 0; i < subReaders.length; i++) { base = run(base, subReaders[i]); } } return base; } protected abstract void add(int base, IndexReader r) throws IOException; } /** * Returns sub IndexReader that contains the given document id. * * @param doc id of document * @param reader parent reader * @return sub reader of parent which contains the specified doc id */ public static IndexReader subReader(int doc, IndexReader reader) { List<IndexReader> subReadersList = new ArrayList Other Lucene examples (source code examples)Here is a short list of links related to this Lucene ReaderUtil.java source code file: |
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