| /* |
| * 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.search.suggest.document; |
| |
| import java.io.IOException; |
| |
| import org.apache.lucene.index.IndexReader; |
| import org.apache.lucene.index.LeafReader; |
| import org.apache.lucene.index.LeafReaderContext; |
| import org.apache.lucene.index.Term; |
| import org.apache.lucene.index.Terms; |
| import org.apache.lucene.search.Query; |
| import org.apache.lucene.search.suggest.BitsProducer; |
| |
| import static org.apache.lucene.search.suggest.document.CompletionAnalyzer.HOLE_CHARACTER; |
| import static org.apache.lucene.analysis.miscellaneous.ConcatenateGraphFilter.SEP_LABEL; |
| |
| /** |
| * Abstract {@link Query} that match documents containing terms with a specified prefix |
| * filtered by {@link BitsProducer}. This should be used to query against any {@link SuggestField}s |
| * or {@link ContextSuggestField}s of documents. |
| * <p> |
| * Use {@link SuggestIndexSearcher#suggest(CompletionQuery, int, boolean)} to execute any query |
| * that provides a concrete implementation of this query. Example below shows using this query |
| * to retrieve the top 5 documents. |
| * |
| * <pre class="prettyprint"> |
| * SuggestIndexSearcher searcher = new SuggestIndexSearcher(reader); |
| * TopSuggestDocs suggestDocs = searcher.suggest(query, 5); |
| * </pre> |
| * This query rewrites to an appropriate {@link CompletionQuery} depending on the |
| * type ({@link SuggestField} or {@link ContextSuggestField}) of the field the query is run against. |
| * |
| * @lucene.experimental |
| */ |
| public abstract class CompletionQuery extends Query { |
| |
| /** |
| * Term to query against |
| */ |
| private final Term term; |
| |
| /** |
| * {@link BitsProducer} which is used to filter the document scope. |
| */ |
| private final BitsProducer filter; |
| |
| /** |
| * Creates a base Completion query against a <code>term</code> |
| * with a <code>filter</code> to scope the documents |
| */ |
| protected CompletionQuery(Term term, BitsProducer filter) { |
| validate(term.text()); |
| this.term = term; |
| this.filter = filter; |
| } |
| |
| /** |
| * Returns a {@link BitsProducer}. Only suggestions matching the returned |
| * bits will be returned. |
| */ |
| public BitsProducer getFilter() { |
| return filter; |
| } |
| |
| /** |
| * Returns the field name this query should |
| * be run against |
| */ |
| public String getField() { |
| return term.field(); |
| } |
| |
| /** |
| * Returns the term to be queried against |
| */ |
| public Term getTerm() { |
| return term; |
| } |
| |
| @Override |
| public Query rewrite(IndexReader reader) throws IOException { |
| byte type = 0; |
| boolean first = true; |
| Terms terms; |
| for (LeafReaderContext context : reader.leaves()) { |
| LeafReader leafReader = context.reader(); |
| try { |
| if ((terms = leafReader.terms(getField())) == null) { |
| continue; |
| } |
| } catch (IOException e) { |
| continue; |
| } |
| if (terms instanceof CompletionTerms) { |
| CompletionTerms completionTerms = (CompletionTerms) terms; |
| byte t = completionTerms.getType(); |
| if (first) { |
| type = t; |
| first = false; |
| } else if (type != t) { |
| throw new IllegalStateException(getField() + " has values of multiple types"); |
| } |
| } |
| } |
| |
| if (first == false) { |
| if (this instanceof ContextQuery) { |
| if (type == SuggestField.TYPE) { |
| throw new IllegalStateException(this.getClass().getSimpleName() |
| + " can not be executed against a non context-enabled SuggestField: " |
| + getField()); |
| } |
| } else { |
| if (type == ContextSuggestField.TYPE) { |
| return new ContextQuery(this); |
| } |
| } |
| } |
| return super.rewrite(reader); |
| } |
| |
| @Override |
| public String toString(String field) { |
| StringBuilder buffer = new StringBuilder(); |
| if (!term.field().equals(field)) { |
| buffer.append(term.field()); |
| buffer.append(":"); |
| } |
| buffer.append(term.text()); |
| buffer.append('*'); |
| if (filter != null) { |
| buffer.append(","); |
| buffer.append("filter"); |
| buffer.append(":"); |
| buffer.append(filter.toString()); |
| } |
| return buffer.toString(); |
| } |
| |
| private void validate(String termText) { |
| for (int i = 0; i < termText.length(); i++) { |
| switch (termText.charAt(i)) { |
| case HOLE_CHARACTER: |
| throw new IllegalArgumentException( |
| "Term text cannot contain HOLE character U+001E; this character is reserved"); |
| case SEP_LABEL: |
| throw new IllegalArgumentException( |
| "Term text cannot contain unit separator character U+001F; this character is reserved"); |
| default: |
| break; |
| } |
| } |
| } |
| } |