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Lucene example source code file (WildcardQuery.java)
The Lucene WildcardQuery.java source codepackage org.apache.lucene.search; /** * 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 org.apache.lucene.index.IndexReader; import org.apache.lucene.index.Term; import org.apache.lucene.util.ToStringUtils; import java.io.IOException; /** Implements the wildcard search query. Supported wildcards are <code>*, which * matches any character sequence (including the empty one), and <code>?, * which matches any single character. Note this query can be slow, as it * needs to iterate over many terms. In order to prevent extremely slow WildcardQueries, * a Wildcard term should not start with one of the wildcards <code>* or * <code>?. * * <p>This query uses the {@link * MultiTermQuery#CONSTANT_SCORE_AUTO_REWRITE_DEFAULT} * rewrite method. * * @see WildcardTermEnum */ public class WildcardQuery extends MultiTermQuery { private boolean termContainsWildcard; private boolean termIsPrefix; protected Term term; public WildcardQuery(Term term) { this.term = term; String text = term.text(); this.termContainsWildcard = (text.indexOf('*') != -1) || (text.indexOf('?') != -1); this.termIsPrefix = termContainsWildcard && (text.indexOf('?') == -1) && (text.indexOf('*') == text.length() - 1); } @Override protected FilteredTermEnum getEnum(IndexReader reader) throws IOException { if (termIsPrefix) { return new PrefixTermEnum(reader, term.createTerm(term.text() .substring(0, term.text().indexOf('*')))); } else if (termContainsWildcard) { return new WildcardTermEnum(reader, getTerm()); } else { return new SingleTermEnum(reader, getTerm()); } } /** * Returns the pattern term. */ public Term getTerm() { return term; } /** Prints a user-readable version of this query. */ @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(ToStringUtils.boost(getBoost())); return buffer.toString(); } @Override public int hashCode() { final int prime = 31; int result = super.hashCode(); result = prime * result + ((term == null) ? 0 : term.hashCode()); return result; } @Override public boolean equals(Object obj) { if (this == obj) return true; if (!super.equals(obj)) return false; if (getClass() != obj.getClass()) return false; WildcardQuery other = (WildcardQuery) obj; if (term == null) { if (other.term != null) return false; } else if (!term.equals(other.term)) return false; return true; } } Other Lucene examples (source code examples)Here is a short list of links related to this Lucene WildcardQuery.java source code file: |
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