Java tutorial
/* * ModeShape (http://www.modeshape.org) * See the COPYRIGHT.txt file distributed with this work for information * regarding copyright ownership. Some portions may be licensed * to Red Hat, Inc. under one or more contributor license agreements. * See the AUTHORS.txt file in the distribution for a full listing of * individual contributors. * * ModeShape is free software. Unless otherwise indicated, all code in ModeShape * is licensed to you under the terms of the GNU Lesser General Public License as * published by the Free Software Foundation; either version 2.1 of * the License, or (at your option) any later version. * * ModeShape is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * Lesser General Public License for more details. * * You should have received a copy of the GNU Lesser General Public * License along with this software; if not, write to the Free * Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA * 02110-1301 USA, or see the FSF site: http://www.fsf.org. */ package org.modeshape.search.lucene.query; import java.io.IOException; import org.apache.lucene.document.Document; import org.apache.lucene.document.FieldSelector; import org.apache.lucene.document.FieldSelectorResult; import org.apache.lucene.index.IndexReader; import org.apache.lucene.search.Query; import org.apache.lucene.search.Weight; import org.modeshape.graph.property.Path; import org.modeshape.graph.property.PathFactory; import org.modeshape.graph.property.ValueComparators; import org.modeshape.graph.property.ValueFactories; import org.modeshape.graph.property.ValueFactory; import org.modeshape.graph.query.model.Comparison; /** * A Lucene {@link Query} implementation that is used to apply a {@link Comparison} constraint against the name of nodes. This * query implementation works by using the weight and {@link Weight#scorer(IndexReader, boolean, boolean) scorer} of the wrapped * query to score (and return) only those documents that correspond to nodes with Names that satisfy the constraint. */ public class CompareNameQuery extends CompareQuery<Path.Segment> { private static final long serialVersionUID = 1L; protected static final Evaluator<Path.Segment> IS_LESS_THAN = new Evaluator<Path.Segment>() { private static final long serialVersionUID = 1L; @Override public boolean satisfiesConstraint(Path.Segment nodeValue, Path.Segment constraintValue) { return ValueComparators.PATH_SEGMENT_COMPARATOR.compare(nodeValue, constraintValue) < 0; } @Override public String toString() { return " < "; } }; protected static final Evaluator<Path.Segment> IS_LESS_THAN_OR_EQUAL_TO = new Evaluator<Path.Segment>() { private static final long serialVersionUID = 1L; @Override public boolean satisfiesConstraint(Path.Segment nodeValue, Path.Segment constraintValue) { return ValueComparators.PATH_SEGMENT_COMPARATOR.compare(nodeValue, constraintValue) <= 0; } @Override public String toString() { return " <= "; } }; protected static final Evaluator<Path.Segment> IS_GREATER_THAN = new Evaluator<Path.Segment>() { private static final long serialVersionUID = 1L; @Override public boolean satisfiesConstraint(Path.Segment nodeValue, Path.Segment constraintValue) { return ValueComparators.PATH_SEGMENT_COMPARATOR.compare(nodeValue, constraintValue) > 0; } @Override public String toString() { return " > "; } }; protected static final Evaluator<Path.Segment> IS_GREATER_THAN_OR_EQUAL_TO = new Evaluator<Path.Segment>() { private static final long serialVersionUID = 1L; @Override public boolean satisfiesConstraint(Path.Segment nodeValue, Path.Segment constraintValue) { return ValueComparators.PATH_SEGMENT_COMPARATOR.compare(nodeValue, constraintValue) >= 0; } @Override public String toString() { return " >= "; } }; protected static final Evaluator<Path.Segment> IS_LESS_THAN_NO_SNS = new Evaluator<Path.Segment>() { private static final long serialVersionUID = 1L; @Override public boolean satisfiesConstraint(Path.Segment nodeValue, Path.Segment constraintValue) { return ValueComparators.PATH_SEGMENT_NAME_COMPARATOR.compare(nodeValue, constraintValue) < 0; } @Override public String toString() { return " < "; } }; protected static final Evaluator<Path.Segment> IS_LESS_THAN_OR_EQUAL_TO_NO_SNS = new Evaluator<Path.Segment>() { private static final long serialVersionUID = 1L; @Override public boolean satisfiesConstraint(Path.Segment nodeValue, Path.Segment constraintValue) { return ValueComparators.PATH_SEGMENT_NAME_COMPARATOR.compare(nodeValue, constraintValue) <= 0; } @Override public String toString() { return " <= "; } }; protected static final Evaluator<Path.Segment> IS_GREATER_THAN_NO_SNS = new Evaluator<Path.Segment>() { private static final long serialVersionUID = 1L; @Override public boolean satisfiesConstraint(Path.Segment nodeValue, Path.Segment constraintValue) { return ValueComparators.PATH_SEGMENT_NAME_COMPARATOR.compare(nodeValue, constraintValue) > 0; } @Override public String toString() { return " > "; } }; protected static final Evaluator<Path.Segment> IS_GREATER_THAN_OR_EQUAL_TO_NO_SNS = new Evaluator<Path.Segment>() { private static final long serialVersionUID = 1L; @Override public boolean satisfiesConstraint(Path.Segment nodeValue, Path.Segment constraintValue) { return ValueComparators.PATH_SEGMENT_NAME_COMPARATOR.compare(nodeValue, constraintValue) >= 0; } @Override public String toString() { return " >= "; } }; /** * Construct a {@link Query} implementation that scores documents such that the node represented by the document has a name * that is greater than the supplied constraint name. * * @param constraintValue the constraint value; may not be null * @param localNameField the name of the document field containing the local name value; may not be null * @param snsIndexFieldName the name of the document field containing the same-name-sibling index; may not be null * @param factories the value factories that can be used during the scoring; may not be null * @param caseSensitive true if the comparison should be done in a case-sensitive manner, or false if it is to be * case-insensitive * @param includeSns true if the SNS index should be considered, or false if the SNS value should be ignored * @return the query; never null */ public static CompareNameQuery createQueryForNodesWithNameGreaterThan(Path.Segment constraintValue, String localNameField, String snsIndexFieldName, ValueFactories factories, boolean caseSensitive, boolean includeSns) { return new CompareNameQuery(localNameField, snsIndexFieldName, constraintValue, factories.getPathFactory(), factories.getStringFactory(), factories.getLongFactory(), includeSns ? IS_GREATER_THAN : IS_GREATER_THAN_NO_SNS, caseSensitive); } /** * Construct a {@link Query} implementation that scores documents such that the node represented by the document has a name * that is greater than or equal to the supplied constraint name. * * @param constraintValue the constraint value; may not be null * @param localNameField the name of the document field containing the local name value; may not be null * @param snsIndexFieldName the name of the document field containing the same-name-sibling index; may not be null * @param factories the value factories that can be used during the scoring; may not be null * @param caseSensitive true if the comparison should be done in a case-sensitive manner, or false if it is to be * case-insensitive * @param includeSns true if the SNS index should be considered, or false if the SNS value should be ignored * @return the query; never null */ public static CompareNameQuery createQueryForNodesWithNameGreaterThanOrEqualTo(Path.Segment constraintValue, String localNameField, String snsIndexFieldName, ValueFactories factories, boolean caseSensitive, boolean includeSns) { return new CompareNameQuery(localNameField, snsIndexFieldName, constraintValue, factories.getPathFactory(), factories.getStringFactory(), factories.getLongFactory(), includeSns ? IS_GREATER_THAN_OR_EQUAL_TO : IS_GREATER_THAN_OR_EQUAL_TO_NO_SNS, caseSensitive); } /** * Construct a {@link Query} implementation that scores documents such that the node represented by the document has a name * that is less than the supplied constraint name. * * @param constraintValue the constraint value; may not be null * @param localNameField the name of the document field containing the local name value; may not be null * @param snsIndexFieldName the name of the document field containing the same-name-sibling index; may not be null * @param factories the value factories that can be used during the scoring; may not be null * @param caseSensitive true if the comparison should be done in a case-sensitive manner, or false if it is to be * case-insensitive * @param includeSns true if the SNS index should be considered, or false if the SNS value should be ignored * @return the query; never null */ public static CompareNameQuery createQueryForNodesWithNameLessThan(Path.Segment constraintValue, String localNameField, String snsIndexFieldName, ValueFactories factories, boolean caseSensitive, boolean includeSns) { return new CompareNameQuery(localNameField, snsIndexFieldName, constraintValue, factories.getPathFactory(), factories.getStringFactory(), factories.getLongFactory(), includeSns ? IS_LESS_THAN : IS_LESS_THAN_NO_SNS, caseSensitive); } /** * Construct a {@link Query} implementation that scores documents such that the node represented by the document has a name * that is less than or equal to the supplied constraint name. * * @param constraintValue the constraint value; may not be null * @param localNameField the name of the document field containing the local name value; may not be null * @param snsIndexFieldName the name of the document field containing the same-name-sibling index; may not be null * @param factories the value factories that can be used during the scoring; may not be null * @param caseSensitive true if the comparison should be done in a case-sensitive manner, or false if it is to be * case-insensitive * @param includeSns true if the SNS index should be considered, or false if the SNS value should be ignored * @return the query; never null */ public static CompareNameQuery createQueryForNodesWithNameLessThanOrEqualTo(Path.Segment constraintValue, String localNameField, String snsIndexFieldName, ValueFactories factories, boolean caseSensitive, boolean includeSns) { return new CompareNameQuery(localNameField, snsIndexFieldName, constraintValue, factories.getPathFactory(), factories.getStringFactory(), factories.getLongFactory(), includeSns ? IS_LESS_THAN_OR_EQUAL_TO : IS_LESS_THAN_OR_EQUAL_TO_NO_SNS, caseSensitive); } private final String snsIndexFieldName; private final ValueFactory<Long> longFactory; private final PathFactory pathFactory; private final boolean caseSensitive; /** * Construct a {@link Query} implementation that scores nodes according to the supplied comparator. * * @param localNameField the name of the document field containing the local name value; may not be null * @param snsIndexFieldName the name of the document field containing the same-name-sibling index; may not be null * @param constraintValue the constraint path; may not be null * @param pathFactory the path factory that can be used during the scoring; may not be null * @param stringFactory the string factory that can be used during the scoring; may not be null * @param longFactory the long factory that can be used during the scoring; may not be null * @param evaluator the {@link CompareQuery.Evaluator} implementation that returns whether the node path satisfies the * constraint; may not be null * @param caseSensitive true if the comparison should be done in a case-sensitive manner, or false if it is to be * case-insensitive */ protected CompareNameQuery(final String localNameField, final String snsIndexFieldName, Path.Segment constraintValue, PathFactory pathFactory, ValueFactory<String> stringFactory, ValueFactory<Long> longFactory, Evaluator<Path.Segment> evaluator, boolean caseSensitive) { super(localNameField, constraintValue, null, stringFactory, evaluator, new FieldSelector() { private static final long serialVersionUID = 1L; @Override public FieldSelectorResult accept(String fieldName) { if (fieldName.equals(localNameField)) return FieldSelectorResult.LOAD; if (fieldName.equals(snsIndexFieldName)) return FieldSelectorResult.LOAD; return FieldSelectorResult.NO_LOAD; } }); this.snsIndexFieldName = snsIndexFieldName; this.longFactory = longFactory; this.pathFactory = pathFactory; this.caseSensitive = caseSensitive; assert this.snsIndexFieldName != null; assert this.longFactory != null; } /** * {@inheritDoc} * * @see org.modeshape.search.lucene.query.CompareQuery#readFromDocument(org.apache.lucene.index.IndexReader, int) */ @Override protected Path.Segment readFromDocument(IndexReader reader, int docId) throws IOException { Document doc = reader.document(docId, fieldSelector); String localName = doc.get(fieldName); if (!caseSensitive) localName = localName.toLowerCase(); int sns = longFactory.create(doc.get(snsIndexFieldName)).intValue(); return pathFactory.createSegment(localName, sns); } /** * {@inheritDoc} * * @see org.apache.lucene.search.Query#clone() */ @Override public Object clone() { return new CompareNameQuery(fieldName, snsIndexFieldName, constraintValue, pathFactory, stringFactory, longFactory, evaluator, caseSensitive); } }