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.jcr.query.lucene; import java.io.IOException; import org.apache.lucene.document.Document; import org.apache.lucene.index.IndexReader; import org.apache.lucene.search.Query; import org.apache.lucene.search.Weight; import org.modeshape.jcr.query.lucene.CaseOperations.CaseOperation; import org.modeshape.jcr.value.Path; import org.modeshape.jcr.value.ValueComparators; import org.modeshape.jcr.value.ValueFactories; import org.modeshape.jcr.value.ValueFactory; /** * A Lucene {@link Query} implementation that is used to apply a {@link javax.jcr.query.qom.Comparison} constraint against the * Path 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 Paths that satisfy the * constraint. */ public class ComparePathQuery extends CompareQuery<Path> { private static final long serialVersionUID = 1L; protected static final Evaluator<Path> PATH_IS_LESS_THAN = new Evaluator<Path>() { private static final long serialVersionUID = 1L; @Override public boolean satisfiesConstraint(Path nodePath, Path constraintPath) { return ValueComparators.PATH_COMPARATOR.compare(nodePath, constraintPath) < 0; } @Override public String toString() { return " < "; } }; protected static final Evaluator<Path> PATH_IS_LESS_THAN_OR_EQUAL_TO = new Evaluator<Path>() { private static final long serialVersionUID = 1L; @Override public boolean satisfiesConstraint(Path nodePath, Path constraintPath) { return ValueComparators.PATH_COMPARATOR.compare(nodePath, constraintPath) <= 0; } @Override public String toString() { return " <= "; } }; protected static final Evaluator<Path> PATH_IS_GREATER_THAN = new Evaluator<Path>() { private static final long serialVersionUID = 1L; @Override public boolean satisfiesConstraint(Path nodePath, Path constraintPath) { return ValueComparators.PATH_COMPARATOR.compare(nodePath, constraintPath) > 0; } @Override public String toString() { return " > "; } }; protected static final Evaluator<Path> PATH_IS_GREATER_THAN_OR_EQUAL_TO = new Evaluator<Path>() { private static final long serialVersionUID = 1L; @Override public boolean satisfiesConstraint(Path nodePath, Path constraintPath) { return ValueComparators.PATH_COMPARATOR.compare(nodePath, constraintPath) >= 0; } @Override public String toString() { return " >= "; } }; /** * Construct a {@link Query} implementation that scores documents such that the node represented by the document has a path * that is greater than the supplied constraint path. * * @param constraintPath the constraint path; may not be null * @param fieldName the name of the document field containing the path value; may not be null * @param factories the value factories that can be used during the scoring; may not be null * @param caseOperation the operation that should be performed on the indexed values before the constraint value is being * evaluated; may not be null * @return the path query; never null */ public static ComparePathQuery createQueryForNodesWithPathGreaterThan(Path constraintPath, String fieldName, ValueFactories factories, CaseOperation caseOperation) { return new ComparePathQuery(fieldName, constraintPath, factories.getPathFactory(), factories.getStringFactory(), PATH_IS_GREATER_THAN, caseOperation); } /** * Construct a {@link Query} implementation that scores documents such that the node represented by the document has a path * that is greater than or equal to the supplied constraint path. * * @param constraintPath the constraint path; may not be null * @param fieldName the name of the document field containing the path value; may not be null * @param factories the value factories that can be used during the scoring; may not be null * @param caseOperation the operation that should be performed on the indexed values before the constraint value is being * evaluated; may not be null * @return the path query; never null */ public static ComparePathQuery createQueryForNodesWithPathGreaterThanOrEqualTo(Path constraintPath, String fieldName, ValueFactories factories, CaseOperation caseOperation) { return new ComparePathQuery(fieldName, constraintPath, factories.getPathFactory(), factories.getStringFactory(), PATH_IS_GREATER_THAN_OR_EQUAL_TO, caseOperation); } /** * Construct a {@link Query} implementation that scores documents such that the node represented by the document has a path * that is less than the supplied constraint path. * * @param constraintPath the constraint path; may not be null * @param fieldName the name of the document field containing the path value; may not be null * @param factories the value factories that can be used during the scoring; may not be null * @param caseOperation the operation that should be performed on the indexed values before the constraint value is being * evaluated; may not be null * @return the path query; never null */ public static ComparePathQuery createQueryForNodesWithPathLessThan(Path constraintPath, String fieldName, ValueFactories factories, CaseOperation caseOperation) { return new ComparePathQuery(fieldName, constraintPath, factories.getPathFactory(), factories.getStringFactory(), PATH_IS_LESS_THAN, caseOperation); } /** * Construct a {@link Query} implementation that scores documents such that the node represented by the document has a path * that is less than or equal to the supplied constraint path. * * @param constraintPath the constraint path; may not be null * @param fieldName the name of the document field containing the path value; may not be null * @param factories the value factories that can be used during the scoring; may not be null * @param caseOperation the operation that should be performed on the indexed values before the constraint value is being * evaluated; may not be null * @return the path query; never null */ public static ComparePathQuery createQueryForNodesWithPathLessThanOrEqualTo(Path constraintPath, String fieldName, ValueFactories factories, CaseOperation caseOperation) { return new ComparePathQuery(fieldName, constraintPath, factories.getPathFactory(), factories.getStringFactory(), PATH_IS_LESS_THAN_OR_EQUAL_TO, caseOperation); } private final CaseOperation caseOperation; /** * Construct a {@link Query} implementation that scores nodes according to the supplied comparator. * * @param fieldName the name of the document field containing the path value; may not be null * @param constraintPath the constraint path; may not be null * @param pathFactory the value 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 evaluator the {@link CompareQuery.Evaluator} implementation that returns whether the node path satisfies the * constraint; may not be null * @param caseOperation the operation that should be performed on the indexed values before the constraint value is being * evaluated; may not be null */ protected ComparePathQuery(String fieldName, Path constraintPath, ValueFactory<Path> pathFactory, ValueFactory<String> stringFactory, Evaluator<Path> evaluator, CaseOperation caseOperation) { super(fieldName, constraintPath, pathFactory, stringFactory, evaluator); this.caseOperation = caseOperation; } @Override protected Path readFromDocument(IndexReader reader, int docId) throws IOException { Document doc = reader.document(docId, fieldSelector); String valueString = doc.get(fieldName); if (valueString == null) return null; valueString = caseOperation.execute(valueString); return valueTypeFactory.create(valueString); } @Override public Object clone() { return new ComparePathQuery(fieldName, constraintValue, valueTypeFactory, stringFactory, evaluator, caseOperation); } }