org.hibernate.search.query.dsl.impl.Helper.java Source code

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Here is the source code for org.hibernate.search.query.dsl.impl.Helper.java

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/*
 * Hibernate, Relational Persistence for Idiomatic Java
 *
 * Copyright (c) 2010, Red Hat, Inc. and/or its affiliates or third-party contributors as
 * indicated by the @author tags or express copyright attribution
 * statements applied by the authors.  All third-party contributions are
 * distributed under license by Red Hat, Inc.
 *
 * This copyrighted material is made available to anyone wishing to use, modify,
 * copy, or redistribute it subject to the terms and conditions of the GNU
 * Lesser General Public License, as published by the Free Software Foundation.
 *
 * This program 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 distribution; if not, write to:
 * Free Software Foundation, Inc.
 * 51 Franklin Street, Fifth Floor
 * Boston, MA  02110-1301  USA
 */

package org.hibernate.search.query.dsl.impl;

import java.io.IOException;
import java.io.Reader;
import java.io.StringReader;
import java.util.ArrayList;
import java.util.List;

import org.apache.lucene.analysis.Analyzer;
import org.apache.lucene.analysis.TokenStream;
import org.apache.lucene.analysis.tokenattributes.TermAttribute;

import org.hibernate.annotations.common.AssertionFailure;
import org.hibernate.search.SearchException;
import org.hibernate.search.engine.spi.DocumentBuilderIndexedEntity;
import org.hibernate.search.engine.spi.EntityIndexBinder;
import org.hibernate.search.engine.spi.SearchFactoryImplementor;

/**
 * @author Emmanuel Bernard
 */
class Helper {
    /**
     * return the analyzed value for a given field. If several terms are created, an exception is raised.
     */
    static String getAnalyzedTerm(String fieldName, String value, String name, Analyzer queryAnalyzer,
            FieldContext fieldContext) {
        if (fieldContext.isIgnoreAnalyzer())
            return value;

        try {
            final List<String> termsFromText = getAllTermsFromText(fieldName, value.toString(), queryAnalyzer);
            if (termsFromText.size() > 1) {
                StringBuilder error = new StringBuilder("The ").append(name)
                        .append(" parameter leads to several terms when analyzed: ");
                for (String term : termsFromText) {
                    error.append(term).append(", ");
                }
                final int length = error.length();
                throw new SearchException(error.delete(length - 1, length).toString());
            }
            return termsFromText.size() == 0 ? null : termsFromText.get(0);
        } catch (IOException e) {
            throw new AssertionFailure("IO exception while reading String stream??", e);
        }
    }

    static List<String> getAllTermsFromText(String fieldName, String localText, Analyzer analyzer)
            throws IOException {
        List<String> terms = new ArrayList<String>();

        // Can't deal with null at this point. Likely returned by some FieldBridge not recognizing the type.
        if (localText == null) {
            throw new SearchException("Search parameter on field " + fieldName + " could not be converted. "
                    + "Are the parameter and the field of the same type?"
                    + "Alternatively, apply the ignoreFieldBridge() option to " + "pass String parameters");
        }
        Reader reader = new StringReader(localText);
        TokenStream stream = analyzer.reusableTokenStream(fieldName, reader);
        TermAttribute attribute = stream.addAttribute(TermAttribute.class);
        stream.reset();

        while (stream.incrementToken()) {
            if (attribute.termLength() > 0) {
                String term = attribute.term();
                terms.add(term);
            }
        }
        stream.end();
        stream.close();
        return terms;
    }

    static DocumentBuilderIndexedEntity<?> getDocumentBuilder(QueryBuildingContext queryContext) {
        final SearchFactoryImplementor factory = queryContext.getFactory();
        final Class<?> type = queryContext.getEntityType();
        EntityIndexBinder<?> indexBinding = factory.getIndexBindingForEntity(type);
        if (indexBinding == null) {
            throw new AssertionFailure("Class in not indexed: " + type);
        }
        return indexBinding.getDocumentBuilder();
    }
}