com.mathworks.xzheng.advsearching.SortingExample.java Source code

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Here is the source code for com.mathworks.xzheng.advsearching.SortingExample.java

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package com.mathworks.xzheng.advsearching;

/**
 * Copyright Manning Publications Co.
 *
 * Licensed 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 lan      
*/

import java.io.IOException;
import java.io.PrintStream;
import java.text.DecimalFormat;

import org.apache.lucene.analysis.standard.StandardAnalyzer;
import org.apache.lucene.document.Document;
import org.apache.lucene.index.DirectoryReader;
import org.apache.lucene.queryparser.classic.QueryParser;
import org.apache.lucene.search.BooleanClause;
import org.apache.lucene.search.BooleanQuery;
import org.apache.lucene.search.IndexSearcher;
import org.apache.lucene.search.MatchAllDocsQuery;
import org.apache.lucene.search.Query;
import org.apache.lucene.search.ScoreDoc;
import org.apache.lucene.search.Sort;
import org.apache.lucene.search.SortField;
import org.apache.lucene.search.TopDocs;
import org.apache.lucene.store.Directory;
import org.apache.lucene.util.Version;

import com.mathworks.xzheng.common.TestUtil;
import com.sleepycat.utilint.StringUtils;

// From chapter 5
public class SortingExample {
    private Directory directory;

    public SortingExample(Directory directory) {
        this.directory = directory;
    }

    public void displayResults(Query query, Sort sort) // #1
            throws IOException {
        IndexSearcher searcher = new IndexSearcher(DirectoryReader.open(directory));

        searcher.setDefaultFieldSortScoring(true, false); // #2

        TopDocs results = searcher.search(query, null, // #3
                20, sort); // #3

        System.out.println("\nResults for: " + // #4
                query.toString() + " sorted by " + sort);

        System.out.println(StringUtils.rightPad("Title", 30) + StringUtils.rightPad("pubmonth", 10)
                + StringUtils.center("id", 4) + StringUtils.center("score", 15));

        PrintStream out = new PrintStream(System.out, true, "UTF-8"); // #5

        DecimalFormat scoreFormatter = new DecimalFormat("0.######");
        for (ScoreDoc sd : results.scoreDocs) {
            int docID = sd.doc;
            float score = sd.score;
            Document doc = searcher.doc(docID);
            out.println(StringUtils.rightPad( // #6
                    StringUtils.abbreviate(doc.get("title"), 29), 30) + // #6
                    StringUtils.rightPad(doc.get("pubmonth"), 10) + // #6
                    StringUtils.center("" + docID, 4) + // #6
                    StringUtils.leftPad( // #6
                            scoreFormatter.format(score), 12)); // #6
            out.println("   " + doc.get("category"));
            //out.println(searcher.explain(query, docID));   // #7
        }

    }

    /*
      The Sort object (#1) encapsulates an ordered collection of
      field sorting information. We ask IndexSearcher (#2) to
      compute scores per hit. Then we call the overloaded search
      method that accepts the custom Sort (#3). We use the
      useful toString method (#4) of the Sort class to describe
      itself, and then create PrintStream that accepts UTF-8
      encoded output (#5), and finally use StringUtils (#6) from
      Apache Commons Lang for nice columnar output
      formatting. Later you will see a reason to look at the
      explanation of score . For now, it's commented out (#7).
    */

    public static void main(String[] args) throws Exception {
        Query allBooks = new MatchAllDocsQuery();

        QueryParser parser = new QueryParser(Version.LUCENE_46, // #1
                "contents", // #1
                new StandardAnalyzer( // #1
                        Version.LUCENE_46)); // #1
        BooleanQuery query = new BooleanQuery(); // #1
        query.add(allBooks, BooleanClause.Occur.SHOULD); // #1
        query.add(parser.parse("java OR action"), BooleanClause.Occur.SHOULD); // #1

        Directory directory = TestUtil.getBookIndexDirectory(); // #2
        SortingExample example = new SortingExample(directory); // #2

        example.displayResults(query, Sort.RELEVANCE);

        example.displayResults(query, Sort.INDEXORDER);

        example.displayResults(query, new Sort(new SortField("category", SortField.STRING)));

        example.displayResults(query, new Sort(new SortField("pubmonth", SortField.INT, true)));

        example.displayResults(query, new Sort(new SortField("category", SortField.STRING), SortField.FIELD_SCORE,
                new SortField("pubmonth", SortField.INT, true)));

        example.displayResults(query,
                new Sort(new SortField[] { SortField.FIELD_SCORE, new SortField("category", SortField.STRING) }));
        directory.close();
    }
}

/*
#1 Create test query
#2 Create example running
*/