com.mathworks.xzheng.tools.BooksMoreLikeThis.java Source code

Introduction

Here is the source code for com.mathworks.xzheng.tools.BooksMoreLikeThis.java

Source

package com.mathworks.xzheng.tools;

/**
 * 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.File;

import org.apache.lucene.document.Document;
import org.apache.lucene.index.IndexReader;
import org.apache.lucene.queries.mlt.MoreLikeThis;
import org.apache.lucene.search.IndexSearcher;
import org.apache.lucene.search.Query;
import org.apache.lucene.search.TopDocs;
import org.apache.lucene.store.FSDirectory;

// From chapter 8
public class BooksMoreLikeThis {
    public static void main(String[] args) throws Throwable {

        String indexDir = System.getProperty("index.dir");
        FSDirectory directory = FSDirectory.open(new File(indexDir));
        IndexReader reader = IndexReader.open(directory);

        IndexSearcher searcher = new IndexSearcher(reader);

        int numDocs = reader.maxDoc();

        MoreLikeThis mlt = new MoreLikeThis(reader); // #A
        mlt.setFieldNames(new String[] { "title", "author" });
        mlt.setMinTermFreq(1); // #B
        mlt.setMinDocFreq(1);

        for (int docID = 0; docID < numDocs; docID++) { // #C
            System.out.println();
            Document doc = reader.document(docID);
            System.out.println(doc.get("title"));

            Query query = mlt.like(docID); // #D
            System.out.println("  query=" + query);

            TopDocs similarDocs = searcher.search(query, 10);
            if (similarDocs.totalHits == 0)
                System.out.println("  None like this");
            for (int i = 0; i < similarDocs.scoreDocs.length; i++) {
                if (similarDocs.scoreDocs[i].doc != docID) { // #E
                    doc = reader.document(similarDocs.scoreDocs[i].doc);
                    System.out.println("  -> " + doc.getField("title").stringValue());
                }
            }
        }

        reader.close();
        directory.close();
    }
}

/*
  #A Instantiate MoreLikeThis
  #B Lower default minimums
  #C Iterate through all docs in the index
  #D Build query to find similar documents
  #E Don't show the same document
*/