Example usage for org.apache.lucene.queries.mlt MoreLikeThis getFieldNames

Introduction

In this page you can find the example usage for org.apache.lucene.queries.mlt MoreLikeThis getFieldNames.

Prototype

public String[] getFieldNames() 

Source Link

Document

Returns the field names that will be used when generating the 'More Like This' query.

Usage

From source file:org.apache.jackrabbit.oak.plugins.index.lucene.util.MoreLikeThisHelper.java

License:Apache License

public static Query getMoreLikeThis(IndexReader reader, Analyzer analyzer, String mltQueryString) {
    Query moreLikeThisQuery = null;
    MoreLikeThis mlt = new MoreLikeThis(reader);
    mlt.setAnalyzer(analyzer);/*from w  ww.j a v a 2  s . co m*/
    try {
        String text = null;
        String[] fields = {};
        for (String param : mltQueryString.split("&")) {
            String[] keyValuePair = param.split("=");
            if (keyValuePair.length != 2 || keyValuePair[0] == null || keyValuePair[1] == null) {
                throw new RuntimeException("Unparsable native Lucene MLT query: " + mltQueryString);
            } else {
                if ("stream.body".equals(keyValuePair[0])) {
                    text = keyValuePair[1];
                } else if ("mlt.fl".equals(keyValuePair[0])) {
                    fields = keyValuePair[1].split(",");
                } else if ("mlt.mindf".equals(keyValuePair[0])) {
                    mlt.setMinDocFreq(Integer.parseInt(keyValuePair[1]));
                } else if ("mlt.mintf".equals(keyValuePair[0])) {
                    mlt.setMinTermFreq(Integer.parseInt(keyValuePair[1]));
                } else if ("mlt.boost".equals(keyValuePair[0])) {
                    mlt.setBoost(Boolean.parseBoolean(keyValuePair[1]));
                } else if ("mlt.qf".equals(keyValuePair[0])) {
                    mlt.setBoostFactor(Float.parseFloat(keyValuePair[1]));
                } else if ("mlt.maxdf".equals(keyValuePair[0])) {
                    mlt.setMaxDocFreq(Integer.parseInt(keyValuePair[1]));
                } else if ("mlt.maxdfp".equals(keyValuePair[0])) {
                    mlt.setMaxDocFreqPct(Integer.parseInt(keyValuePair[1]));
                } else if ("mlt.maxntp".equals(keyValuePair[0])) {
                    mlt.setMaxNumTokensParsed(Integer.parseInt(keyValuePair[1]));
                } else if ("mlt.maxqt".equals(keyValuePair[0])) {
                    mlt.setMaxQueryTerms(Integer.parseInt(keyValuePair[1]));
                } else if ("mlt.maxwl".equals(keyValuePair[0])) {
                    mlt.setMaxWordLen(Integer.parseInt(keyValuePair[1]));
                } else if ("mlt.minwl".equals(keyValuePair[0])) {
                    mlt.setMinWordLen(Integer.parseInt(keyValuePair[1]));
                }
            }
        }
        if (text != null) {
            if (FieldNames.PATH.equals(fields[0])) {
                IndexSearcher searcher = new IndexSearcher(reader);
                TermQuery q = new TermQuery(new Term(FieldNames.PATH, text));
                TopDocs top = searcher.search(q, 1);
                if (top.totalHits == 0) {
                    mlt.setFieldNames(fields);
                    moreLikeThisQuery = mlt.like(new StringReader(text), mlt.getFieldNames()[0]);
                } else {
                    ScoreDoc d = top.scoreDocs[0];
                    Document doc = reader.document(d.doc);
                    List<String> fieldNames = new ArrayList<String>();
                    for (IndexableField f : doc.getFields()) {
                        if (!FieldNames.PATH.equals(f.name())) {
                            fieldNames.add(f.name());
                        }
                    }
                    String[] docFields = fieldNames.toArray(new String[fieldNames.size()]);
                    mlt.setFieldNames(docFields);
                    moreLikeThisQuery = mlt.like(d.doc);
                }
            } else {
                mlt.setFieldNames(fields);
                moreLikeThisQuery = mlt.like(new StringReader(text), mlt.getFieldNames()[0]);
            }
        }
        return moreLikeThisQuery;
    } catch (Exception e) {
        throw new RuntimeException("could not handle MLT query " + mltQueryString);
    }
}

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