我想为我的用户提供最相关和最好的结果。例如，我奖励具有大标题、描述、附加照片等的记录。对于上下文:记录是自行车路线，具有路线点(坐标)和照片、评论等元数据。

现在，我使用 Hibernate 为这些记录编制了索引，然后在 Hibernate Search 中使用 Lucene 在索引中进行搜索。为了对我的结果进行评分，我根据文档属性构建查询并在 should BooleanJunction 子句 中提升它们(使用 boostedTo()):

bj.should(qb.range().onField("descriptionLength").above(3000).createQuery()).boostedTo(3.0f);   
bj.should(qb.range().onField("views.views").above(5000).createQuery()).boostedTo(3.0f);     
bj.should(qb.range().onField("nameLength").above(20).createQuery()).boostedTo(1.0f);     
bj.should(qb.range().onField("picturesLength").above(0).createQuery()).boostedTo(5.0f);
bj.should(qb.keyword().onField("routePoints.poi.participant").matching("true").createQuery()).boostedTo(10.0f);

为了尝试禁用 Lucene 的评分，我覆盖了 DefaultSimilarity 类，将所有比较设置为 1.0f 评分并通过 Hibernate 配置启用它:

public class IgnoreScoringSimilarity extends DefaultSimilarity {
    @Override
    public float idf(long docFreq, long numDocs) {
        return 1.0f;
    }

    @Override
    public float tf(float freq) {
        return 1.0f;
    }

    @Override
    public float coord(int overlap, int maxOverlap) {
        return 1.0f;
    }

    @Override
    public float lengthNorm(FieldInvertState state) {
        return 1.0f;
    }

    @Override
    public float queryNorm(float sumOfSquaredWeights) {
        return 1.0f;
    }
} 

hibernate 配置:

<property name="hibernate.search.default.similarity" value="com.search.IgnoreScoringSimilarity"/>

这种方法在 90% 的时间里都有效，但是，我仍然看到一些似乎不合适的奇怪结果。我认识的模式是这些路线(文件)的尺寸非常大。一条正常的路线有大约 20-30 个路线点，但是这些不合适的结果有 100-150 个。这让我相信默认的 Lucene 评分仍在发生(由于文档大小，评分更高)。

我在禁用 Lucene 的评分方面做错了什么吗？能有别的解释吗？

最佳答案

我可以建议另一种基于自定义结果排序的方法。您可以在 answer 中阅读相关信息.这个答案有点过时，所以我根据 Lucene API 4.10.1 修改了这个例子。比较器

public abstract class CustomComparator extends FieldComparator<Double> {
    double[] scoring;
    double bottom;
    double topValue;
    private FieldCache.Ints[] currentReaderValues;
    private String[] fields;

    protected abstract double getScore(int[] value);

    public CustomComparator(int hitNum, String[] fields) {
        this.fields = fields;
        scoring = new double[hitNum];
    }

    int[] fromReaders(int doc) {
        int[] result = new int[currentReaderValues.length];
        for (int i = 0; i < result.length; i++) {
            result[i] = currentReaderValues[i].get(doc);
        }
        return result;
    }

    @Override
    public int compare(int slot1, int slot2) {
        return Double.compare(scoring[slot1], scoring[slot2]);
    }

    @Override
    public void setBottom(int slot) {
        this.bottom = scoring[slot];
    }

    @Override
    public void setTopValue(Double top) {
        topValue = top;
    }

    @Override
    public int compareBottom(int doc) throws IOException {
        double v2 = getScore(fromReaders(doc));
        return Double.compare(bottom, v2);
    }

    @Override
    public int compareTop(int doc) throws IOException {
        double docValue = getScore(fromReaders(doc));
        return Double.compare(topValue, docValue);
    }

    @Override
    public void copy(int slot, int doc) throws IOException {
        scoring[slot] = getScore(fromReaders(doc));
    }

    @Override
    public FieldComparator<Double> setNextReader(AtomicReaderContext atomicReaderContext) throws IOException {
        currentReaderValues = new FieldCache.Ints[fields.length];
        for (int i = 0; i < fields.length; i++) {
            currentReaderValues[i] = FieldCache.DEFAULT.getInts(atomicReaderContext.reader(), fields[i], null, false);
        }
        return this;
    }

    @Override
    public Double value(int slot) {
        return scoring[slot];
    }
}

搜索示例

public class SortExample {

    public static void main(String[] args) throws IOException {

        final String[] fields = new String[]{"descriptionLength", "views.views", "nameLength"};

        Sort sort = new Sort(
                new SortField(
                        "",
                        new FieldComparatorSource() {
                            public FieldComparator newComparator(String fieldname, int numHits, int sortPos, boolean reversed) throws IOException {
                                return new CustomComparator(numHits, fields) {
                                    @Override
                                    protected double getScore(int[] value) {
                                        int descriptionLength = value[0];
                                        int views = value[1];
                                        int nameLength = value[2];
                                        return -((descriptionLength > 2000.0 ? 5.0 : 0.0) +
                                                (views > 5000.0 ? 3.0 : 0.0) +
                                                (nameLength > 20.0 ? 1.0 : 0.0));
                                    }
                                };
                            }
                        }
                )
        );

        IndexWriterConfig indexWriterConfig = new IndexWriterConfig(Version.LUCENE_4_10_4, new StandardAnalyzer());
        Directory directory = new RAMDirectory();
        IndexWriter indexWriter = new IndexWriter(directory, indexWriterConfig);

        addDoc(indexWriter, "score 0", 1000, 1000, 10);
        addDoc(indexWriter, "score 5", 3000, 1000, 10);
        addDoc(indexWriter, "score 3", 1000, 6000, 10);
        addDoc(indexWriter, "score 1", 1000, 1000, 30);
        addDoc(indexWriter, "score 4", 1000, 6000, 30);
        addDoc(indexWriter, "score 6", 5000, 1000, 30);
        addDoc(indexWriter, "score 9", 5000, 6000, 30);

        final IndexReader indexReader = DirectoryReader.open(indexWriter, false);
        IndexSearcher indexSearcher = new IndexSearcher(indexReader);
        Query query = new TermQuery(new Term("all", "all"));
        int nDocs = 100;

        final TopDocs search = indexSearcher.search(query, null, nDocs, sort);
        System.out.println("Max " + search.scoreDocs.length + " " + search.getMaxScore());
        for (ScoreDoc sd : search.scoreDocs) {
            Document document = indexReader.document(sd.doc);
            System.out.println(document.getField("name").stringValue());
        }

    }

    private static void addDoc(IndexWriter indexWriter, String name, int descriptionLength, int views, int nameLength) throws IOException {
        Document doc = new Document();
        doc.add(new TextField("name", name, Field.Store.YES));
        doc.add(new TextField("all", "all", Field.Store.YES));
        doc.add(new IntField("descriptionLength", descriptionLength, Field.Store.YES));
        doc.add(new IntField("views.views", views, Field.Store.YES));
        doc.add(new IntField("nameLength", nameLength, Field.Store.YES));
        indexWriter.addDocument(doc);
    }
}

代码会输出

score 9
score 6
score 5
score 4
score 3
score 1
score 0

关于java - 如何在 Hibernate Search/Lucene 中禁用默认评分/提升？，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/30708833/