import org.apache.lucene.search.similarities.NormalizationH1; //导入依赖的package包/类
@Before
public void setupIndex() throws IOException {
    dirUnderTest = newDirectory();
    List<Similarity> sims = Arrays.asList(
            new ClassicSimilarity(),
            new SweetSpotSimilarity(), // extends Classic
            new BM25Similarity(),
            new LMDirichletSimilarity(),
            new BooleanSimilarity(),
            new LMJelinekMercerSimilarity(0.2F),
            new AxiomaticF3LOG(0.5F, 10),
            new DFISimilarity(new IndependenceChiSquared()),
            new DFRSimilarity(new BasicModelBE(), new AfterEffectB(), new NormalizationH1()),
            new IBSimilarity(new DistributionLL(), new LambdaDF(), new NormalizationH3())
        );
    similarity = sims.get(random().nextInt(sims.size()));

    indexWriterUnderTest = new RandomIndexWriter(random(), dirUnderTest, newIndexWriterConfig().setSimilarity(similarity));
    for (int i = 0; i < docs.length; i++) {
        Document doc = new Document();
        doc.add(newStringField("id", "" + i, Field.Store.YES));
        doc.add(newField("field", docs[i], Store.YES));
        indexWriterUnderTest.addDocument(doc);
    }
    indexWriterUnderTest.commit();
    indexWriterUnderTest.forceMerge(1);
    indexWriterUnderTest.flush();


    indexReaderUnderTest = indexWriterUnderTest.getReader();
    searcherUnderTest = newSearcher(indexReaderUnderTest);
    searcherUnderTest.setSimilarity(similarity);
}
 

import org.apache.lucene.search.similarities.NormalizationH1; //导入依赖的package包/类
static Normalization parseNormalization(String expr, String c, String mu, String z) {
  if (mu != null && !"H3".equals(expr)) {
    throw new RuntimeException(
        "parameter mu only makes sense for normalization H3");
  }
  if (z != null && !"Z".equals(expr)) {
    throw new RuntimeException(
        "parameter z only makes sense for normalization Z");
  }
  if (c != null && !("H1".equals(expr) || "H2".equals(expr))) {
    throw new RuntimeException(
        "parameter c only makese sense for normalizations H1 and H2");
  }
  if ("H1".equals(expr)) {
    return (c != null) ? new NormalizationH1(Float.parseFloat(c))
                       : new NormalizationH1();
  } else if ("H2".equals(expr)) {
    return (c != null) ? new NormalizationH2(Float.parseFloat(c))
                       : new NormalizationH2();
  } else if ("H3".equals(expr)) {
    return (mu != null) ? new NormalizationH3(Float.parseFloat(mu))
                        : new NormalizationH3();
  } else if ("Z".equals(expr)) {
    return (z != null) ? new NormalizationZ(Float.parseFloat(z))
                       : new NormalizationZ();
  } else if ("none".equals(expr)) {
    return new Normalization.NoNormalization();
  } else {
    throw new RuntimeException("Invalid normalization: " + expr);
  }
}