使用Hibernate Search自动完成

Question

我正在尝试为我的网站构建更好的自动完成功能。 我想为此使用Hibernate Search，但据我实验，它只能为我找到完整的单词。

所以，我的问题是：是否可以仅搜索某些字符？

例如。 用户键入3个字母，然后使用休眠搜索向他显示我的db对象中包含这3个字母的所有单词？

PS。 现在，我正在为此使用“赞”查询...但是我的数据库增长了很多，我还想将搜索功能扩展到另一个表上...

Answer 1

重大修改一年后，我得以改进发布的原始代码以产生此效果：

我的索引实体：

@Entity
@Indexed
@AnalyzerDef(name = "myanalyzer",
// Split input into tokens according to tokenizer
tokenizer = @TokenizerDef(factory = WhitespaceTokenizerFactory.class), //
filters = { //
// Normalize token text to lowercase, as the user is unlikely to care about casing when searching for matches
@TokenFilterDef(factory = LowerCaseFilterFactory.class),
// Index partial words starting at the front, so we can provide Autocomplete functionality
@TokenFilterDef(factory = NGramFilterFactory.class, params = { @Parameter(name = "maxGramSize", value = "1024") }),
// Close filters & Analyzerdef
})
@Analyzer(definition = "myanalyzer")
public class Compound extends DomainObject {
public static String[] getSearchFields(){...}
...
}

所有@Field都被标记并存储在索引中； 工作所需的条件：
@Field(index = Index.TOKENIZED, store = Store.YES)

@Transactional(readOnly = true)
public synchronized List<String> getSuggestions(final String searchTerm) {
    // Compose query for term over all fields in Compound
    String lowerCasedSearchTerm = searchTerm.toLowerCase();

    // Create a fullTextSession for the sessionFactory.getCurrentSession()
    FullTextSession fullTextSession = Search.getFullTextSession(getSession());

    // New DSL based query composition
    SearchFactory searchFactory = fullTextSession.getSearchFactory();
    QueryBuilder buildQuery = searchFactory.buildQueryBuilder().forEntity(Compound.class).get();
    TermContext keyword = buildQuery.keyword();
    WildcardContext wildcard = keyword.wildcard();
    String[] searchfields = Compound.getSearchfields();
    TermMatchingContext onFields = wildcard.onField(searchfields[0]);
    for (int i = 1; i < searchfields.length; i++)
        onFields.andField(searchfields[i]);
    TermTermination matching = onFields.matching(input.toLowerCase());
    Query query = matching.createQuery();

    // Convert the Search Query into something that provides results: Specify Compound again to be future proof
    FullTextQuery fullTextQuery = fullTextSession.createFullTextQuery(query, Compound.class);
    fullTextQuery.setMaxResults(20);

    // Projection does not work on collections or maps which are indexed via @IndexedEmbedded
    List<String> projectedFields = new ArrayList<String>();
    projectedFields.add(ProjectionConstants.DOCUMENT);
    List<String> embeddedFields = new ArrayList<String>();
    for (String fieldName : searchfields)
        if (fieldName.contains("."))
            embeddedFields.add(fieldName);
        else
            projectedFields.add(fieldName);

    @SuppressWarnings("unchecked")
    List<Object[]> results = fullTextQuery.setProjection(projectedFields.toArray(new String[projectedFields.size()])).list();

    // Keep a list of suggestions retrieved by search over all fields
    List<String> suggestions = new ArrayList<String>();
    for (Object[] projectedObjects : results) {
        // Retrieve the search suggestions for the simple projected field values
        for (int i = 1; i < projectedObjects.length; i++) {
            String fieldValue = projectedObjects[i].toString();
            if (fieldValue.toLowerCase().contains(lowerCasedSearchTerm))
                suggestions.add(fieldValue);
        }

        // Extract the search suggestions for the embedded fields from the document
        Document document = (Document) projectedObjects[0];
        for (String fieldName : embeddedFields)
            for (Field field : document.getFields(fieldName))
                if (field.stringValue().toLowerCase().contains(lowerCasedSearchTerm))
                    suggestions.add(field.stringValue());
    }

    // Return the composed list of suggestions, which might be empty
    return suggestions;
}

最后，我正在做一些争吵来处理@IndexedEmbedded字段。 如果您没有这些，则可以简化整个代码，只需投影searchFields，而忽略文档和EmbeddedField处理。

和以前一样：希望这对下一个遇到此问题的人很有用。 如果有人对以上发布的代码有任何批评或改进，请随时进行编辑，并请告知我。

---

Edit3 ：此代码所来自的项目自此是开源的。 以下是相关的类：

https://trac.nbic.nl/metidb/browser/trunk/metidb/metidb-core/src/main/java/org/metidb/domain/Compound.java
https://trac.nbic.nl/metidb/browser/trunk/metidb/metidb-core/src/main/java/org/metidb/dao/CompoundDAOImpl.java
https://trac.nbic.nl/metidb/browser/trunk/metidb/metidb-search/src/main/java/org/metidb/search/text/Autocompleter.java

Answer 2

您可以按照此处建议使用NGramFilter对该字段建立索引。 为了获得最佳结果，您应该使用Apache Solr的EdgeNgramFilter ，它从术语的开始边缘开始创建ngram，也可以在休眠搜索中使用。

Answer 3

蒂姆的回答很出色，并帮助我克服了困难的部分。 对我来说，它仅适用于单个单词查询。 如果有人希望它使它适用于短语搜索。 只需将所有“术语”实例替换为其相应的“短语”类即可。 这是蒂姆的代码的替代行，这些代码对我有用。

// New DSL based query composition
            //org.hibernate.search.query.dsl
            SearchFactory searchFactory = fullTextSession.getSearchFactory();
            QueryBuilder buildQuery = searchFactory.buildQueryBuilder().forEntity(MasterDiagnosis.class).get();
            PhraseContext keyword = buildQuery.phrase();
            keyword.withSlop(3);
            //WildcardContext wildcard = keyword.wildcard();
            String[] searchfields = MasterDiagnosis.getSearchfields();
            PhraseMatchingContext onFields = keyword.onField(searchfields[0]);
            for (int i = 1; i < searchfields.length; i++)
                onFields.andField(searchfields[i]);
            PhraseTermination matching = onFields.sentence(lowerCasedSearchTerm);
            Query query = matching.createQuery();
 // Convert the Search Query into something that provides results: Specify Compound again to be future proof