The default that is used if the parameter is not given is 0.5. The value is between 0 and 1, with a value closer to 1 only terms with a higher similarity will be matched. Starting with Lucene 1.9 an additional (optional) parameter can specify the required similarity. This search will find terms like foam and roams. For example to search for a term similar in spelling to 'roam' use the fuzzy search: roam~ To do a fuzzy search use the tilde, '~', symbol at the end of a Single word Term.

Lucene supports fuzzy searches based on the Levenshtein Distance, or Edit Distance algorithm. Note: You cannot use a * or ? symbol as the first character of a search. You can also use the wildcard searches in the middle of a term. For example, to search for test, tests or tester, you can use the search: test* Multiple character wildcard searches looks for 0 or more characters.

For example, to search for 'text' or 'test' you can use the search: te?t The single character wildcard search looks for terms that match that with the single character replaced. To perform a multiple character wildcard search use the '*' symbol. To perform a single character wildcard search use the '?' symbol. Lucene supports single and multiple character wildcard searches. Here is a BooleanQuery based on the query snippet.Lucene supports modifying query terms to provide a wide range of searching options. The BooleanQuery is a bit of a special case because it is a Query container that aggregates other queries (including nested BooleanQuerys for sophisticated expressions). Levenshtein algorithm for closeness matching.Īggregates other Query instances into complex expressions allowing AND, OR, and NOT logic.Īll of these Query implementations are in the package. Matches all terms that begin with a specified string. Lightweight, regular-expression-like term-matching syntax. Matches documents with terms between beginning and ending terms, including or excluding the end points. Single term query, which effectively is a single word.Ī match of several terms in order, or in near vicinity to one another. The relevant subclasses, their purpose, and some example expressions for each are listed in the following table: We need some understanding of the underlying concrete Query subclasses. When a human-readable query is parsed by Lucene’s QueryParser, it is converted to a single concrete subclass of the Query class. For example DateTime: ModificationDate:>’ 12:00:00′ We will explain searching operations on these fields in a later section. There are a few special field types that have their own syntax for defining the query term. Any existing field name can be used as field name. Then there’s BooleanQuery, PhraseQuery, and many other Query subclasses to choose from.įields When performing a search we can specify the field you want to search in. With Lucene Java, TermQuery is the most primitive Query. Multiple terms can be combined together with Boolean operators to form a more complex query. A Phrase is a group of words surrounded by double quotes such as “welcome lucene”. A Single Term is a single word such as “test” or “sample”. Terms are of two types: 1.Single Terms and 2.Phrases. A query is broken up into terms and operators. Lucene has a custom query syntax for querying its indexes.

In this chapter we will talk about the Lucene queries. We also have built up a small search application using lucene indexing & searching procedures. In a previous chapter we have learned the different components of the Lucene search engine. Table Of Contents 1.Introduction 2.Lucene Queries 3.Lucene Query API 4.Basic search 4.1.Terms 4.2.WildcardQuery 4.3.Boolean Operators 4.3.Grouping 4.4.PhraseQuery 4.5.RangeQuery 4.6.Prefix Query 4.7.Fuzzy Query 1.Introduction

Apache lucene query example