Apache Lucene 6.0.0 发布了，一些提升：
* Java 8 is the minimum Java version required.
* Dimensional points, replacing legacy numeric fields, provides fast and
space-efficient support for both single- and multi-dimension range and
shape filtering. This includes numeric (int, float, long, double),
InetAddress, BigInteger and binary range filtering, as well as geo-spatial
shape search over indexed 2D LatLonPoints. See
https://www.elastic.co/blog/lucene-points-6.0 for details. Dependent
classes and modules (e.g., MemoryIndex, Spatial Strategies, Join module)
have been refactored to use new point types.
* Lucene classification module now works on Lucene Documents using a
KNearestNeighborClassifier or SimpleNaiveBayesClassifier.
* The spatial module no longer depends on third-party libraries. Previous
spatial classes have been moved to a new spatial-extras module.
* Spatial4j has been updated to a new 0.6 version hosted by locationtech.
* TermsQuery performance boost by a more aggressive default query caching
policy.
* IndexSearcher's default Similarity is now changed to BM25Similarity.
* Easier method of defining custom CharTokenizer instances. 下载地址：http://lucene.apache.org/core/mirrors-core-latest-redir.html
Lucene
是apache软件基金会一个开放源代码的全文检索引擎工具包，是一个全文检索引擎的架构，提供了完整的查询引擎和索引引擎，部分文本分析引擎。
Lucene的目的是为软件开发人员提供一个简单易用的工具包，以方便的在目标系统中实现全文检索的功能，或者是以此为基础建立起完整的全文检索引擎。 Lucene
最初是由Doug
Cutting所撰写的，是一位资深全文索引/检索专家，曾经是V-Twin搜索引擎的主要开发者，后来在Excite担任高级系统架构设计师，目前从事
于一些INTERNET底层架构的研究。他贡献出Lucene的目标是为各种中小型应用程式加入全文检索功能。 | 
