Lucene in Action [Paperback]

Lucene is an open source, search engine library that provides a sophisticated API that can be used to index documents and provide advanced search capabilities. Although using Lucene is not particularly difficult, like many open source projects, the available documentation leaves something to be desired. This book nicely fills that missing area.

The book starts with an introduction explaining both what Lucene is and also what it isn't. The next couple of chapters show us how to use the Lucene classes to index documents and then search for those documents. The authors next show us how to improve our searches by using different analyzers including how to write our own custom analyzers. Custom analyzers can allow, for example, searches using common misspellings or words that sound alike. The book moves on to look at the advanced search features that are available to the developer as well as explaining how to add your own features into Lucene. Since Lucene works only with text data, the authors next show us how to convert various data formats such as Word documents, HTML documents, and PDFs into text formats to allow Lucene to index and search them. The authors wrap up the main portion of the book with a look at some of the tools and extensions available that can provide some nice additional functionality such as highlighting search words in the found documents. The final chapter is a look at some real-life case studies of Lucene contributed by various authors. Some of the writing here is rather weak and seems, at least in some cases, to be little more than ads for the various sites and products.

The book is very well written and gives a good in-depth exploration of Lucene. The authors give plenty of code snippets showing the features of Lucene and provide a complete application to review as well. Anyone interested in using Lucene and wants more than the little documentation available should consider getting this book. One thing that annoyed me about the book was the constant pushing of JUnit. Most of the code samples include some traces of unit testing and seeing blocks of code with "assertEquals" everywhere was distracting to say the least. The authors should have considered that not everyone is using JUnit and that when you are trying to understand code, additional off-topic lines are simply confusing.

Lucene is truly an amazing piece of work. A knowledgeable Java programmer can pick up the API and integrate lucene into their applications very quickly and effectively. There are some excellent examples that come with system, and getting an index built and a search system working is a fun task you can complete in a short afternoon.

There are, however, some conceptual hurdles. Lucene aims to be, and is, an excellent search engine, and nothing more. Surrounding Lucene are a number of other projects and tools for parsing documents, extracting blurbs, highlight results, and so on. On the flip side, Lucene it's self is amazingly configurable. Out of the box is has some excellent defaults, but you can change every aspect of the system.

The "Lucene in Action" book can provide you with the big picture. The book provides excellent examples and give you pointers that will save you time, and make you look (and feel) like you have been developing search systems your whole life. I have the Lucene in Action book now, and I'm using it to re-factor my software application. Had I owned the book at the beginning of my project, I would be six months ahead of where I am today.

This is a solid, well-written, introduction to Lucene and related technologies. The book starts with an introduction to the architecture of Lucene, replete with a simple sample application, then goes into an in-depth review of the indexing, searching and querying. XML and HTML indexing are also covered. As are performance issues. The last chapter covers related technologies and other implementations of Lucene into other languages.

This is the best book I have seen on Lucene. It's an informative, fun read, that is worth the money if Lucene is central to your application.