Getting Started

Getting Lucene to work on your asp.net website isn't hard but there are a few tricks that help. We decided to use the Lucene.Net 2.1.0 release because it made updating the Lucene index easier via a new method on the IndexWriter object called UpdateDocument. This method deletes the specified document and then adds the new copy into the index. You can't download the Lucene.net 2.1.0 binary. Instead you will need to download the source via their subversion repository and then compile it.

Don't worry this is an easy step. Using your subversion client - I recommend TortiseSvn get the source by doing a checkout from this url: https://svn.apache.org/repos/asf/incubator/lucene.net/tags/Lucene.Net_2_1_0/

Next go into the directory: Lucene.Net_2_1_0\src\Lucene.Net You should find a Visual Studio solution file that matches your Visual Studio version. If you are using Visual Studio 2005 be sure to load Lucene.Net-2.1.0-VS2005.sln

Hit compile. The resulting Lucene.Net.dll in the bin/release folder is the dll you will need to reference in your Visual Studio project that will contain the Lucene code.

Creating the Lucene Index

Lucene creates a file based index that it uses to quickly return search results. We had to find a way to index all the pages in our system so that Lucene would have a way to search all of our content. In our case this includes all the articles, forum posts and of course house plans on the website. To make this happen we query our database, get back urls to all of our content and then send a webspider out to pull down the content from our site. That content is then parsed and fed to Lucene.

We developed three classes to make this all work. Most of the code is taken from examples or other kind souls who shared code. The first class, GeneralSearch.cs creates the index and provides the mechanism for searching it. The second class, HtmlDocument consists of code taken from Searcharoo a web spidering project written in C#. The HtmlDocument class handles parsing the html for us. Special thanks to Searcharoo for that code. I didn't want to write it. The last class is also borrowed from Searcharoo. It is called HtmlDownloader.cs and its task is to download pages from the site and then create a HtmlDocument from them.

References:

• Apache Lucene.Net 2.1 Class Library API
• Searcharoo