Web Crawler in Java

I have a task in which I have to scan the HTML source of web pages and extract some information depending upon the pattern. The extracted information will be save in the database for the business purpose. The amount of data being extracted in not much.

I am searching for an appropriate web crawler written in java.
Does anyone has some suggestion to give or any other inputs to be share.

Any kind of help is highly appreciated.

You can find crawlers at www.java-source.net. For extracting information, use a library like HtmlUnit.

Thanks Lester for the reply. I have selected few crawlers projects and have decided to try them making a small prototype of each.

I use httpclient for similar purposes...

Another option is to call wget command from java. It works fine when you have https

Its better to use perl for this kind of tasks. You have mechanize or LWP library on CPAN. HTMLUnit is too slow.

I think so you can try php examples firs, which you can find here:

http://broobee.com/folder/12/crawlers-applications