Recently, I have been reading geoserver. Because geoserver manages data processing by geotools, geotools is involved. Currently, the stable version of geoserver is 2.0.2. After deploying geoserver in Tomcat, you can find GT-? In the web-info directory of the geoserver project -? -2.6.4 indicates that geoserver uses a jar package written in geotools2.6.4 in this version.
Download the following package from the official website: geotools-2.6.4-bin.zip,geotools-2.6.4-project.zip,geotools-2.6.4-doc.zip. After decompression, we can find that there are a bunch of jar packages in the bin, which are exactly what geotools depends on in the project, you only need to load the corresponding jar as needed. The project does not need to be decompressed, but is added when the source code is associated, you can see the source code explanation of geotools. The doc is the javadoc of geotools.
The demo directory of the project contains example for your reference. For example, you can copy Quickstart. Java to your project file and run it to easily read a SHP file.
Geotools, from here on, there are many to learn!
This document reference: http://docs.codehaus.org/display/GEOTDOC/Home geotools official guide