Java (programming language)

In this section we will learn about Spring cglib library and understand the importance of it. You will also find the url to download cglib library

What is cglib?

The cglib is high performance library in Java. It is used to extend Java classes and implement interfaces in runtime. It is one the best quality code generation library available in Java. The latest version of cglib library can be downloaded from

The cglib library is free software and can be used for personal and commercial purposes.

Spring 3 framework uses cglib2 for manipulating the Java classes in runtime. The cglib library is not included in Spring 3.0 distribution. So, you have to manually download and include in your project.

On the cglib home page you will find the link to download.

If you don’t include the cglib dependency in your Spring 3 project you might get the following error:

Jan 2, 2010 3:22:07 PM prepareRefresh

INFO: Refreshing org.springframework.context.annotation.AnnotationConfigApplicationContext@15eb0a9:
startup date [Sat Jan 02 15:22:07 IST 2010]; root of context hierarchy

Exception in thread “main” java.lang.IllegalStateException: CGLIB is required to process @Configuration classes.
Either add CGLIB to the classpath or remove the following @Configuration bean definitions: [spring3HelloWorldConfig]

at org.springframework.context.annotation.ConfigurationClassPost

at org.springframework.context.annotation.ConfigurationClass




at org.springframework.context.annotation.Annotation

at net.roseindia.Spring3HelloWorldConfigTest.main(

  1. […] Spring cglib ( […]

  2. […] Spring cglib ( […]

  3. […] Spring cglib ( […]

Leave a Reply

Please log in using one of these methods to post your comment: Logo

You are commenting using your account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s