CGLIB is required to process @Configuration classes

Question

Am using Spring 3.1. War is not built using Maven. Its just a normal build. I have below jars in my class path.

antlr-runtime-3.0.1.jar
commons-logging-1.1.1.jar
org.apache.commons.logging.jar
org.springframework.aop-3.1.0.M2.jar
org.springframework.asm-3.1.0.M2.jar
org.springframework.aspects-3.1.0.M2.jar
org.springframework.beans-3.1.0.M2.jar
org.springframework.context-3.1.0.M2.jar
org.springframework.context.support-3.1.0.M2.jar
org.springframework.core-3.1.0.M2.jar
org.springframework.core-3.1.0.RELEASE.jar
org.springframework.core.jar
org.springframework.expression-3.1.0.M2.jar
spring-beans-3.0.5.RELEASE.jar
spring-context-3.0.5.RELEASE.jar

I have below code,

@Configuration
public class AppConfig {

    @Bean(name="helloBean")
    public HelloWorld helloWorld()
    {
        return new HelloWorldImpl();
    }
}

When I run main method, am getting below exception

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: [appConfig]
at org.springframework.context.annotation.ConfigurationClassPostProcessor.enhanceConfigurationClasses(ConfigurationClassPostProcessor.java:297)
at org.springframework.context.annotation.ConfigurationClassPostProcessor.processConfigurationClasses(ConfigurationClassPostProcessor.java:200)

To overcome this, if I add cglib-2.1.jar, am getting below exception..

java.lang.ClassNotFoundException: org.objectweb.asm.Type

To overcome this, if I add asm3.1.jar, am getting below exception.

java.lang.NoSuchMethodError: org.objectweb.asm.ClassWriter.

How can I overcome my initial exception - CGLIB is required to process @Configuration classes ?

Answer 1

War is not built using Maven. Its just a normal build

Your problem exactly highlights why you should use Maven (or other similar dependency tool) -- congratulation on learning things the hard way. Libraries in Java world often have a very complex dependency tree and Maven can help resolve it all for you.

In your case, had you used maven you just need to include cglib dependency and all its transitive dependency (including asm) will be resolved for you

<dependency>
    <groupId>cglib</groupId>
    <artifactId>cglib</artifactId>
    <version>3.0</version>
</dependency>

Answer 2

Starting with Spring 3.2, it is no longer necessary to add cglib as an explicit dependency.

Reference: http://www.baeldung.com/2011/10/20/bootstraping-a-web-application-with-spring-3-1-and-java-based-configuration-part-1/#cglib_gone

This answer for those who wondered why their project running normally without cglib, and come to this page searching for info about cglib as me.