title: ClassLoader does NOT provide an 'addTransformer(ClassFileTransformer)' method
body: <p>I'm using Spring and AspectJ to do some nice weaving and I just ran into this issue after inserting <code>&lt;context:load-time-weaver/&gt;</code> into my application context:</p>
  
  <pre><code>Caused by: java.lang.IllegalStateException: ClassLoader [sun.misc.Launcher$AppClassLoader] does NOT provide an 'addTransformer(ClassFileTransformer)' method. Specify a custom LoadTimeWeaver or start your Java virtual machine with Spring's agent: -javaagent:org.springframework.instrument.jar
      at org.springframework.context.weaving.DefaultContextLoadTimeWeaver.setBeanClassLoader(DefaultContextLoadTimeWeaver.java:83)
      at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.invokeAwareMethods(AbstractAutowireCapableBeanFactory.java:1419)
      at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1391)
      at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:513)
      ... 21 common frames omitted
  </code></pre>
  
  <p>Do I need a custom JVM to run AspectJ?!? I can't ever remember having to do this before.</p>