Spring aop-caused By:java.lang.IllegalArgumentException:Superclass has no null constructors but no arguments were N

Today in the integration of PERF4J and Javasimon into the code to find some problems, that is, in their own test code to run good things, in the project code always reported the following error: ... caused By:java.lang.IllegalArgumentException:Superclass has no null constructors but no arguments were ... Comparing the code half day found that there were no spring beans with construction parameters in their own test code, and many of the classes in the project code were created by a parameter constructor. When spring creates the target object subclass with Cglib, it does not handle the parameter constructor, but instead uses the default my parameter constructor, which causes the above exception to appear. The easiest way to solve this problem is to add a default constructor, assuming your class allows you to modify it, but it's more cumbersome for classes that don't have a default constructor, such as a third party class. Here's a very detailed article describing the problem, http://netfork.javaeye.com/blog/286215