Spring aop considerations

Spring aop has JDK dynamic proxy and CGLIB, and can also use ASPECTJ.

Its JDK dynamic proxy is the interface proxy, while cglib is the proxy for the class. AspectJ is woven into the source code class.

The cglib proxy is used to call the constructor of the target object twice. JDK dynamic proxy and aspectJ are called only once.

In this way, when the cglib proxy is used and the default no-argument constructor of the target object is used for Resource Initialization, initialization may occur twice (based on the business scenario, it is assumed that only one Initialization is allowed ).

Test code:

Configure aop in xml:

Id = "loggerPointcutOfService"/>

In the class B constructor, the output is:

In B construtor

When calling the corresponding method of code object B:

Output:

In B construtor

In B construtor