1. 首先，派生MethodIntercepter接口，override intercept方法，在调用目标类方法的前后加上额外的逻辑
2. 其次，使用Enhancer对象注册目标类和代理类，动态生成代理对象

public class SomeBase{
  public void someMethod(){
    System.out.println("call SomeBase.someMethod");
  }
}

public class SomeProxy implement MethodInterceptor{
  @Override
  public Object intercept(Object object, Method method, Object[] args, MethodProxy proxy) throws Throwable{
    System.out.println("Before calling SomeBase.someMethod");
    proxy.invokeSuper(object, args);
    System.out.println("After calling SomeBase.someMethod ");
  }
}

public class Test{
  public static void main(String[] args){
   Enhancer enhancer = new Enhancer();
    enhancer.setSuperclass(SomeBase.class);

    SomeProxy proxy = new SomeProxy();
    enhancer.setCallback(proxy);

    SomeBase base = (SomeBase)enhancer.create();

    base.someMethod(); 
  }
}