使用plantUML绘制类图 ---cglib + jdk Proxy

动态代理

@startuml

note top of Proxy
  Proxy 代理类
  Object proxy = (Object)Proxy.newProxyInstance(obj.getClass().getClassLoader(), obj.getClass().getInterfaces(), handler);
  通过Proxy类的newProxyInstance方法创建代理对象，我们来看下方法中的参数
  第一个参数：people.getClass().getClassLoader()，使用handler对象的classloader对象来加载我们的代理对象
  第二个参数：people.getClass().getInterfaces()，这里为代理类提供的接口是真实对象实现的接口，这样代理对象就能像真实对象一样调用接口中的所有方法
  第三个参数：handler，我们将代理对象关联到上面的InvocationHandler对象上
end note

class Proxy implements Serializable{
	+ Object newProxyInstance(ClassLoader loader, Class<?>[] interfaces, InvocationHandler h)

Proxy +-- InvocationHandler
note top of InvocationHandler : 实现InvocationHandler接口，重写invoke方法。
interface InvocationHandler{
	+ Object invoke(Object proxy, Method method, Object[] args)
}


note top of Enhancer
  cglib Enhancer 代理 </br>
  Enhancer enhancer = new Enhancer();
  enhancer.setSuperclass(SampleClass.class);
  enhancer.setCallback(new MethodInterceptor() {
      @Override
      public Object intercept(Object obj, Method method, Object[] args, MethodProxy proxy) throws Throwable {
         System.out.println("before method run...");
         Object result = proxy.invokeSuper(obj, args);
         System.out.println("after method run...");
         return result;
      ]}
  });
  SampleClass sample = (SampleClass) enhancer.create();
  sample.test();

end note
class Enhancer extends AbstractClassGenerator{
	- Class superclass
	- Callback[] callbacks
  + void setSuperclass(Class superclass)
  + void setCallback(Callback callback)
  + Object create()
  - Object createHelper()
  # void setNamePrefix(String namePrefix)
  # Object firstInstance(Class type)
  # Object nextInstance(Object instance)
}
abstract class AbstractClassGenerator implements ClassGenerator{
  # Object create(Object key)
  # abstract Object firstInstance(Class var1)
  # abstract Object nextInstance(Object var1)
}
interface ClassGenerator{
	+ generateClass(ClassVisitor var1)

}

Enhancer +-- Callback
interface Callback{}
interface MethodInterceptor extends Callback{
  + Object intercept(Object var1, Method var2, Object[] var3, MethodProxy var4)
}
Enhancer +-- Class
interface Class{}

interface Serializable{}

@enduml