Spring AOP的实现原理详解及实例

// JDK方式PersonService为接口，PersonServiceBean为实现类， 
 
 public class JDKProxyFactory implements InvocationHandler { 
  private Object targetObject; 
   
  public Object createProxyIntance(Object targetObject) 
  { 
  this.targetObject=targetObject; 
  return Proxy.newProxyInstance(this.targetObject.getClass().getClassLoader(),  
   this.targetObject.getClass().getInterfaces(), this); 
  } 
 
public Object invoke(Object proxy, Method method, Object[] args) 
 throws Throwable { 
  PersonServiceBean person=(PersonServiceBean)this.targetObject; 
  Object result=null; 
   if(person.getUser()!=null) 
   {  
   result = method.invoke(targetObject, args); 
   } 
  return result; 
} 
} 

//使用CGlib包实现PersonServiceBean为实现类，  而没有PersonService接口，      
 
public class CGlibProxyFactory implements MethodInterceptor{ 
 private Object targetObject; 
  
 public Object createProxyInstance(Object targetObject) 
 {  
  this.targetObject=targetObject; 
  Enhancer enhancer=new Enhancer(); 
  enhancer.setSuperclass(this.targetObject.getClass());//设置目标类的子类，该子类会覆盖所有父类中的非final方法 
  enhancer.setCallback(this);//设置回调 
 return enhancer.create(); 
 } 
 
public Object intercept(Object proxy, Method method, Object[] args, 
 MethodProxy methodProxy) throws Throwable { 
 PersonServiceBean person=(PersonServiceBean)this.targetObject; 
  Object result=null; 
   if(person.getUser()!=null) 
   {  
   result = methodProxy.invoke(targetObject, args); 
   } 
 return null; 
} 
}