将Spring的Proxy对象转换为实际的运行时类 [英] Casting a Spring's Proxy object to the actual runtime class

问题描述

我正在使用Spring，有时我想将对象强制转换为实际的运行时实现。

I'm using Spring, at one point I would like to cast the object to its actual runtime implementation.

示例：

Class MyClass extends NotMyClass {
    InterfaceA a;
    InterfaceA getA() { return a; }

    myMethod(SomeObject o) { ((ImplementationOfA) getA()).methodA(o.getProperty()); }
}

大喊 ClassCastException 因为 a 是一个 $ ProxyN 对象。虽然在beans.xml中我注入了一个类 ImplementationOfA 的bean。

That yells a ClassCastException since a is a $ProxyN object. Although in the beans.xml I injected a bean which is of the class ImplementationOfA .

编辑1
我扩展了一个类，我需要调用 ImplementationOfA中的方法。所以我想我需要施展。该方法会收到一个参数。

EDIT 1 I extended a class and I need to call for a method in ImplementationOfA. So I think I need to cast. The method receives a parameter.

编辑2

我最好扯掉它target class：

I better rip off the target class:

private T getTargetObject(Object proxy, Class targetClass) throws Exception {
    while( (AopUtils.isJdkDynamicProxy(proxy))) {
        return (T) getTargetObject(((Advised)proxy).getTargetSource().getTarget(), targetClass);
    }
    return (T) proxy; // expected to be cglib proxy then, which is simply a specialized class
}

I知道它不是很优雅但是很有效。

I know it is not very elegant but works.

所有学分 http://www.techper.net/2009/06/05/how-to-acess-target-object-behind-a-spring- proxy /
谢谢！

All credits to http://www.techper.net/2009/06/05/how-to-acess-target-object-behind-a-spring-proxy/ Thank you!

推荐答案

为什么需要演员？
关于 Spring代理使用情况这是一个很棒的文章，我建议你阅读，评论。

Why do you need to cast? About Spring proxy usage this is a great article, I suggest you to read it, comments as well.

以及 Spring AOP文档。

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