如何在 Spring.NET 中使用 DefaultAdvisorAutoProxyCreator 定义线程范围的对象 [英] How to Define Thread-scoped objects with DefaultAdvisorAutoProxyCreator in Spring.NET

问题描述

我想使用 DefaultAdvisorAutoProxyCreator 创建一个线程本地对象(带有拦截器).我知道如何使用 ProxyFactoryObject 做到这一点:

I want to create a thread-local object (with interceptors) using DefaultAdvisorAutoProxyCreator. I know how to do that using ProxyFactoryObject:

<?xml version="1.0" encoding="utf-8"?>
<objects xmlns="http://www.springframework.net">
    <object id="ConsoleLoggingBeforeAdvisor" type="Spring.Aop.Support.DefaultPointcutAdvisor" singleton="false">
        <property name="Advice">
            <object type="Spring.Examples.AopQuickStart.ConsoleLoggingBeforeAdvice"/>
        </property>
    </object>
    <object id="ServiceCommandTargetSource" type="Spring.Aop.Target.ThreadLocalTargetSource">
        <property name="TargetObjectName" value="ServiceCommandTarget"/>
   </object>
    <object id="ServiceCommandTarget" type="Spring.Examples.AopQuickStart.ServiceCommand" singleton="false"/>
    <object name="ServiceCommand" type="Spring.Aop.Framework.ProxyFactoryObject">
        <property name="TargetSource" ref="ServiceCommandTargetSource"/>
        <property name="InterceptorNames">
            <list>
                <value>ConsoleLoggingBeforeAdvisor</value>
            </list>
        </property>
    </object>
</objects>

但是，我不知道如何使用 DefaultAdvisorAopCreator 获得相同的效果.这是我尝试过的(但没有用):

However, I don't know how to get the same effect using DefaultAdvisorAopCreator. Here's what I tried (but didn't work):

<?xml version="1.0" encoding="utf-8"?>
<objects xmlns="http://www.springframework.net">
    <object id="ConsoleLoggingBeforeAdvisor" type="Spring.Aop.Support.DefaultPointcutAdvisor" singleton="false">
        <property name="Advice">
            <object type="Spring.Examples.AopQuickStart.ConsoleLoggingBeforeAdvice"/>
        </property>
    </object>
    <object id="ServiceCommand" type="Spring.Examples.AopQuickStart.ServiceCommand" singleton="false"/>
    <object type="Spring.Aop.Framework.AutoProxy.DefaultAdvisorAutoProxyCreator">
        <property name="CustomTargetSourceCreators">
            <list element-type="Spring.Aop.Framework.AutoProxy.ITargetSourceCreator">
                <object id="ThreadLocalTargetSourceCreator" type="Spring.Examples.AopQuickStart.ThreadLocalTargetSourceCreator"/>
            </list>
        </property>
    </object>
</objects>

ThreadLocalTargetSourceCreator 是一个自定义类，它无条件返回一个 ThreadLocalTargetSource 实例:

ThreadLocalTargetSourceCreator is a custom class that unconditionally returns a ThreadLocalTargetSource instance:

namespace Spring.Examples.AopQuickStart {
    public class ThreadLocalTargetSourceCreator : AbstractPrototypeTargetSourceCreator {
        protected override AbstractPrototypeTargetSource CreatePrototypeTargetSource(Type objectType, string name, IObjectFactory factory) {
            return new ThreadLocalTargetSource();
        }
    }
}

所以，总而言之，当我使用第一个配置(使用 ProxyFactoryObject)从 Spring.NET 请求 ServiceCommand 时，我只得到每个线程的一个对象实例(正确的行为).但是，使用第二个配置 (DefaultAdvisorAutoProxyCreator)，我每次都会得到一个新实例(错误的行为；每个线程期望一个实例).

So, in summary, when I request ServiceCommand from Spring.NET with the first config (using ProxyFactoryObject), I get only one instance of the object per thread (correct behavior). However, with the second config (DefaultAdvisorAutoProxyCreator), I get a new instance every time (incorrect behavior; expecting one instance per thread).

有什么想法吗?

推荐答案

好的，我找到了它没有按预期工作的原因.看起来很愚蠢，我正在从 AbstractPrototypeTargetSourceCreator.GetTargetSource() 创建并返回 ThreadLocalTargetSource 的新实例.当然，ThreadLocalTargetSource 的每个新实例都不知道它的堂兄弟"之前创建的任何现有目标实例，因此每次请求实例时它都会创建其目标的新实例.

Ok, I found out why it was not working as expected. Silly as it seems, I was creating and returning a new instance of ThreadLocalTargetSource from AbstractPrototypeTargetSourceCreator.GetTargetSource(). Of course, each new instance of ThreadLocalTargetSource would have no clue of any existing target instances created by its "cousins" before, so it would create a new instance of its target every time an instance was requested.

解决方法很简单.我刚刚更新了 ITargetSourceCreator 的实现，以确保它创建了 ThreadLocalTargetSource 的单个实例并在每次调用 AbstractPrototypeTargetSourceCreator.GetTargetSource() 时返回该实例:

The resolution was very simple. I just updated my implementation of ITargetSourceCreator to make sure it created a single instance of ThreadLocalTargetSource and returned that instance each time AbstractPrototypeTargetSourceCreator.GetTargetSource() was called:

namespace Spring.Examples.AopQuickStart {
    public class ThreadLocalTargetSourceCreator : AbstractPrototypeTargetSourceCreator {
        private readonly ThreadLocalTargetSource _threadLocalTargetSource;

        public ThreadLocalTargetSourceCreator() {
            _threadLocalTargetSource = new ThreadLocalTargetSource();
        }

        protected override AbstractPrototypeTargetSource CreatePrototypeTargetSource(Type objectType, string name, IObjectFactory factory) {
            return _threadLocalTargetSource;
        }
    }
}

使用此代码，它非常适合我，并且我的代理对象获得了线程本地生命周期.

With this code, it works perfectly for me and I get a thread-local life time for my proxied objects.

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