如何在Spring 5 Xml中的WebContentInterceptor中设置cacheControlMappings

问题描述

我想为Spring MVC中的几个URL添加缓存控制指令（同时设置公共和最大使用时间），我想仅通过applicationContext.xml进行这些更改。

I want to add cache-control directive (set both public and max-age seconds) for a couple of URLs in Spring MVC and I want to do those changes via applicationContext.xml only.

我正在尝试设置 org.springframework.web.servlet.mvc.WebContentInterceptor 的地图属性 cacheControlMappings ，但是唯一的问题是没有属性设置方法的类的设计。解决方法是，我使用 org.springframework.beans.factory.config.MethodInvokingBean 调用 addCacheMapping 方法。

I am trying to set the map property cacheControlMappings of org.springframework.web.servlet.mvc.WebContentInterceptor, but the only problem is the design of the class which has no setter method for the property. As a workaround, I am invoking the addCacheMapping method using the org.springframework.beans.factory.config.MethodInvokingBean.

我在spring-mvc-config.xml中的配置如下-
我在创建 CacheControl bean如下，并且通过调试验证了此bean是否已成功创建，并已在应用程序上下文中填充了适当的值。

My configuration in spring-mvc-config.xml is as follows -I am creating a CacheControl bean as follows, and I verified by debugging that this bean gets created successfully with appropriate values populated in the application context.

<bean id="cacheControlFactory" class="org.springframework.http.CacheControl" factory-method="maxAge">
    <constructor-arg index="0" value="3600"/>
    <constructor-arg index="1">
        <value type="java.util.concurrent.TimeUnit">SECONDS</value>
    </constructor-arg>
</bean>

<bean id="myCacheControl" class="org.springframework.beans.factory.config.MethodInvokingFactoryBean">
    <property name="targetObject">
        <ref bean="cacheControlFactory"/>
    </property>
    <property name="targetMethod">
        <value>cachePublic</value>
    </property>
</bean>

然后我希望调用此方法- public void addCacheMapping（CacheControl cacheControl，String ... WebContentInterceptor 的路径），这会将条目添加到地图 cacheControlMappings 。

Then I wish to invoke this method - public void addCacheMapping(CacheControl cacheControl, String... paths) of WebContentInterceptor which will add entries to the map cacheControlMappings.

我验证了以编程方式调用此方法的效果很好，因此如果我从XML调用它，它应该可以正常工作吗？但是我正尝试这样做，如下所示，但这对我来说不起作用，并且我在最终地图中添加了零个条目。

I verified that calling this method programmatically works great, so it should work fine if I invoke it from the XML right? But I am trying to do the same, as shown below, but this does not work for me, and I get zero entries added to the final map.

<bean class="org.springframework.beans.factory.config.MethodInvokingBean">
    <property name="targetObject">
        <ref bean="webContentInterceptor"/>
    </property>
    <property name="targetMethod">
        <value>addCacheMapping</value>
    </property>
    <property name="arguments">
        <list>
            <ref bean="myCacheControl" />
            <value>/home</value>
            <value>/dp/**</value>
            <value>/**/b/*</value>
        </list>
    </property>
</bean>

为什么上述对 MethodInvokingBean 的调用不起作用？我是否以任何方式设置了错误的论点？可变参数是否需要其他处理？在服务器启动期间，我也看不到任何错误。

Why does the above invocation with MethodInvokingBean not work? Am I setting the arguments wrong in any way? Do the varargs need a different handling? I don't see any errors thrown either during server startup.

此外，我知道此SO线程（），其中所接受的答案提到XML本身无法执行此操作。我想通过尝试实施上述解决方案来再次确认这是否正确，但是它不起作用，但是我不明白为什么。

Also, I am aware of this SO thread (How to set Cache-control: private with applicationContext.xml in Spring 4.2 or later ) where the accepted answer mentions there is no way to do this in the XML itself. I wanted to re-confirm if that is correct by trying to implement above solution but it is not working, but I don't see why.

推荐答案

正如我所怀疑的那样，参数的填充方式存在问题。弹簧注入中的varargs必须作为一个显式列表而不是参数的重载给出（就像在Java中那样）。

As I had suspected, there was an issue in the way the arguments were getting populated. The varargs in a spring injection need to be given as an explicit list instead of an overload of arguments (like it's done in Java).

所以调用这种方法的正确方法-

So the correct way to invoke such a method -

public void addCacheMapping(CacheControl cacheControl, String... paths)

春季applicationContext.xml中的

如下-

in spring applicationContext.xml is as follows -

<bean class="org.springframework.beans.factory.config.MethodInvokingFactoryBean">
    <property name="targetObject">
        <ref bean="webContentInterceptor"/>
    </property>
    <property name="targetMethod">
        <value>addCacheMapping</value>
    </property>
    <property name="arguments">
        <list>
            <ref bean="myCacheControl" />
            <list>
                <value>/home</value>
                <value>/dp/**</value>
                <value>/**/b/*</value>
            </list>
        </list>
    </property>
</bean>

如您所见，我现在使用了 MethodInvokingFactoryBean 。 MethodInvokingBean 对我不起作用。

As you can see I have now used MethodInvokingFactoryBean. Somehow MethodInvokingBean did not work for me.

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