Spring 3.0.6 MVC @PathVariable和@RequestParam在JSP视图中为空/空 [英] Spring 3.0.6 MVC @PathVariable and @RequestParam blank/empty in JSP view

问题描述

我一直在尝试建立一个非常简单的控制器/视图，但无法使其正常工作.在我的web.xml中，我定义了一个名为servlet-context.xml的<servlet>，它可以正常运行.在servlet-context.xml中，我设置了:

I have been trying to get an incredibly simple controller/view set up, and just can't make it work. In my web.xml, I've defined a <servlet> called servlet-context.xml, which is running ok. In servlet-context.xml, I've set:

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
    xmlns:mvc="http://www.springframework.org/schema/mvc"

<...other stuff in here... />

<mvc:annotation-driven />

还有其他事情.我的理解是，这就是使用@批注所需的全部内容.

among other things. My understanding is this is all that's needed to use @ annotations.

在我的控制器中，我有:

In my controller, I have:

@RequestMapping(value="/student/{username}/", method=RequestMethod.GET)
public String adminStudent(@PathVariable String username, @RequestParam String studentid) {
    return "student";
}

在我的student.jsp视图中，我有:

<p>This is the page where you would edit the stuff for ${username}.</p>
<p>The URL parameter <code>studentid</code> is set to ${studentid}.</p>

当我向http://localhost:8080/application/student/xyz123/?studentid=456发出请求时，得到了我期望的视图，但是所有变量均为空白或空:

When I make a request to http://localhost:8080/application/student/xyz123/?studentid=456, I get the view I expect, but all the variables are blank or null:

<p>This is the page where you would edit the stuff for .</p>
<p>The URL parameter <code>studentid</code> is set to .</p>

我怀疑web.xml或servlet-context.xml的设置方式存在问题，但我在任何地方都找不到罪魁祸首.据我所知，任何日志中都没有显示任何内容.

I suspect it's a problem with the way my web.xml or servlet-context.xml are set up, but I can't find the culprit anywhere. There's nothing showing up in any logs as far as I can see.

更新:我基于

...对我来说很好.我不明白为什么这个例子行得通，而我的行不通.是因为它们

...which works fine for me. I can't understand why this example works but mine doesn't. Is it because they're doing something different with servlet-context.xml?

<annotation-driven conversion-service="conversionService">
    <argument-resolvers>
        <beans:bean class="org.springframework.samples.mvc.data.custom.CustomArgumentResolver"/>
    </argument-resolvers>
</annotation-driven>

推荐答案

啊！终于找到答案了.

spring-mvc-showcase使用的是Spring 3.1，根据

The spring-mvc-showcase is using Spring 3.1, which will automatically expose @PathVariables to the model, according to SPR-7543.

如@duffymo和@JB Nizet所指出的那样，对于早于3.1的Spring版本，要使用model.put()添加到模型中.

As pointed out by @duffymo and @JB Nizet, adding to the Model with model.put() is the thing to do for versions of Spring earlier than 3.1.

Ted Young通过

Ted Young pointed me in the right direction with Spring: Expose @PathVariables To The Model.

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