JSP 不显示来自 Spring 模型的对象 [英] JSPs not displaying objects from model in Spring
问题描述
我有一个应该很容易解决的问题，但我没有运气.
I have what should be an easy issue to solve, but I'm having no luck.
在我的 servlet-servlet.xml 文件中，我有以下 bean(除了其他 bean):
In my servlet-servlet.xml file, I have the following beans (in addition to others):
<bean id="viewResolver"
class="org.springframework.web.servlet.view.UrlBasedViewResolver">
<property name="viewClass" value="org.springframework.web.servlet.view.JstlView" />
<property name="prefix" value="/WEB-INF/jsp/" />
<property name="suffix" value=".jsp" />
</bean>
<context:component-scan base-package="com.servlet.web" />
我的测试控制器如下所示:
My test controller looks like this:
package com.servlet.web;
import java.util.Map;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.springframework.stereotype.Controller;
import org.springframework.ui.ModelMap;
import org.springframework.web.bind.annotation.RequestMapping;
@Controller
public class TestController
{
protected final Log log = LogFactory.getLog(getClass());
@RequestMapping("/test")
public String methodName(Map<String, Object> map) {
map.put("someMessage", "some string here");
return "test";
}
}
我的jsp视图是这样的:
My jsp view looks like this:
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN" "http://www.w3.org/TR/html4/strict.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en" lang="en">
<head>
<meta http-equiv="content-type" content="text/html; charset=utf-8" />
<title>servlet.com</title>
</head>
<body>
${someMessage}
</body>
</html>
所以，当我查看 jsp 时，我希望得到 someMessage 的值(这里是一些字符串)，但我只得到以下内容:
So, when I view the jsp, I'd expect the value of someMessage (some string here), but I only get the following:
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN" "http://www.w3.org/TR/html4/strict.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en" lang="en">
<head>
<meta http-equiv="content-type" content="text/html; charset=utf-8" />
<title>servlet.com</title>
</head>
<body>
${someMessage}
</body>
</html>
当我启动日志记录时，我看到我的 someMessage 对象被放置在模型中:
When I crank up the logging, I see that my someMessage object is being place in the model:
22:21:17,425 DEBUG DispatcherServlet:852 - DispatcherServlet with name 'servlet' determining Last-Modified value for [/servlet/access/test]
22:21:17,426 DEBUG DefaultAnnotationHandlerMapping:183 - Mapping [/test] to handler 'com.servlet.web.TestController@762fef'
22:21:17,426 DEBUG DispatcherServlet:868 - Last-Modified value for [/servlet/access/test] is: -1
22:21:17,426 DEBUG DispatcherServlet:700 - DispatcherServlet with name 'servlet' processing GET request for [/servlet/access/test]
22:21:17,427 DEBUG HandlerMethodInvoker:158 - Invoking request handler method: public java.lang.String com.servlet.web.TestController.methodName(java.util.Map)
22:21:17,427 DEBUG DispatcherServlet:1070 - Rendering view [org.springframework.web.servlet.view.JstlView: name 'test'; URL [/WEB-INF/jsp/test.jsp]] in DispatcherServlet with name 'servlet'
22:21:17,427 DEBUG JstlView:328 - Added model object 'someMessage' of type [java.lang.String] to request in view with name 'test'
22:21:17,428 DEBUG JstlView:237 - Forwarding to resource [/WEB-INF/jsp/test.jsp] in InternalResourceView 'test'
22:21:17,429 DEBUG DispatcherServlet:666 - Successfully completed request
显然，我的视图已正确映射，但我似乎无法访问添加到视图中请求的模型对象.过去我已经多次使用 Spring MVC 做过这种类型的事情，但我一定在这里遗漏了一些明显的东西.有任何想法吗?谢谢.
Obviously, my view is mapped correctly, but I can't seem to access model objects added to the request in the view. I've done this type of thing with Spring MVC many times in the past, but I must be missing something obvious here. Any ideas? Thanks.
推荐答案
您确定在您的 JSP 中启用了对 EL 的评估吗?我有时会遇到问题，它以某种方式被关闭.尝试评估像 ${'test'} 这样的简单表达式，看看是否出现了 'test'.
Are you sure that evaluation of EL is enabled in your JSP? I sometimes had the problem, that it got turned of somehow. Try evaluating a simple expression like ${'test'} and see if 'test' appears.
如果应该禁用 EL，您也可以尝试使用页面指令或其他内容启用它.
You can also try enabling it with page directives or something else if EL should be disabled.
<%@ page isScriptingEnabled="true" isELIgnored="false" %> //of course it has to be FALSE
(抱歉，我不记得这是否 100% 正确.它可能是 'isELEnabled')
(Sorry, I can't remember if this 100% correct. It might be 'isELEnabled')
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