Question

我想回显在Request中选择的缓存操作，以便它显示在浏览器上。我的JSP经验非常少。如何才能显示操作的值？

JSP：

<%@ taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c" %>

<html>
    <body>
        <h1>Cache Operation Results - ${operation}</h1>
        <ul>
            <c:forEach items="${results}" var="nextObject">
                <pre>${nextObject.toString()}</pre>
            </c:forEach>
        </ul>
    </body>
</html>

Controller snippet：

@RequestMapping(value = "/objectcache", method = RequestMethod.GET)
public ModelAndView objectCache(@RequestParam("operation") String operation, HttpServletRequest req) {

    List<String> cacheReturnValue = new ArrayList<String>();
    ModelAndView mav = new ModelAndView("/utils/objectCache", "results", cacheReturnValue);

    if (operation.equalsIgnoreCase("reload")) {
        cacheReturnValue = this.reloadCache();
    }

    mav.addObject("operation", operation);
    return new ModelAndView("/utils/objectCache", "results", cacheReturnValue);
}

Answer 1

JSP页面可以访问多个implicit objects via表达式。根据该文档中给出的示例，您可以获得如下参数值：

${param['operation']}

Answer 2

你有代码在删除错误后正常工作 - 你创建了ModelAndView两次，因此忽略了“operation”添加到第一个{{ 1}}对象。解决方案 - 只创建一次ModelAndView：

mav

修改

小提示：由于ModelAndView#addObject返回对@RequestMapping(value = "/objectcache", method = RequestMethod.GET) public ModelAndView objectCache(@RequestParam("operation") String operation, HttpServletRequest req) { List<String> cacheReturnValue = new ArrayList<String>(); if (operation.equalsIgnoreCase("reload")) { cacheReturnValue = this.reloadCache(); } ModelAndView mav = new ModelAndView("/utils/objectCache"); mav.addObject("results", cacheReturnValue); mav.addObject("operation", operation); return mav; }对象的引用，您可以链接它的调用而不创建像这样的变量this：

mav

Spring JSP - 如何显示请求值？

2 个答案: