如何在JSP页面上迭代所有模型属性？

Question

我正在使用Spring 3.2.11.RELEASE和JBoss 7.1.3.Final和Java 6.我在控制器中使用了这个方法

@RequestMapping(value = "/method", method = RequestMethod.GET)
public String myMethod(final Model model,
                        final HttpServletRequest request,
                        final HttpServletResponse response,
                        final Principal principal) 

...
    model.addAttribute("paramName", "paramValue");

请注意我如何在模型中添加属性.我的问题是,在这个页面所服务的JSP页面上,我如何迭代模型中的所有属性并将它们输出为HIDDEN输入字段,其中INPUT的名称是属性名称,值是我插入的使用该属性的模型？

编辑:响应给出的答案,这是JSP解决方案的输出.请注意,那里没有模型属性.

        <input type='hidden' name='javax.servlet.jsp.jspRequest' value='org.springframework.web.context.support.ContextExposingHttpServletRequest@7a0a4c3f'>

        <input type='hidden' name='javax.servlet.jsp.jspPageContext' value='org.apache.jasper.runtime.PageContextImpl@3939794a'>

        <input type='hidden' name='appVersion' value='???application.version???'>

        <input type='hidden' name='javax.servlet.jsp.jspResponse' value='org.owasp.csrfguard.http.InterceptRedirectResponse@722033be'>

        <input type='hidden' name='javax.servlet.jsp.jspApplication' value='io.undertow.servlet.spec.ServletContextImpl@14c1252c'>

        <input type='hidden' name='org.apache.taglibs.standard.jsp.ImplicitObjects' value='javax.servlet.jsp.el.ImplicitObjectELResolver$ImplicitObjects@23c27a49'>

        <input type='hidden' name='javax.servlet.jsp.jspOut' value='org.apache.jasper.runtime.JspWriterImpl@b01a1ba'>

        <input type='hidden' name='javax.servlet.jsp.jspPage' value='org.apache.jsp.WEB_002dINF.views.lti.launch_jsp@1dcc48bf'>

        <input type='hidden' name='javax.servlet.jsp.jspConfig' value='io.undertow.servlet.spec.ServletConfigImpl@3fd40806'>

Answer 1

模型属性是“请求范围”对象，您可以执行以下操作（我使用 JSTL）：

    <c:forEach items="${requestScope}" var="par">
        <c:if test="${par.key.indexOf('attrName_') > -1}">
            <li>${par.key} - ${par.value}</li>
        </c:if>
    </c:forEach>

由于没有过滤器，您将拥有所有请求范围对象，因此我按我们想要检查的模型属性进行过滤

我使用这段代码进行了测试：

@RequestMapping(method = { RequestMethod.GET }, value = { "/*" })
    public String renderPage(Model model) throws Exception
    {
        String requestedUrl = req.getRequestURI();
        int indice = requestedUrl.lastIndexOf('/');
        String pagina = requestedUrl.substring(indice + 1);
        try
        {
            String usernameUtente = "default username utente";
            if (StringUtils.hasText(getPrincipal()))
            {
                usernameUtente = getPrincipal();
            }
            model.addAttribute("usernameUtente", usernameUtente);
            model.addAttribute("webDebug", webDebug);
            for(int i = 0; i<10; i++)
            {
                model.addAttribute("attrName_"+i, "attrValue_"+i);
            }
            return pagina;
        }
        catch (Exception e)
        {
            String message = "Errore nell'erogazione della pagina " + pagina;
            logger.error(message, e);
            return "genericError";
        }
    }

这就是我所看到的输出（我省略了不相关的打印，但请注意，您将打印所有请求范围对象：

attrName_0 - attrValue_0
attrName_1 - attrValue_1
attrName_2 - attrValue_2
attrName_3 - attrValue_3
attrName_4 - attrValue_4
attrName_5 - attrValue_5
attrName_6 - attrValue_6
attrName_7 - attrValue_7
attrName_8 - attrValue_8
attrName_9 - attrValue_9

我希望这可以帮助

安吉洛