Servlet与JSP通讯的最佳实践 [英] Servlet to jsp communication best practice
问题描述
我正在学习如何在Google App Engine上编写Java Servlet和JSP页面.我正在尝试使用MVC模型，但不确定自己是否做对了.当前，我有一个servlet，在访问页面时会调用它. servlet完成所有处理，并创建一个HomePageViewModel对象，将其转发给jsp，如下所示:
I'm learning how to write java servlets and jsp pages on google app engine. I'm attempting to use an MVC model but I'm not sure if I'm doing it right. Currently, I have a servlet that is called when a page is accessed. The servlet does all the processing and creates a HomePageViewModel object that is forwarded to the jsp like this:
// Do processing here
// ...
HomePageViewModel viewModel = new HomePageViewModel();
req.setAttribute("viewModel", viewModel);
//Servlet JSP communication
RequestDispatcher reqDispatcher = getServletConfig().getServletContext().getRequestDispatcher("/jsp/home.jsp");
reqDispatcher.forward(req, resp);
在jsp方面，我有这样的东西:
Over on the jsp side, I have something like this:
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<%@ page import="viewmodels.HomePageViewModel" %>
<%
HomePageViewModel viewModel = (HomePageViewModel) request.getAttribute("viewModel");
pageContext.setAttribute("viewModel", viewModel);
%>
<html>
<body>
<% out.println(((HomePageViewModel)pageContext.getAttribute("viewModel")).Test); %>
</body>
</html>
所以我的问题有两个.首先，这是为小型Web应用程序做事的合理方法吗?这只是我上课的一个小项目.其次，在jsp文件中，是否有更好的方法来访问viewmodel数据?
So my question is two fold. First, is this a reasonable way to do things for a small webapp? This is just a small project for a class I'm taking. And second, in the jsp file, is there a better way to access the viewmodel data?
推荐答案
如果您遵守 Java规范(即，将私有属性与公共getter/setter一起使用)，
If you adhere the Javabeans spec (i.e. use private properties with public getters/setters),
public class HomePageViewModel {
private String test;
public String getTest() {
return test;
}
public void setTest(String test) {
this.test = test;
}
}
然后，您可以只使用EL(表达语言)来访问数据.
then you can just use EL (Expression Language) to access the data.
<%@ page pageEncoding="UTF-8" %>
<html>
<body>
${viewModel.test}
</body>
</html>
另请参见:
- 我们的Servlets Wiki页面
- 我们的JSP Wiki页面
- 我们的EL Wiki页面
- 如何避免JSP文件中的Java代码?
- Our Servlets wiki page
- Our JSP wiki page
- Our EL wiki page
- How to avoid Java code in JSP files?
See also:
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