解决JSP中拼装数据为XML出现的问题

 一、应用背景

JSP取得Servlet中放入request的List，将List中的数据拼装成XML。以下代码在Eclipse的内置浏览器中显示为xml，没有问题。

[java]
/**
* 新闻Servlet
* @author 徐越
*
*/
public class ListServlet extends HttpServlet
{
private static final long serialVersionUID = 1L;
private VideoNewsService vs = new VideoNewsServiceImpl();

protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException
{
doPost(request, response);
}

protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException
{
List<VideoNews> news = vs.readNews();
request.setAttribute("lstnews", news);
request.getRequestDispatcher("/WEB-INF/pages/news.jsp").forward(request, response);
}
}

/**
* 新闻Servlet
* @author 徐越
*
*/
public class ListServlet extends HttpServlet
{
private static final long serialVersionUID = 1L;
private VideoNewsService vs = new VideoNewsServiceImpl();

protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException
{
doPost(request, response);
}

protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException
{
List<VideoNews> news = vs.readNews();
request.setAttribute("lstnews", news);
request.getRequestDispatcher("/WEB-INF/pages/news.jsp").forward(request, response);
}
}
[html]
<%@ page language="java" contentType="text/xml; charset=utf-8" pageEncoding="utf-8"%>
<%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %>
<?xml version="1.0" encoding="UTF-8"?>
<videoNews>
<c:forEach items="${lstnews}" var="n">
<news id="${n.id }">
<title>${n.title }</title>
<length>${n.timeLength }</length>
</news>
</c:forEach>
</videoNews>

<%@ page language="java" contentType="text/xml; charset=utf-8" pageEncoding="utf-8"%>
<%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %>
<?xml version="1.0" encoding="UTF-8"?>

<videoNews>
<c:forEach items="${lstnews}" var="n">
<news id="${n.id }">
<title>${n.title }</title>
<length>${n.timeLength }</length>
</news>
</c:forEach>
</videoNews>

二、发现问题

火狐中报错：XML解析错误：XML 或文本声明不在实体的开头

chrome报错：XML declaration allowed only at the start of the document

根据错误信息，可以知道XML声明<?xml version="1.0" encoding="UTF-8"?>必须在文档的开头。

三、解决问题

将page、taglib、xml同时放在第一行即可，一个接一个的后面。虽然不好看，但是解决问题哦