通过属性或主体将XML文档传递给JSP自定义标记 [英] Pass XML document via attribute or body to JSP custom tag

问题描述

我想知道是否可以将xml文档传递给纯 jstl定义的JSP自定义标记，如下所示：
自定义标记的主体，例如：

 < mt：mytag> 
< people> 
< person name =bobage =23/> 
< person name =sueage =45/> 
< person name =moeage =35/> 
< / people> 
< mt：mytag> 
  

或作为标签的属性，如下所示：

 < mt：mytag message =http：//link.to.document.xml/> 
  

这是标签本身

 <％@ tag description =xml parserpageEncoding =UTF-8％> 
<％@ taglib uri =http://java.sun.com/jsp/jstl/coreprefix =c％> 
<％@ taglib uri =http://java.sun.com/jsp/jstl/xmlprefix =x％> 
<％@ attribute name =message％> OR< jsp：doBody var =message/> 
< x：parse var =adoc =$ {message}/> 
< x：forEach var =currentselect =$ a / people / person> 
< ul> 
< li> 
名称< x：out select =$ current / @ name/>年龄< x：out select =$ current / @ age/> 
< / li> 
< / ul> 
< / x：forEach> 
  

可以在jsp页面内处理带有jstl的xml，基本上是在forEach之后复制代码并在jsp中粘贴。它甚至可以在页面请求中将xml作为POST / GET参数获取并在页面中处理它。

否则，在执行上述示例时，有各种各样的这种错误：

  PWC6197：jsp文件中第9行：9位错误：/ WEB-INF / tags / test2.tag 
 PWC6199：生成的servlet错误：
无法访问javax.servlet.jsp.jstl.core.LoopTagSupport 
找不到javax.servlet.jsp.jstl.core.LoopTagSupport的类文件
 
 PWC6197：jsp文件中的行：9发生错误：/ WEB-INF/tags/test2.tag 
 PWC6199：生成的servlet错误：
找不到符号
 symbol：方法setPageContext（javax.servlet.jsp.PageContext）
 location：变量_jspx_th_x_forEach_0 ....... 
  

请注意，完全可以处理非纯JSTL（使用java代码）中的正文内容或属性链接，只是想知道JSTL + EL是否有这样的功能。 / p>

编辑：分辨率

看起来Netbeans IDE有 bug ，默认情况下它不会添加JSTL库。您可以通过库 - >添加库 - >导入 - > Jstl 1.1->添加库来修复它

解决方案

这样可以。

 <％@ taglib tagdir =/ WEB-INF / tagsprefix =mt％> 
<％@ taglib uri =http://java.sun.com/jsp/jstl/coreprefix =c％> 
<％@ taglib uri =http://java.sun.com/jsp/jstl/xmlprefix =x％> 
< c：set var =message> 
< people> 
< person name =bobage =23/> 
< person name =sueage =45/> 
< person name =moeage =35/> 
< / people> 
< / c：set> 
< mt：mytag message =$ {message}/> 
  

实际上，你的第一个代码块（使用正文）也适用于我。
如果您想使用文件，请使用以下内容。

 <％@ taglib tagdir =/ WEB-INF / tagsprefix =mt％> 
< mt：mytag messageUrl =http：//link.to.document.xml/> 
  

和标签文件;

 <％@ tag description =xml parserpageEncoding =UTF-8％> 
<％@ taglib uri =http://java.sun.com/jsp/jstl/coreprefix =c％> 
<％@ taglib uri =http://java.sun.com/jsp/jstl/xmlprefix =x％> 
<％@ attribute name =messageUrl％> 
< c：import url =$ {messageUrl}var =message/> 
< x：parse var =adoc =$ {message}/> 
< x：forEach var =currentselect =$ a / people / person> 
< ul> 
< li> 
名称< x：out select =$ current / @ name/>年龄< x：out select =$ current / @ age/> 
< / li> 
< / ul> 
< / x：forEach> 
  

关于您的错误消息，请告诉我们您使用的是哪个Web服务器。还要告诉我们您下载了哪些JSTL罐子以及从哪里下载。

I wonder if it's possible to pass an xml document to a pure jstl-defined JSP custom tag either as: the body of the custom tag, such as:

<mt:mytag>
    <people>
        <person name="bob" age="23" />
        <person name="sue" age="45" />
        <person name="moe" age="35" />
    </people>
<mt:mytag>

or as an attribute of the tag like this:

<mt:mytag message="http://link.to.document.xml" />

This is the tag itself

<%@tag description="xml parser" pageEncoding="UTF-8"%>
<%@ taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c"%>
<%@ taglib uri="http://java.sun.com/jsp/jstl/xml" prefix="x" %>
<%@attribute name="message"%> OR <jsp:doBody var="message" />
<x:parse var="a" doc="${message}" />
<x:forEach var="current" select="$a/people/person">
    <ul>
        <li>
            Name <x:out select="$current/@name" /> age <x:out select="$current/@age" />
        </li>
    </ul>
</x:forEach>

It is possible to process an xml with jstl from inside a jsp page, basically copying the code after forEach and pasting in the jsp. It works even to get the xml as a POST/GET parameter in the page request and process it in the page.

Otherwise, when doing the above examples, there are various errors of this kind:

PWC6197: An error occurred at line: 9 in the jsp file: /WEB-INF/tags/test2.tag
PWC6199: Generated servlet error:
cannot access javax.servlet.jsp.jstl.core.LoopTagSupport
class file for javax.servlet.jsp.jstl.core.LoopTagSupport not found

PWC6197: An error occurred at line: 9 in the jsp file: /WEB-INF/tags/test2.tag
PWC6199: Generated servlet error:
cannot find symbol
symbol:   method setPageContext(javax.servlet.jsp.PageContext)
location: variable _jspx_th_x_forEach_0 of .......

Please note that it's perfectly possible to process either the body content or an attribute link inside a non-pure JSTL (with java code), just wondering if JSTL+EL had such facilities.

Edit: Resolution

Looks like the Netbeans IDE has a bug where it does not add the JSTL libraries by default. You fix it by Libraries->Add Library->Import->Jstl 1.1->Add Library

解决方案

This works.

<%@ taglib tagdir="/WEB-INF/tags" prefix="mt" %>
<%@ taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c"%>
<%@ taglib uri="http://java.sun.com/jsp/jstl/xml" prefix="x" %>
<c:set var="message">
    <people>
        <person name="bob" age="23" />
        <person name="sue" age="45" />
        <person name="moe" age="35" />
    </people>
</c:set>
<mt:mytag message="${message}" />

Actually, your first code block(using body) works for me as well. If you want to use a file, then use the following.

<%@ taglib tagdir="/WEB-INF/tags" prefix="mt" %>
<mt:mytag messageUrl="http://link.to.document.xml" />

and tag file;

<%@tag description="xml parser" pageEncoding="UTF-8"%>
<%@ taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c"%>
<%@ taglib uri="http://java.sun.com/jsp/jstl/xml" prefix="x" %>
<%@attribute name="messageUrl"%>
<c:import url="${messageUrl}" var="message" />
<x:parse var="a" doc="${message}" />
<x:forEach var="current" select="$a/people/person">
    <ul>
        <li>
            Name <x:out select="$current/@name" /> age <x:out select="$current/@age" />
        </li>
    </ul>
</x:forEach>

In regard to your error messages, please tell us which web server you are using. Also tell us which JSTL jars you downloaded and from where.

这篇关于通过属性或主体将XML文档传递给JSP自定义标记的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！