我想通过扩展类 BodyTagSupport 从标签处理程序中在自定义标签名称 Simple 中显示 JSP 的正文值，但得到运行时异常；o)
JSP 代码是:
<html><body>
<%@ taglib prefix="mine" uri="simpleTags" %>
Advisor page
<mine:simple>
Balle Balle
</mine:simple>
</html></body>
标签处理类是:
package foo;
import java.io.*;
import javax.servlet.jsp.*;
import javax.servlet.jsp.tagext.*;
public class SelectTagHandler extends BodyTagSupport
{
public int doStartTag() throws JspException{
return EVAL_BODY_BUFFERED;
}
public int EndTag()
{
try{
pageContext.getOut().print(bodyContent);
}
catch(Exception e)
{
}
return EVAL_PAGE;
}
我得到的异常是:
type Exception report
message
description The server encountered an internal error () that prevented it from fulfilling this request.
exception
org.apache.jasper.JasperException: foo.SelectTagHandler.setJspContext(Ljavax/servlet/jsp/JspContext;)V
org.apache.jasper.servlet.JspServletWrapper.handleJspException(JspServletWrapper.java:460)
org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:355)
org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:329)
org.apache.jasper.servlet.JspServlet.service(JspServlet.java:265)
javax.servlet.http.HttpServlet.service(HttpServlet.java:729)
root cause
javax.servlet.ServletException: foo.SelectTagHandler.setJspContext(Ljavax/servlet/jsp/JspContext;)V
org.apache.jasper.runtime.PageContextImpl.doHandlePageException(PageContextImpl.java:841)
org.apache.jasper.runtime.PageContextImpl.handlePageException(PageContextImpl.java:774)
org.apache.jsp.new_jsp._jspService(new_jsp.java:60)
org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:98)
javax.servlet.http.HttpServlet.service(HttpServlet.java:729)
org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:331)
org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:329)
org.apache.jasper.servlet.JspServlet.service(JspServlet.java:265)
javax.servlet.http.HttpServlet.service(HttpServlet.java:729)
root cause
java.lang.NoSuchMethodError: foo.SelectTagHandler.setJspContext(Ljavax/servlet/jsp/JspContext;)V
org.apache.jsp.new_jsp._jspx_meth_mine_005fsimple_005f0(new_jsp.java:73)
org.apache.jsp.new_jsp._jspService(new_jsp.java:51)
org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:98)
javax.servlet.http.HttpServlet.service(HttpServlet.java:729)
org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:331)
org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:329)
org.apache.jasper.servlet.JspServlet.service(JspServlet.java:265)
javax.servlet.http.HttpServlet.service(HttpServlet.java:729)
note The full stack trace of the root cause is available in the Apache Tomcat/5.5.27 logs.
编辑:我的 TLD 文件的代码是:
<taglib xmlns="http://java.sun.com/xml/ns/j2ee"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://java.sun.com/xml/ns/j2ee/web-jsptaglibrary_2_0.xsd" version="2.0">
<tlib-version>1.2</tlib-version>
<uri>simpleTags</uri>
<tag>
<name>simple</name>
<tag-class>foo.SelectTagHandler</tag-class>
<body-content>scriptless</body-content>
</tag>
</taglib>
我在这里做错了什么？
最佳答案
setJspContext 只适用于SimpleTag 和SimpleTagSupport，不适用于BodyTag(不要问我为什么)。出于某种原因，Tomcat 将您的标签视为 SimpleTag。问题可能出在您的 TLD 文件中，您可以修改您的问题以添加它吗？
关于java - 运行经典标签处理程序时出现问题，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/1181622/