<%@taglib uri="www.springframework.org/tags/form" prefix="form" %> <form:errors path="student1.*" /> 导致 "Unable to compile JSP page" 错误

Question

我正在尝试学习 Spring MVC，当尝试从互联网上获取示例时，我收到以下错误：

HTTP Status 500 - Unable to compile class for JSP

type Exception report

message Unable to compile class for JSP

description The server encountered an internal error that prevented it from fulfilling this request.

exception

org.apache.jasper.JasperException: Unable to compile class for JSP
    org.apache.jasper.JspCompilationContext.compile(JspCompilationContext.java:600)
    org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:363)
    org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:396)
    org.apache.jasper.servlet.JspServlet.service(JspServlet.java:340)
    javax.servlet.http.HttpServlet.service(HttpServlet.java:729)
    org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
    org.springframework.web.servlet.view.InternalResourceView.renderMergedOutputModel(InternalResourceView.java:168)
    org.springframework.web.servlet.view.AbstractView.render(AbstractView.java:303)
    org.springframework.web.servlet.DispatcherServlet.render(DispatcherServlet.java:1244)
    org.springframework.web.servlet.DispatcherServlet.processDispatchResult(DispatcherServlet.java:1027)
    org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:971)
    org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:893)
    org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:970)
    org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:861)
    javax.servlet.http.HttpServlet.service(HttpServlet.java:622)
    org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:846)
    javax.servlet.http.HttpServlet.service(HttpServlet.java:729)
    org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
root cause

java.lang.NullPointerException
    org.apache.tomcat.util.descriptor.tld.TldResourcePath.hashCode(TldResourcePath.java:164)
    java.util.HashMap.hash(HashMap.java:338)
    java.util.HashMap.get(HashMap.java:556)

这是我的 JSP 页面：

<%@taglib uri="www.springframework.org/tags/form" prefix="form" %>
<html>
<head>
<title>Admission Form</title>
</head>
<body>

<h1>${header_msg}</h1>
<h3>Admission Form for Engineering Courses</h3>

<form:errors path="student1.*" />
<form action="/Admissions/submitAdmissionForm.html" method="post">
    <table>
    <tr><td> Student's Name :   </td><td>   <input type="text" name="studentName" />    </td></tr>
    <tr><td> Student's Hobby :  </td><td>   <input type="text" name="studentHobby" />   </td></tr>
    <tr><td> Date of Birth :    </td><td>   <input type="text" name="studentDOB" />     </td></tr>
    <tr><td> Mobile No :        </td><td>   <input type="text" name="studentMobile" />  </td></tr>

    <tr><td> Skill set :        </td><td>   <select name="studentSkills" multiple>
                                            <option value="Core Java">Core Java</option>
                                            <option value="Spring Core">Spring Core</option>
                                            <option value="Spring MVC">Spring MVC</option>
                                            </select> </td></tr>
    </table>

    <table>
    <tr><td> Address :  </td></tr>
    <tr><td> Country:   <input type="text" name="studentAddress.country" />     </td>
        <td> City:      <input type="text" name="studentAddress.city" />        </td>
        <td> Street:    <input type="text" name="studentAddress.street" />      </td>
        <td> Pin code:  <input type="text" name="studentAddress.pincode" />     </td></tr>

    <tr><td> </td><td>  <input type="submit" value="Submit this form" />        </td></tr>
    </table>
</form>

</body>
</html>

我的控制器 class 包含以下代码：

@ModelAttribute
public void addingCommonObjects(ModelAndView model) {

    model.addObject("header_msg", "College of Engineering, Adoor");
}

@RequestMapping(value="/submitAdmissionForm.html", method=RequestMethod.POST)
public ModelAndView submitAdmissionForm(@ModelAttribute("student1") Student student, BindingResult result) {

    if(result.hasErrors()) {
        ModelAndView model = new ModelAndView("AdmissionForm");
        return model;
    }
    ModelAndView model = new ModelAndView("AdmissionFormSuccess");
    return model;
}

在控制器中添加 BindingResult 和在 JSP 页面中添加 <form:errors> 之前一切正常。当你们看到时，这可能是代码中的一个小问题，但在过去的 3-4 天里，我一直在努力找出这个问题。请提出建议。

Answer 1

<%@taglib uri="www.springframework.org/tags/form" prefix="form" %>

上一行中的

uri 不正确。uri 中缺少 http。试试下面

<%@taglib uri="http://www.springframework.org/tags/form" prefix="form" %>

<%@taglib uri="www.springframework.org/tags/form" prefix="form" %> <form:errors path="student1.*" /> 导致 "Unable to compile JSP page" 错误

<%@taglib uri="www.springframework.org/tags/form" prefix="form" %> <form:errors path="student1.*" /> causing "Unable to compile JSP page" error

forms

jsp

spring-mvc

error-handling

taglib