问题描述
我是Spring MVC Framework的初学者.两天后我开始学习Spring.出于学习目的，我正在开发一个简单的应用程序.即从表单获取用户输入并在另一页中显示值.我得到了一个异常"java.lang.IllegalStateException:BeanResult'command'的BindingResult或普通目标对象都不能用作请求属性".我无法弄清楚代码中出了什么问题.我搜索了Google并尝试了许多解决方案，但问题仍然存在.
I am beginner to Spring MVC Framework. I started to learn Spring two days back. For learning purpose I am developing one simple Application. i.e., Get user input from form and display values in another page. I got an Exception " java.lang.IllegalStateException: Neither BindingResult nor plain target object for bean name 'command' available as request attribute". I cant figure out what's wrong in my code. I searched Google and tried many solution but the problem is still here.
这是我的看法index.jsp
Here is my viewindex.jsp
<form:form action="/addDisplay" method="POST">
<form:label path="name"><h3>Name</h3></form:label>
<form:input type="text" path="name" cssClass="form-control text-center" required="required"/>
<form:label path="age"><h3>Age</h3></form:label>
<form:input type="number" path="age" cssClass="form-control text-center" required="required"/>
<form:label path="work"><h3>Work Place</h3></form:label>
<form:input type="text" path="work" cssClass="form-control text-center" required="required"/>
<form:label path="designation"><h3>Designation</h3></form:label>
<form:input type="text" path="designation" cssClass="form-control text-center" required="required"/>
<form:label path="area"><h3>Area</h3></form:label>
<form:input type="text" path="area" placeholder="Where Are You From?" cssClass="form-control text-center" required="required"/>
<form:label path="mobile"><h3>Mobile Number</h3></form:label>
<form:input type="number" path="mobile" placeholder="Your Mobile Number.!" cssClass="form-control text-center" required="required"/>
<form:label path="email"><h3>Email</h3></form:label>
<form:input type="email" path="email" placeholder="Your Email Id..!" cssClass="form-control text-center" required="required"/>
<br/>
<input type="submit" value="Generate" class="btn btn-success form-control"/>
</form:form>
myself.jsp
myself.jsp
<div style="margin-top: 3%; font-size: 20px;">
<h3>My Introduction.</h3>
<p>
Hi, I am ${name} my age is ${age} and I am from ${area}. I am working as a ${designation}
in ${work}. You can contact me in my mobile ${mobile} and You can also shoot mail to
${email}.
</p>
</div>
web.xml
<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://java.sun.com/xml/ns/javaee" xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd" id="WebApp_ID" version="3.0">
<display-name>SpringWork</display-name>
<welcome-file-list>
<welcome-file>index.html</welcome-file>
<welcome-file>index.htm</welcome-file>
<welcome-file>index.jsp</welcome-file>
<welcome-file>default.html</welcome-file>
<welcome-file>default.htm</welcome-file>
<welcome-file>default.jsp</welcome-file>
</welcome-file-list>
<servlet>
<servlet-name>mvc-dispatcher</servlet-name>
<servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
<load-on-startup>1</load-on-startup>
</servlet>
<servlet-mapping>
<servlet-name>mvc-dispatcher</servlet-name>
<url-pattern>/</url-pattern>
</servlet-mapping>
<context-param>
<param-name>contextConfigLocation</param-name>
<param-value>/WEB-INF/mvc-dispatcher-servlet.xml</param-value>
</context-param>
<listener>
<listener-class>
org.springframework.web.context.ContextLoaderListener
</listener-class>
</listener>
</web-app>
mvc-dispatcher-servlet.xml
mvc-dispatcher-servlet.xml
<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:mvc="http://www.springframework.org/schema/mvc"
xmlns:context="http://www.springframework.org/schema/context"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="
http://www.springframework.org/schema/beans
http://www.springframework.org/schema/beans/spring-beans-3.0.xsd
http://www.springframework.org/schema/mvc
http://www.springframework.org/schema/mvc/spring-mvc-3.0.xsd
http://www.springframework.org/schema/context
http://www.springframework.org/schema/context/spring-context-3.0.xsd">
<context:component-scan base-package="com.infofaces.spring.form" />
<bean id="viewResolver" class="org.springframework.web.servlet.view.InternalResourceViewResolver">
<property name="prefix">
<value>/WEB-INF/pages/</value>
</property>
<property name="suffix">
<value>.jsp</value>
</property>
</bean>
<bean id="messageSource" class="org.springframework.context.support.ResourceBundleMessageSource">
<property name="basename" value="com/infofaces/spring/form/MySelf" />
</bean>
<mvc:resources mapping="/resources/**" location="/resources/" />
<mvc:annotation-driven />
</beans>
我的模型名称是Myself.java，它具有私有变量和该变量的getter，setter方法.这是我的控制器.
My model name is Myself.java and it has private variables and getter, setter methods for that variable. Here is my controller.
HelloController.java
HelloController.java
package com.infofaces.spring.form;
import org.springframework.stereotype.Controller;
import org.springframework.ui.ModelMap;
import org.springframework.web.bind.annotation.ModelAttribute;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.servlet.ModelAndView;
@Controller
public class HelloController {
@RequestMapping(value = "/display", method = RequestMethod.GET)
public ModelAndView display() {
return new ModelAndView("myself", "command", new MySelf());
}
@RequestMapping(value="/addDisplay", method = RequestMethod.POST)
public String addDisplay(@ModelAttribute("command") MySelf myself, ModelMap model) {
model.addAttribute("name",myself.getName());
model.addAttribute("age", myself.getAge());
model.addAttribute("work", myself.getWork());
model.addAttribute("designation", myself.getDesignation());
model.addAttribute("mobile", myself.getMobile());
model.addAttribute("email", myself.getEmail());
return "myself";
}
}
完整堆栈跟踪.
type Exception report
message java.lang.IllegalStateException: Neither BindingResult nor plain target object for bean name 'command' available as request attribute
description The server encountered an internal error that prevented it from fulfilling this request.
exception
org.apache.jasper.JasperException: java.lang.IllegalStateException: Neither BindingResult nor plain target object for bean name 'command' available as request attribute
org.apache.jasper.servlet.JspServletWrapper.handleJspException(JspServletWrapper.java:549)
org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:465)
org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:395)
org.apache.jasper.servlet.JspServlet.service(JspServlet.java:339)
javax.servlet.http.HttpServlet.service(HttpServlet.java:727)
org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
root cause
java.lang.IllegalStateException: Neither BindingResult nor plain target object for bean name 'command' available as request attribute
org.springframework.web.servlet.support.BindStatus.<init>(BindStatus.java:141)
org.springframework.web.servlet.tags.form.AbstractDataBoundFormElementTag.getBindStatus(AbstractDataBoundFormElementTag.java:179)
org.springframework.web.servlet.tags.form.AbstractDataBoundFormElementTag.getPropertyPath(AbstractDataBoundFormElementTag.java:199)
org.springframework.web.servlet.tags.form.LabelTag.autogenerateFor(LabelTag.java:130)
org.springframework.web.servlet.tags.form.LabelTag.resolveFor(LabelTag.java:120)
org.springframework.web.servlet.tags.form.LabelTag.writeTagContent(LabelTag.java:90)
org.springframework.web.servlet.tags.form.AbstractFormTag.doStartTagInternal(AbstractFormTag.java:103)
org.springframework.web.servlet.tags.RequestContextAwareTag.doStartTag(RequestContextAwareTag.java:80)
org.apache.jsp.index_jsp._jspx_meth_form_005flabel_005f0(index_jsp.java:265)
org.apache.jsp.index_jsp._jspx_meth_form_005fform_005f0(index_jsp.java:170)
org.apache.jsp.index_jsp._jspService(index_jsp.java:105)
org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:70)
javax.servlet.http.HttpServlet.service(HttpServlet.java:727)
org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:432)
org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:395)
org.apache.jasper.servlet.JspServlet.service(JspServlet.java:339)
javax.servlet.http.HttpServlet.service(HttpServlet.java:727)
org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
请帮助查找我的代码中的问题.预先感谢.
Please help to find problem in my code. Thanks in advance.
推荐答案
您在index.jsp文件中缺少commandName="command".
You are missing commandName="command" in your index.jsp file .
<form:form action="/addDisplay" method="POST" commandName="command" >
在处理index.jsp之前，请确保请求属性中的command对象可用.我希望这能奏效.
Make sure that command object is available in your request attribute before index.jsp is being processed. I hope this would work.
正如您在评论中说的那样，当您完全调用index.jsp时，会出现java.lang.IllegalStateException: Neither BindingResult nor plain target object for bean name 'command' available as request attribute错误.
EDIT : As you said in comment when you call index.jsp definatily you will get java.lang.IllegalStateException: Neither BindingResult nor plain target object for bean name 'command' available as request attribute error.
因为正在呈现您的jsp命令对象时，首先您必须向控制器发出请求，将对象放入模型名称中command，然后提供视图名称index.jsp
Because when your jsp is being rendered command object not available for that first you have to make request to controller , put object into Model name it command and then provide view name index.jsp
例如:
@RequestMapping(value = "/index", method = RequestMethod.GET)
public ModelAndView display() {
return new ModelAndView("index", "command", new MySelf());
}
现在您将不会收到该错误.我希望这能奏效.
Now you won't get that error. I hope this would work.
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