spring - Bean 名称的 BindingResult 和普通目标对象都不是

Question

我是 Spring 框架的新手。我正在做一个关于 Spring 3 MVC 的教程，运行 web 时出现异常。

例外：

java.lang.IllegalStateException: Neither BindingResult nor plain target object for bean name 'contact1' available as request attribute
org.springframework.web.servlet.support.BindStatus.<init>(BindStatus.java:141)
org.springframework.web.servlet.tags.form.AbstractDataBoundFormElementTag.getBindStatus(AbstractDataBoundFormElementTag.java:174)
org.springframework.web.servlet.tags.form.AbstractDataBoundFormElementTag.getPropertyPath(AbstractDataBoundFormElementTag.java:194)
org.springframework.web.servlet.tags.form.LabelTag.autogenerateFor(LabelTag.java:129)
org.springframework.web.servlet.tags.form.LabelTag.resolveFor(LabelTag.java:119)
org.springframework.web.servlet.tags.form.LabelTag.writeTagContent(LabelTag.java:89)
org.springframework.web.servlet.tags.form.AbstractFormTag.doStartTagInternal(AbstractFormTag.java:102)
org.springframework.web.servlet.tags.RequestContextAwareTag.doStartTag(RequestContextAwareTag.java:79)
org.apache.jsp.contact_jsp._jspx_meth_form_005flabel_005f0(contact_jsp.java:222)
org.apache.jsp.contact_jsp._jspx_meth_form_005fform_005f0(contact_jsp.java:144)
org.apache.jsp.contact_jsp._jspService(contact_jsp.java:93)
org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:70)
javax.servlet.http.HttpServlet.service(HttpServlet.java:722)
org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:432)
org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:390)
org.apache.jasper.servlet.JspServlet.service(JspServlet.java:334)
javax.servlet.http.HttpServlet.service(HttpServlet.java:722)

联系人控制器.java

@Controller
@RequestMapping("/contact.jsp")
public class ContactController {

@Autowired
private ContactService contactService;

@RequestMapping(method=RequestMethod.GET)
public String showForm(ModelMap model) {
    model.addAttribute("contact1", new Contact());
    //map.put("contactList", contactService.listContact());

    //return new ModelAndView("/contact","contact", new Contact());
    return "contact";

}

@RequestMapping(value = "/add", method = RequestMethod.POST)
public String addContact(@ModelAttribute("contact")
Contact contact, BindingResult result) {

    contactService.addContact(contact);

    return "redirect:/contact";
}

@RequestMapping("/delete/{contactId}")
public String deleteContact(@PathVariable("contactId")
Integer contactId) {

    contactService.removeContact(contactId);

    return "redirect:/index";
}
}

索引.jsp

<?xml version="1.0" encoding="ISO-8859-1"?>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
</head>
<body>
    <jsp:forward page="contact.jsp" ></jsp:forward>
</body>

联系人.jsp

<%@taglib uri="http://www.springframework.org/tags" prefix="spring"%>
    <%@taglib uri="http://www.springframework.org/tags/form" prefix="form"%>
    <%@taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c"%>
    <html>
    <head>
    <title>Spring 3 MVC Series - Contact Manager | viralpatel.net</title>
    </head>
    <body>

<h2>Contact Manager</h2>

<form:form action="/contact.jsp" method="POST" modelAttribute="contact1">

    <table>
        <tr>
            <td><form:label path="firstname">
                    <spring:message code="label.firstname" />
                </form:label></td>
            <td><form:input path="firstname" /></td>
        </tr>
        <tr>
            <td><form:label path="lastname">
                    <spring:message code="label.lastname" />
                </form:label></td>
            <td><form:input path="lastname" /></td>
        </tr>
        <tr>
            <td><form:label path="email">
                    <spring:message code="label.email" />
                </form:label></td>
            <td><form:input path="email" /></td>
        </tr>
        <tr>
            <td><form:label path="telephone">
                    <spring:message code="label.telephone" />
                </form:label></td>
            <td><form:input path="telephone" /></td>
        </tr>
        <tr>
            <td colspan="2"><input type="submit"
                value="<spring:message code="label.addcontact"/>" /></td>
        </tr>
    </table>
</form:form>


<h3>Contacts</h3>
<c:if test="${!empty contactList}">
    <table class="data">
        <tr>
            <th>Name</th>
            <th>Email</th>
            <th>Telephone</th>
            <th>&nbsp;</th>
        </tr>
        <c:forEach items="${contactList}" var="contact">
            <tr>
                <td>${contact.lastname}, ${contact.firstname}</td>
                <td>${contact.email}</td>
                <td>${contact.telephone}</td>
                <td><a href="delete/${contact.id}">delete</a></td>
            </tr>
        </c:forEach>
    </table>
</c:if>

springapp-servlet.xml

<?xml  version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"   xmlns:aop="http://www.springframework.org/schema/aop"
xmlns:context="http://www.springframework.org/schema/context"
xmlns:jee="http://www.springframework.org/schema/jee" xmlns:lang="http://www.springframework.org/schema/lang"
xmlns:p="http://www.springframework.org/schema/p" xmlns:tx="http://www.springframework.org/schema/tx"
xmlns:util="http://www.springframework.org/schema/util"
xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd
    http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop.xsd
    http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context.xsd
    http://www.springframework.org/schema/jee http://www.springframework.org/schema/jee/spring-jee.xsd
    http://www.springframework.org/schema/lang http://www.springframework.org/schema/lang/spring-lang.xsd
    http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx.xsd
    http://www.springframework.org/schema/util http://www.springframework.org/schema/util/spring-util.xsd">

<context:annotation-config />

<!-- Scan all java class -->
<context:component-scan base-package="*" />


<bean id="jspViewResolver"
    class="org.springframework.web.servlet.view.InternalResourceViewResolver">
    <property name="viewClass"
        value="org.springframework.web.servlet.view.JstlView" />
    <property name="prefix" value="/WEB-INF/" />
    <property name="suffix" value=".jsp" />
</bean>

<bean id="simpleUrlMapping"
    class="org.springframework.web.servlet.handler.SimpleUrlHandlerMapping">
    <property name="mappings">
        <props>
            <prop key="/contact.jsp">contact</prop>
        </props>
    </property>
</bean>

<bean id="contact" name="contact" class="controller.ContactController" />

<!--    Declare DAO and Service refer to DAOImpl and ServiceImpl -->
<bean name="contactService" class="service.ContactServiceImpl"
    autowire="constructor" />
<bean name="contactDAO" class="dao.ContactDAOImpl" autowire="constructor" />


<bean id="messageSource"
    class="org.springframework.context.support.ReloadableResourceBundleMessageSource">
    <property name="basename" value="classpath:messages" />
    <property name="defaultEncoding" value="UTF-8" />
</bean>
<bean id="propertyConfigurer"
    class="org.springframework.beans.factory.config.PropertyPlaceholderConfigurer"
    p:location="/WEB-INF/jdbc.properties" />

<bean id="dataSource" class="org.apache.commons.dbcp.BasicDataSource"
    destroy-method="close" p:driverClassName="${jdbc.driverClassName}"
    p:url="${jdbc.databaseurl}" p:username="${jdbc.username}" p:password="${jdbc.password}" />


<bean id="sessionFactory"
    class="org.springframework.orm.hibernate3.LocalSessionFactoryBean">
    <property name="dataSource" ref="dataSource" />
    <property name="configLocation">
        <value>classpath:hibernate.cfg.xml</value>
    </property>
    <property name="configurationClass">
        <value>org.hibernate.cfg.AnnotationConfiguration</value>
    </property>
    <property name="hibernateProperties">
        <props>
            <prop key="hibernate.dialect">${jdbc.dialect}</prop>
            <prop key="hibernate.show_sql">true</prop>
        </props>
    </property>
</bean>

<tx:annotation-driven />
<bean id="transactionManager"
    class="org.springframework.orm.hibernate3.HibernateTransactionManager">
    <property name="sessionFactory" ref="sessionFactory" />
</bean>

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"
xmlns:web="http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd"
xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd"
id="WebApp_ID" version="2.5">
<welcome-file-list>
    <welcome-file>index.jsp</welcome-file>
</welcome-file-list>

<servlet>
    <servlet-name>springapp</servlet-name>
    <servlet-class>
        org.springframework.web.servlet.DispatcherServlet
    </servlet-class>
    <load-on-startup>1</load-on-startup>
</servlet>

<servlet-mapping>
    <servlet-name>springapp</servlet-name>
    <url-pattern>/</url-pattern>
</servlet-mapping>

<context-param>
    <param-name>contextConfigLocation</param-name>
    <param-value>/WEB-INF/springapp-servlet.xml</param-value>
</context-param>

<listener>
    <listener-class>
           org.springframework.web.context.ContextLoaderListener
     </listener-class>
</listener>

请帮我解决这个问题。我知道问题发生是因为 jsp 页面找不到 modelAttribue 但我不知道如何解决它。

谢谢

score 1 · Accepted Answer

请提供您的 web.xml 条目，它实际上映射了 Dispacher-servlet。我知道您的问题是什么，但根据该映射，我可以建议您进行确切的更改。我复制了您的代码并进行了一些更改，现在模型已绑定。你能看看这个吗？

你的jsp

<form:form action="/web/contact.jsp/add" method="POST" commandName="contact1">

web.xml 映射是

<servlet>
    <servlet-name>springapp</servlet-name>
    <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
    <load-on-startup>1</load-on-startup>
</servlet>

<servlet-mapping>
    <servlet-name>springapp</servlet-name>
    <url-pattern>/web/*</url-pattern>
</servlet-mapping>

我正在调用这个 url 来访问表单 /web/contact.jsp。这将调用 GET 方法并提供空白表单，绑定命令类名称="contact1"。

score 1 · Accepted Answer

这意味着从控制器传递的模型不包含名为的属性contact1。添加

model.addAttribute("contact1", new Contact());

到返回此视图的控制器。
Dispatcher servlet 获取每个模型属性并将它们作为请求属性传递给视图。由于您contact1在模型中缺少，因此它给出的错误为

 Neither BindingResult nor plain target object for bean name 'contact1' available as request attribute

并检查您的控制器映射。调试您的应用程序并检查控制器是否被调用并contact1成功添加到模型中。

编辑：

您同时使用两者commandName，modelAttribute最终达到相同的目的。删除commandName并仅使用moedlAttribute，因为ModelAttribute取代CommandAttribute.
检查链接以获取更多详细信息http://chompingatbits.com/2009/08/25/spring-formtag-commandname-vs-modelattribute/

score 0 · Accepted Answer

在调试模式下运行您的应用程序。检查您的控制器是否调用方法

public String showForm(ModelMap model) {}.

当您的 jsp 文件未获取modelAttribute="contact1".

spring - Bean 名称的 BindingResult 和普通目标对象都不是

3 回答 3

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