是的，我读过这是一个很常见的问题，但是阅读那些帖子并没有真正帮助我。
简短的故事是我想在 showAllComments.jsp 上提交一个表单
<form:form method="post" action="postNewComment.html">
<table>
<tr>
<td><form:label path="comment">
COMMENT
</form:label></td>
<td><form:input path="comment" /></td>
</tr>
<tr>
<td colspan="2"><input type="submit"
value="WRITE" /></td>
</tr>
</table>
</form:form>
这是控制器：
@Controller
@SessionAttributes
public class CommentController {
@Autowired
private CommentService commentService;
@RequestMapping(value = "/postNewComment", method = RequestMethod.POST)
public ModelAndView showAllUsers(@ModelAttribute("command") Comment comment, BindingResult result) {
System.out.println(comment.getComment());
Map<String, Object> model = new HashMap<String, Object>();
model.put("COMMENTS", commentService.getComments());
return new ModelAndView("showAllComments", model);
}
}
结果如下： java.lang.IllegalStateException: Bean name 'command' 的 BindingResult 和普通目标对象都不能用作请求属性
但是您可能需要从头看到整个故事：用户通过单击在 index.jsp 上启动应用程序
<a href="toLoginPage.html">Log in</a>
该链接将他带到 LoginController
@RequestMapping("/toLoginPage")
public ModelAndView goToLoginPage() {
return new ModelAndView("login", "command", new User());
}
然后他被带到 login.jsp，在那里他提供了他的用户名和密码。
<form:form method="post" action="log_in.html">
<input type="text" name="uName" />
<input type="password" name="pW" />
<input type="submit" value="Log IN">
</form:form>
他提交表单并被带回 LoginController
@RequestMapping(value = "/log_in", method = RequestMethod.POST)
public ModelAndView tryToLogin(@RequestParam("uName") String uName, @RequestParam("pW") String pW, HttpServletResponse response, HttpServletRequest request) {
ModelAndView ret = new ModelAndView("login", "command", new User());
User user = userService.existingUser(uName, pW);
loggedInUser = new User();
if (user != null) {
Map<String, Object> model = new HashMap<String, Object>();
model.put("COMMENTS", allComments);
model.put("LOGGED_IN_USER", loggedInUser);
ret = ModelAndView("showAllComments", model);
}
return ret;
}
成功登录后，他在 showAllComments 页面上看到了所有评论，他应该能够添加自己的评论，但提交上述表单会引发上述异常。我觉得有些东西不见了，但我不知道它是什么。只是为了记录，我展示了 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">
<display-name>Spring3MVC</display-name>
<servlet>
<servlet-name>spring</servlet-name>
<servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
<load-on-startup>1</load-on-startup>
</servlet>
<servlet-mapping>
<servlet-name>spring</servlet-name>
<url-pattern>*.html</url-pattern>
</servlet-mapping>
<welcome-file-list>
<welcome-file>index.jsp</welcome-file>
</welcome-file-list>
</web-app>
和 spring-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:context="http://www.springframework.org/schema/context"
xmlns:tx="http://www.springframework.org/schema/tx"
xsi:schemaLocation="
http://www.springframework.org/schema/beans
http://www.springframework.org/schema/beans/spring-beans-3.0.xsd
http://www.springframework.org/schema/context
http://www.springframework.org/schema/context/spring-context-3.0.xsd
http://www.springframework.org/schema/tx
http://www.springframework.org/schema/tx/spring-tx-3.0.xsd">
<context:property-placeholder location="classpath:jdbc.properties" />
<context:component-scan base-package="net" />
<tx:annotation-driven transaction-manager="hibernateTransactionManager" />
<bean id="viewResolver"
class="org.springframework.web.servlet.view.UrlBasedViewResolver">
<property name="viewClass"
value="org.springframework.web.servlet.view.JstlView" />
<property name="prefix" value="/WEB-INF/jsp/" />
<property name="suffix" value=".jsp" />
</bean>
<bean id="dataSource"
class="org.springframework.jdbc.datasource.DriverManagerDataSource">
<property name="driverClassName" value="${database.driver}" />
<property name="url" value="${database.url}" />
<property name="username" value="${database.user}" />
<property name="password" value="${database.password}" />
</bean>
<bean id="sessionFactory"
class="org.springframework.orm.hibernate3.annotation.AnnotationSessionFactoryBean">
<property name="dataSource" ref="dataSource" />
<property name="annotatedClasses">
<list>
<value>net.model.User</value>
<value>net.model.Comment</value>
</list>
</property>
<property name="hibernateProperties">
<props>
<prop key="hibernate.dialect">${hibernate.dialect}</prop>
<prop key="hibernate.show_sql">${hibernate.show_sql}</prop>
</props>
</property>
</bean>
<bean id="hibernateTransactionManager"
class="org.springframework.orm.hibernate3.HibernateTransactionManager">
<property name="sessionFactory" ref="sessionFactory" />
</bean>
<bean id="messageSource"
class="org.springframework.context.support.ReloadableResourceBundleMessageSource">
<property name="basename" value="classpath:messages" />
<property name="defaultEncoding" value="UTF-8" />
</bean>
<bean id="localeChangeInterceptor"
class="org.springframework.web.servlet.i18n.LocaleChangeInterceptor">
<property name="paramName" value="lang" />
</bean>
<bean id="localeResolver"
class="org.springframework.web.servlet.i18n.CookieLocaleResolver">
<property name="defaultLocale" value="en" />
</bean>
<bean id="handlerMapping"
class="org.springframework.web.servlet.mvc.annotation.DefaultAnnotationHandlerMapping">
<property name="interceptors">
<ref bean="localeChangeInterceptor" />
</property>
</bean>
</beans>