Question

我知道这个问题已经被提出并以不同的方式回答，但是对于Spring来说，一切都是不同的。

我是Spring 4的新手 - MVS，只是想创建我的第一个MVC - HelloWorld实现并得到错误

java.lang.IllegalStateException：既不是BindingResult也不是plain bean name＆＃39;命令的目标对象＆＃39;可用作请求属性 org.springframework.web.servlet.support.BindStatus。（BindStatus.java:141） org.springframework.web.servlet.tags.form.AbstractDataBoundFormElementTag.get

我的web.xml如下所示：

Archetype创建Web应用程序你好，世界 org.springframework.web.servlet.DispatcherServlet 1 你好，世界 / contextConfigLocation的 /WEB-INF/HelloWorld-servlet.xml org.springframework.web.context.ContextLoaderListener 我的HelloWorld-servlet.xml是这样的：

<context:component-scan base-package="com.programcreek.helloworld.controller" />

<bean
    class="org.springframework.web.servlet.view.InternalResourceViewResolver">
    <property name="prefix">
        <value>/</value>
    </property>
    <property name="suffix">
        <value>.jsp</value>
    </property>
</bean>

我的student.jsp看起来像这样：

     <%@taglib uri="http://www.springframework.org/tags/form" prefix="form"%>
<html>
<head>
    <title>Spring MVC Form Handling</title>
</head>
<body>

<h2>2 Student Information 2</h2>


<form:form method="POST" action="/HelloWorld/addStudent" >
   <table>
    <tr>
        <td><form:label path="name">Name</form:label></td>
        <td><form:input path="name" /></td>
    </tr>
    <tr>
        <td><form:label path="age">Age</form:label></td>
        <td><form:input path="age" /></td>
    </tr>
    <tr>
        <td><form:label path="id">id</form:label></td>
        <td><form:input path="id" /></td>
    </tr>
    <tr>
        <td colspan="2">
            <input type="submit" value="Submit"/>
        </td>
    </tr>
</table>  
</form:form>
</body>
</html>

和我的StudentController.java如下：

package com.programcreek.helloworld.controller;

import org.springframework.stereotype.Controller;
import org.springframework.ui.ModelMap;
import org.springframework.validation.BindingResult;
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
@RequestMapping("/")
public class StudentController {

   @RequestMapping(value = "/student", method = RequestMethod.GET)
   public ModelAndView student() {

      return new ModelAndView("student", "command2", new Student());
   }



   @RequestMapping(value = "/addStudent", method = RequestMethod.POST)
   public String addStudent(@ModelAttribute("HelloWorld")Student student, 
   ModelMap model) {

       System.out.println("Controller2");
      model.addAttribute("name", student.getName());
      model.addAttribute("age", student.getAge());
      model.addAttribute("id", student.getId());

      return "result";
   }
}

我总是阅读很多示例并将示例代码传输到我的eclipse进行试用，但是这个学生的案例来自一个旧的例子（Spring 2.4）。

感谢您帮助我找出问题所在。（我知道弹簧文件）

Answer 1

我已经在我的系统上执行了你的代码

您将从控制器类返回

return new ModelAndView("student", "command2", new Student());

所以你有map＆＃34; command2＆＃34;使用commandName的形式   student.jsp

的CommandName =＆＃34;命令2＆＃34;在你的student.jsp中，如下所示

<form:form method="POST" commandName="command2" action="/HelloWorld/addStudent" >

项目的完整源代码：

student.java

package com.programcreek.helloworld.controller;

public class Student {
       private Integer age;
       private String name="";
       private Integer id;
       public Student(){

       }
       public void setAge(Integer age) {
          this.age = age;
       }
       public Integer getAge() {
          return age;
       }

       public void setName(String name) {
          this.name = name;
       }
       public String getName() {
          return name;
       }

       public void setId(Integer id) {
          this.id = id;
       }
       public Integer getId() {
          return id;
       }
    }

StudentController.java

package com.programcreek.helloworld.controller;

    import org.springframework.stereotype.Controller;
    import org.springframework.ui.ModelMap;
    import org.springframework.validation.BindingResult;
    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
    @RequestMapping("/")
    public class StudentController {

        @RequestMapping(value = "/student", method = RequestMethod.GET)
           public ModelAndView student() {

              return new ModelAndView("student", "command2", new Student());
           }



           @RequestMapping(value = "/addStudent", method = RequestMethod.POST)
           public ModelAndView addStudent(@ModelAttribute("HelloWorld")Student student) {
               ModelAndView modelAndView = new ModelAndView();

               System.out.println("Controller2");
               modelAndView.addObject("name", student.getName());
               modelAndView.addObject("age", student.getAge());
               modelAndView.addObject("id", student.getId());
               modelAndView.setViewName("result");


              return modelAndView;
           }
        }

的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">



    <servlet>
        <servlet-name>DefaultServlet</servlet-name>
        <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
    </servlet>

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


</web-app>

DefaultServlet-servlet.xml中

<?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"
    xsi:schemaLocation="http://www.springframework.org/schema/beans
http://www.springframework.org/schema/beans/spring-beans.xsd
http://www.springframework.org/schema/context
http://www.springframework.org/schema/context/spring-context.xsd">

    <context:component-scan base-package="com.programcreek.helloworld.controller" />
    <!-- <context:component-scan base-package="com.packt.webstore.domain.repository.impl" />
    <context:component-scan base-package="com.packt.webstore.service.impl" /> -->

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


</beans>

student.jsp

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

<html>
<head>
    <title>Spring MVC Form Handling</title>
</head>
<body>

<h2>2 Student Information 2</h2>


<form:form method="POST" commandName="command2" action="addStudent" >
   <table>
    <tr>
        <td><form:label path="name">Name</form:label></td>
        <td><form:input path="name" /></td>
    </tr>
    <tr>
        <td><form:label path="age">Age</form:label></td>
        <td><form:input path="age" /></td>
    </tr>
    <tr>
        <td><form:label path="id">id</form:label></td>
        <td><form:input path="id" /></td>
    </tr>
    <tr>
        <td colspan="2">
            <input type="submit" value="Submit"/>
        </td>
    </tr>
</table>  
</form:form>
</body>
</html>

目录结构：

执行结果

Spring 4 /既不是BindingResult也不是普通的目标对象

1 个答案: