Spring Validator werfen Ausnahme

Question

Wenn ich den folgenden Code ausführen und drücken Sie URL, um addEmployee() -Methode aufzurufen. Der Code bricht bei Validationszeit: ich die folgende Fehlermeldung erhalten:

java.lang.IllegalStateException: Neither BindingResult nor plain target object for bean name 'command' available as request attribute 

Die Projektstruktur ist: Model-Klasse:

public class Employee { 
    private int empId; 
    private String name; 
    private String password; 
    private String gender; 
    private Long salary; 
    private int age; 
    private List<String> courses; 
    private String tutor; 
    getters and setters() 
} 

Controller-Klasse:

@Controller 

public class EmployeeController { 

    @Autowired 
    @Qualifier("formValidator") 
    private Validator validator; 

    @InitBinder 
    private void initBinder(WebDataBinder binder) { 
     binder.setValidator(validator); 
    } 

    @RequestMapping(value = "/employee", method = RequestMethod.GET) 
    public ModelAndView employee() { 
     List<String> courses = new ArrayList<String>(); 
     courses.add("Maths"); 
     courses.add("Physics"); 
     courses.add("Geometry"); 
     courses.add("Algebra"); 
     courses.add("Painting"); 

     List<String> genders = new ArrayList<String>(); 
     genders.add("Male"); 
     genders.add("Female"); 

     List<String> tutors = new ArrayList<String>(); 
     tutors.add("Mrs Smith"); 
     tutors.add("Mr Johnson"); 
     tutors.add("Mr Clarks"); 

     // default bean name is command 
     ModelAndView modelAndView = new ModelAndView("employeeForm", "command", new Employee()); 
     modelAndView.addObject("tutors", tutors); 
     modelAndView.addObject("genders", genders); 
     modelAndView.addObject("courses", courses); 

     return modelAndView; 
    } 

    @RequestMapping(value = "/addEmployee", method = RequestMethod.POST) 
    public String addEmployee(@Valid @ModelAttribute Employee employee, BindingResult result, ModelMap model) { 
     if (result.hasErrors()) { 
      return "employeeForm"; 
     } 
     model.addAttribute("empId", employee.getEmpId()); 
     model.addAttribute("name", employee.getName()); 
     model.addAttribute("password", employee.getPassword()); 
     model.addAttribute("gender", employee.getGender()); 
     model.addAttribute("salary", employee.getSalary()); 
     model.addAttribute("age", employee.getAge()); 
     model.addAttribute("courses", employee.getCourses()); 
     model.addAttribute("tutor", employee.getTutor()); 
     return "employeeDetail"; 
    } 

} 

Validator Klasse:

public class FormValidator implements Validator { 


    public boolean supports(Class<?> paramClass) { 
     return Employee.class.equals(paramClass); 
    } 

    public void validate(Object obj, Errors errors) { 
     try { 
      Employee emp = (Employee) obj; 
      ValidationUtils.rejectIfEmptyOrWhitespace(errors, "empId", "valid.empId"); 
      ValidationUtils.rejectIfEmptyOrWhitespace(errors, "name", "valid.name"); 
      ValidationUtils.rejectIfEmptyOrWhitespace(errors, "password", "valid.password"); 
      ValidationUtils.rejectIfEmptyOrWhitespace(errors, "gender", "valid.gender"); 
      ValidationUtils.rejectIfEmptyOrWhitespace(errors, "salary", "valid.salary"); 
      ValidationUtils.rejectIfEmptyOrWhitespace(errors, "age", "valid.age"); 
      ValidationUtils.rejectIfEmptyOrWhitespace(errors, "tutor", "valid.tutor"); 
      List<String> courses = emp.getCourses(); 
      if (courses == null || courses.size() < 2) { 
       errors.rejectValue("courses", "valid.courses"); 
      } 
     } catch (Exception e) { 
      e.printStackTrace(); 
     } 
    } 
} 

{Name} -servlet.xml

<!-- Enable annotation driven controllers, validation etc... --> 
<mvc:annotation-driven></mvc:annotation-driven> 

<context:component-scan base-package="com.bits.emp.controller"></context:component-scan> 
<bean id="messageSource" 
    class="org.springframework.context.support.ResourceBundleMessageSource"> 
    <property name="basename" value="validation" /> 
</bean> 

<bean id="formValidator" class="com.bits.emp.validator.FormValidator" /> 


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

employeeForm.jsp

<form:form method="POST" action="/sdnext/addEmployee"> 
    <table> 
     <tr> 
      <td width="127"><form:label path="empId">Employee Id:</form:label></td> 
      <td width="102"><form:input path="empId" /></td> 
      <td><form:errors path="empId" cssStyle="color: #ff0000;" /></td> 

     </tr> 
     <tr> 
      <td><form:label path="name">Employee Name:</form:label></td> 
      <td><form:input path="name" /></td> 
      <td><form:errors path="name" cssStyle="color: #ff0000;" /></td> 

     </tr> 
     <tr> 
      <td><form:label path="password">Password :</form:label></td> 
      <td><form:password path="password" showPassword="true" /></td> 
      <td><form:errors path="password" cssStyle="color: #ff0000;" /></td> 

     </tr> 
     <tr> 
      <td><form:label path="gender">Gender :</form:label></td> 
      <td><form:radiobuttons path="gender" items="${genders}" /></td> 
      <td><form:errors path="gender" cssStyle="color: #ff0000;" /></td> 

     </tr> 
     <tr> 
      <td><form:label path="salary">Employee Salary:</form:label></td> 
      <td><form:input path="salary" /></td> 
      <td><form:errors path="salary" cssStyle="color: #ff0000;" /></td> 

     </tr> 
     <tr> 
      <td><form:label path="age">Employee Age:</form:label></td> 
      <td><form:input path="age" /></td> 
      <td><form:errors path="age" cssStyle="color: #ff0000;" /></td> 

     </tr> 
     <tr> 
      <td><form:label path="courses">Courses:</form:label></td> 
      <td><form:checkboxes path="courses" items="${courses}" /></td> 
      <td><form:errors path="courses" cssStyle="color: #ff0000;" /></td> 

     </tr> 
     <tr> 
      <td>Please select your tutor:</td> 
      <td><form:select path="tutor"> 
        <form:option value="" label="...." /> 
        <form:options items="${tutors}" /> 
       </form:select></td> 
      <td><form:errors path="tutor" cssStyle="color: #ff0000;" /></td> 
     </tr> 

     <tr> 
      <td colspan="2"><input type="submit" value="Submit" /></td> 
     </tr> 
    </table> 
</form:form> 

Bitte legen nahe, warum ich diese Störung erhalte und wie diese zu lösen. Danke im Voraus.

Answer 1

Die addEmployee Methode in Ihrer Controller-Klasse hat falsche Parameter. Sie sollten das Modellattribut definieren, das im Formular verwendet wurde. Versuchen Sie, Ihre Methode so zu ändern: