Spring中的WebDataBinder如何使用？

 1 package com.concretepage.validators; 2 import org.springframework.stereotype.Component; 3 import org.springframework.validation.Errors; 4 import org.springframework.validation.ValidationUtils; 5 import org.springframework.validation.Validator; 6 import com.concretepage.User; 7 @Component 8 public class UserValidator implements Validator  { 9     @Override10     public boolean supports(Class clazz) {11         return User.class.isAssignableFrom(clazz);12     }13     @Override14     public void validate(Object target, Errors errors) {15         User user = (User)target;16         ValidationUtils.rejectIfEmptyOrWhitespace(errors, "name", "","Username is empty");17         ValidationUtils.rejectIfEmptyOrWhitespace(errors, "password", "", "Password is empty");18         if (user.getName().length()<5) {19             errors.rejectValue("name","", "Username length is less than 5");20         }21     }22 }

 1 package com.concretepage.validators; 2 import org.springframework.stereotype.Component; 3 import org.springframework.validation.Errors; 4 import org.springframework.validation.ValidationUtils; 5 import org.springframework.validation.Validator; 6 import com.concretepage.User; 7 @Component 8 public class EmailValidator implements Validator { 9     @Override10     public boolean supports(Class clazz) {11         return User.class.isAssignableFrom(clazz);12     }13     @Override14     public void validate(Object target, Errors errors) {15         User user = (User)target;16         ValidationUtils.rejectIfEmptyOrWhitespace(errors, "email", "","Email is empty");17         if (!user.getEmail().contains("@")) {18             errors.rejectValue("email","", "Email is not valid.");19         }20     }21 }

 1 package com.concretepage;
 2 import java.util.Date;
 3 public class User {
 4     private String name;
 5     private String password;
 6     private String email;
 7     private Date dob;
 8     public String getName() {
 9         return name;
10     }
11     public void setName(String name) {
12         this.name = name;
13     }
14     public String getPassword() {
15         return password;
16     }
17     public void setPassword(String password) {
18         this.password = password;
19     }
20     public String getEmail() {
21         return email;
22     }
23     public void setEmail(String email) {
24         this.email = email;
25     }
26     public Date getDob() {
27         return dob;
28     }
29     public void setDob(Date dob) {
30         this.dob = dob;
31     }
32 }

 1 package com.concretepage; 2 import java.text.SimpleDateFormat; 3 import java.util.Date; 4  5 import javax.validation.Valid; 6  7 import org.springframework.beans.factory.annotation.Autowired; 8 import org.springframework.beans.propertyeditors.CustomDateEditor; 9 import org.springframework.stereotype.Controller;10 import org.springframework.ui.ModelMap;11 import org.springframework.validation.BindingResult;12 import org.springframework.web.bind.WebDataBinder;13 import org.springframework.web.bind.annotation.InitBinder;14 import org.springframework.web.bind.annotation.ModelAttribute;15 import org.springframework.web.bind.annotation.RequestMapping;16 import org.springframework.web.bind.annotation.RequestMethod;17 import org.springframework.web.servlet.ModelAndView;18 19 import com.concretepage.validators.EmailValidator;20 import com.concretepage.validators.UserValidator;21 @Controller22 @RequestMapping("/myworld")23 public class MyWorldController {24     @Autowired25     private UserValidator userValidator;26     @Autowired27     private EmailValidator emailValidator;28 29     @RequestMapping(value="signup", method = RequestMethod.GET)30     public ModelAndView user(){31         return new ModelAndView("user","user",new User());32     }33     @InitBinder34     public void dataBinding(WebDataBinder binder) {35         binder.addValidators(userValidator, emailValidator);36         SimpleDateFormat dateFormat = new SimpleDateFormat("dd/MM/yyyy");37         dateFormat.setLenient(false);38         binder.registerCustomEditor(Date.class, "dob", new CustomDateEditor(dateFormat, true));39     }40     41     @RequestMapping(value="save", method = RequestMethod.POST)42     public String createUser(@ModelAttribute("user") @Valid User user,BindingResult result, ModelMap model) {43         if(result.hasErrors()) {44             return "user";45         }46         System.out.println("Name:"+ user.getName());47         System.out.println("Email:"+ user.getEmail());48         System.out.println("Date of Birth:"+ user.getDob());49         model.addAttribute("msg", "Welcome to My World!");50         return "success";51     }    
52 }

    User Name:   
              Password :   
               Email :   
               Date of Birth :