Validator 인터페이스를 이용한 폼 검증

 

■ Validator : org.springframework.validation.Validator 인터페이스는 객체를 검증할 때 사용

 ◆ Validator 인터페이스의 메서드

boolean supports(Class<?> clazz)	Validator가 해당 클래스에 대한 값 검증을 지원하는 지의 여부를 리턴
void validate(Object target, Errors errors)	target 객체에 대한 검증을 실행. 검증 결과에 문제가 있을 경우 errors 객체에 에러 정보 저장

 

 ◆ 커맨드 객체에 검증코드 추가 방법

   ● @RequestMapping 어노테이션 메서드에서 커맨드 객체 다음 파라미터로 BindingResult 타입이나 Errors 타입의 파라미터 추가

   ● 메서드 내에서 Validator 객체를 생성 후 validate() 메서드에 커맨드 객체와 BindingResult 또는 Errors 타입의 파라미터를 전달

   ● Errors.hasErrors() 메서드를 이용해서 에러가 존재하는 지 확인하고, 에러가 존재할 경우 알맞은 처리를 수행

 

 

UserVO.java

package sp.mvc.vo;   public class UserVO {  private String userName;  private String address;  private String fruit;    public String getUserName() {   return userName;  }  public void setUserName(String userName) {   this.userName = userName;  }  public String getAddress() {   return address;  }  public void setAddress(String address) {   this.address = address;  }  public String getFruit() {   return fruit;  }  public void setFruit(String fruit) {   this.fruit = fruit;  }    @Override  public String toString() {   return "UserVO [userName=" + userName + ", address=" + address + ", fruit=" + fruit + "]";  } }

 

UserVoValidator.java

package sp.mvc.validator; import org.springframework.validation.Errors; import org.springframework.validation.Validator; import sp.mvc.vo.UserVO;   public class UserVoValidator implements Validator {  @Override  public boolean supports(Class<?> clazz) {   // TODO Auto-generated method stub   System.out.println("--- UserVoValidator.supports() ---");   return UserVO.class.isAssignableFrom(clazz);  }    @Override  public void validate(Object target, Errors errors) {   // TODO Auto-generated method stub   System.out.println("--- UserVoValidator.validate() ---");      UserVO userVo = (UserVO)target;      if(userVo.getUserName() == null || userVo.getUserName().trim().isEmpty()){    errors.rejectValue("id", "required");   }      if(userVo.getAddress() == null || userVo.getAddress().trim().isEmpty()){    errors.rejectValue("address", "required");   }  }   }

 

UserController.java

package sp.mvc.controller; import javax.servlet.http.HttpServletRequest; import org.springframework.stereotype.Controller; import org.springframework.ui.Model; 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; import sp.mvc.validator.UserVoValidator; import sp.mvc.vo.UserVO;   @Controller @RequestMapping("/userForm.sp") public class UserController {    @ModelAttribute("userVo")  public UserVO initForm(HttpServletRequest req){   System.out.println("---- @ModelAttribute ----");      if(req.getMethod().equalsIgnoreCase("GET")){    System.out.println("---- @ModelAttribute : GET ----");        UserVO userVo = new UserVO();    userVo.setUserName("input name");    userVo.setAddress("input address");    userVo.setFruit("input fruit");        return userVo;   }else{    System.out.println("---- @ModelAttribute : POST ----");        return new UserVO();   }    }      @RequestMapping(method=RequestMethod.GET)  public String userForm(){   System.out.println("---- UserController.userForm() ----");      return "user/userForm";  }    @RequestMapping(method=RequestMethod.POST)  public String userSave(@ModelAttribute("userVo") UserVO userVo, BindingResult result){   System.out.println("---- UserController.userSave() ----");   System.out.println("userInfo : " + userVo.toString());      UserVoValidator userVoValidator = new UserVoValidator();   userVoValidator.validate(userVo, result);      if(result.hasErrors()){    System.out.println("---- validator : " + result.getErrorCount()+ "개 errors ----");        //다시 GET 방식으로 호출    return "redirect:/userForm.sp";   }       System.out.println("---- validator : no errors ----");   return "user/userInfo";  }   }

 

main_config.xml

<?xml version="1.0" encoding="UTF-8"?> <beans xmlns="http://www.springframework.org/schema/beans"  xmlns:context="http://www.springframework.org/schema/context"  xmlns:p="http://www.springframework.org/schema/p"  xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"  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">  <context:annotation-config/>  <context:component-scan base-package="sp.mvc.controller"/>  <!-- bean class="org.springframework.web.servlet.mvc.annotation.DefaultAnnotationHandlerMapping" p:alwaysUseFullPath="true"/ -->  <!-- bean class="org.springframework.web.servlet.mvc.annotation.AnnotationMethodHandlerAdapter" p:alwaysUseFullPath="true"/ -->      <!-- ViewResolver 설정 -->  <bean id="internalResource" class="org.springframework.web.servlet.view.InternalResourceViewResolver">   <property name="prefix" value="jsp/"></property>   <property name="suffix" value=".jsp"></property>  </bean>    <!-- 각종 bean 설정 -->   </beans>

 

userForm.jsp

<%@ page language="java" contentType="text/html; charset=UTF-8"     pageEncoding="UTF-8"%> <%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %>  <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> <html> <head> <meta http-equiv="Content-Type" content="text/html; charset=UTF-8"> <title>회원정보 입력</title> </head> <body> <form action="userForm.sp" method="post">  <table border="1">   <tr>    <td>이름</td>    <td><input type="text" name="userName" value="${userVo.userName}"/></td>   </tr>   <tr>    <td>주소</td>    <td><input type="text" name="address" value="${userVo.address}"/></td>   </tr>  </table>   <input type="submit" name="submit" value="전송"/> </form> </body> </html>

 

userInfo.jsp

<%@ page language="java" contentType="text/html; charset=UTF-8"     pageEncoding="UTF-8"%> <%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %>    <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> <html> <head> <meta http-equiv="Content-Type" content="text/html; charset=UTF-8"> <title>회원정보 출력</title> </head> <body>  <table border="1">   <tr>    <td>이름</td>    <td>${userVo.userName}</td>   </tr>   <tr>    <td>주소</td>    <td>${userVo.address}</td>   </tr>  </table> </body> </html>

 

 

결과 - [에러가 없는 경우]

요청 URL    http://localhost:8090/spring303/userForm.sp         ---- @ModelAttribute ---- ---- @ModelAttribute : GET ---- ---- UserController.userForm() ---- ---- @ModelAttribute ---- ---- @ModelAttribute : POST ---- ---- UserController.userSave() ---- userInfo : UserVO [userName=스누피, address=제주도 321, fruit=null] --- UserVoValidator.validate() --- ---- validator : no errors ----

 

결과 - [에러가 존재하는 경우]

요청 URL    http://localhost:8090/spring303/userForm.sp         ---- @ModelAttribute ---- ---- @ModelAttribute : GET ---- ---- UserController.userForm() ---- ---- @ModelAttribute ---- ---- @ModelAttribute : POST ---- ---- UserController.userSave() ---- userInfo : UserVO [userName=스누피, address=, fruit=null] --- UserVoValidator.validate() --- ---- validator : 1개 errors ---- ---- @ModelAttribute ---- ---- @ModelAttribute : GET ---- ---- UserController.userForm() ----

 

 

 

[참고자료] Spring 3.0 프로그래밍-최범균