Help with Creating Custom Annotation for Form Validation

[trishasales]

Hi,

I am currently making a form for user account creation and two of the fields are for password and the confirmation of password. I would like to show an error message like the ones from Hibernate Validator saying that the two passwords should match if the two passwords entered by the user aren't equal. I hope someone can help me with this.

Thanks in advance.

PS: I am using Spring 3 Framework and Hibernate Validator for form validation. I am not using the SimpleFormController in any of my classes and I don't intend on using it since it's already deprecated.

[seyn]

Hi,

you can implement your own constraint annotaton and use it for such kind of requirements.

import java.lang.annotation.Documented;
import java.lang.annotation.ElementType;
import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;
import java.lang.annotation.Target;

import javax.validation.Constraint;
import javax.validation.Payload;

@Target( { ElementType.TYPE, ElementType.ANNOTATION_TYPE })
@Retention(RetentionPolicy.RUNTIME)
@Constraint(validatedBy = FieldMatchValidator.class)
@Documented
public @interface FieldMatch {
	String message() default "{validator.fieldmatch}";

	Class<?>[] groups() default {};

	Class<? extends Payload>[] payload() default {};

	/**
	 * @return The first field
	 */
	String first();

	/**
	 * @return The second field
	 */
	String second();

	/**
	 * Defines several <code>@FieldMatch</code> annotations on the same element
	 * 
	 * @see FieldMatch
	 */
	@Target( { ElementType.TYPE, ElementType.ANNOTATION_TYPE })
	@Retention(RetentionPolicy.RUNTIME)
	@Documented
	@interface List {
		FieldMatch[] value();
	}
}

and implementation

import javax.validation.ConstraintValidator;
import javax.validation.ConstraintValidatorContext;

import org.apache.commons.beanutils.BeanUtils;

public class FieldMatchValidator implements
		ConstraintValidator<FieldMatch, Object> {
	private String firstFieldName;
	private String secondFieldName;

	public void initialize(final FieldMatch constraintAnnotation) {
		firstFieldName = constraintAnnotation.first();
		secondFieldName = constraintAnnotation.second();
	}

	public boolean isValid(final Object value,
			final ConstraintValidatorContext context) {
		try {
			final Object firstObj = BeanUtils
					.getProperty(value, firstFieldName);
			final Object secondObj = BeanUtils.getProperty(value,
					secondFieldName);

			return firstObj == null && secondObj == null || firstObj != null
					&& firstObj.equals(secondObj);
		} catch (final Exception ignore) {
			// ignore
		}
		return true;
	}
}

and you can use like

@FieldMatch.List( { @FieldMatch(first = "password", second = "password2", message = "The password fields must match") })

for details http://stackoverflow.com/questions/1...idator-jsr-303

[trishasales]

Hi,

Thank you very much for the reply. I would just like to ask how am I going to show the message specified in the annotation? I am bit confused because I am used to putting validation annotations above fieldnames in my POJO. However, in the example you've given, the validation annotation is specified above the class itself. What model attribute should I add in the POST method of my controller for me to be able to show it with the <form:errors path=""/> tag?

[seyn]

Hi,

Thank you very much for the reply. I would just like to ask how am I going to show the message specified in the annotation? I am bit confused because I am used to putting validation annotations above fieldnames in my POJO. However, in the example you've given, the validation annotation is specified above the class itself. What model attribute should I add in the POST method of my controller for me to be able to show it with the <form:errors path=""/> tag?

"password" and "password2" are the names of my fields in pojo so you can stil put annotations above fields and use errors tag like <form:errors path="password"/> in jsp

[trishasales]

Hi,

I still cannot display the error message from the @FieldMatch annotation. Am I missing something? Here are my codes:

ApplicationUser.java (POJO):

package ETPS.web;

import java.util.Calendar;
import java.util.GregorianCalendar;

import org.hibernate.validator.constraints.Length;
import org.hibernate.validator.constraints.NotEmpty;

import ETPS.web.constraints.FieldMatch;

@FieldMatch(first = "password", second = "confirmPassword", message = "The password fields must match.")
public class ApplicationUser {

	@NotEmpty(message = "User ID is a required field.")
	@Length(min = 4, message = "Must contain 4 characters.")
	private String userId;
	
	@NotEmpty(message = "Name of User is a required field.")
	private String nameOfUser;
	
	@NotEmpty(message = "Password is a required field.")
	private String password;
	
	@NotEmpty(message = "Please re-enter password.")
	private String confirmPassword;
	
	@NotEmpty(message = "Role is a required field.")
	private String role;

	private String enrollmentDate;
	private String userView;
	
	public String getUserId() {
		return userId;
	}
	
	public void setUserId(String userId) {
		this.userId = userId;
	}
	
	public String getNameOfUser() {
		return nameOfUser;
	}
	
	public void setNameOfUser(String nameOfUser) {
		this.nameOfUser = nameOfUser;
	}
	
	public String getPassword() {
		return password;
	}
	
	public void setPassword(String password) {
		this.password = password;
	}
	
	public String getConfirmPassword() {
		return confirmPassword;
	}
	
	public void setConfirmPassword(String confirmPassword) {
		this.confirmPassword = confirmPassword;
	}
	
	public String getRole() {
		return role;
	}
	
	public void setRole(String role) {
		this.role = role;
	}
	
	public String getUserView(int i) {
		switch (i) {
		case 0:
			this.userView = "/WEB-INF/jsp/includes/adminMainMenu.jsp";
		break;
		case 1:
			this.userView = "/WEB-INF/jsp/includes/superMainMenu.jsp";
		break;
		case 2:
			this.userView = "/WEB-INF/jsp/includes/userMainMenu.jsp";
		break;
		case 3:
			this.userView = "/WEB-INF/jsp/includes/operMainMenu.jsp";
		break;	
		}
		
		return userView;
	}
	
}

RegisterApplicationUserController.java:

package ETPS.web.controllers;

import java.util.ArrayList;
import java.util.List;

import javax.validation.Valid;

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 ETPS.web.ApplicationUser;
import ETPS.web.managers.ApplicationUserManager;

@Controller
@RequestMapping(value = "/registerApplicationUser")
public class RegisterApplicationUserController {

	ApplicationUserManager applicationUserManager = new ApplicationUserManager();
	
	public ApplicationUserManager getLoginManager() {
		return applicationUserManager;
	}
	
	public void setLoginManager(ApplicationUserManager applicationUserManager) {
		this.applicationUserManager = applicationUserManager;
	}
	
	@ModelAttribute("roles")
	public List<String> getRoles() {
		List<String> roles = new ArrayList<String>();
		roles.add("Administrator");
		roles.add("User - Supervisor");
		roles.add("User");
		roles.add("Operator");
		
		return roles;
	}
	
	@RequestMapping(method = RequestMethod.GET)
	public String registerApplicationUserForm(Model model) {
		ApplicationUser applicationUser = new ApplicationUser();
		model.addAttribute("userView", applicationUser.getUserView(0));
		model.addAttribute("registerApplicationUserForm", applicationUser);
		
		return "registerApplicationUser";
	}
	
	@RequestMapping(method = RequestMethod.POST)
	public String registerApplicationUser(@ModelAttribute("registerApplicationUserForm") 
			@Valid ApplicationUser applicationUser, BindingResult result, Model model) {
		String userId = applicationUser.getUserId();
		String nameOfUser = applicationUser.getNameOfUser();
		String password = applicationUser.getPassword();
		String role = applicationUser.getRole();
		if (applicationUserManager.hasDuplicate(userId)) {
			model.addAttribute("errorMessage", "User already exists!");
			
			model.addAttribute("userView", applicationUser.getUserView(0));
			return "registerApplicationUser";
		} else if ((result.hasErrors())||
				!(applicationUserManager.registerApplicationUser(userId, 
						nameOfUser, password, role))) {
			model.addAttribute("userView", applicationUser.getUserView(0));
			
			return "registerApplicationUser";
		} else {
			model.addAttribute("userView", applicationUser.getUserView(0));
			model.addAttribute("userId", applicationUser.getUserId());
			model.addAttribute("nameOfUser", applicationUser.getNameOfUser());
			model.addAttribute("password", applicationUser.getPassword());
			model.addAttribute("confirmPassword", 
					applicationUser.getConfirmPassword());
			model.addAttribute("role", applicationUser.getRole());
			model.addAttribute("enrollmentDate", 
					applicationUserManager.getEnrollmentDate(userId));
			model.addAttribute(applicationUser);
			
			return "viewApplicationUser";
		}
	}
	
}

registerApplicationUser.jsp:

<%@ include file="/WEB-INF/jsp/includes/taglib-include.jsp" %>

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
	<head>
		<title>Electronic Tax Payment System &raquo; Application User Registration</title>
		<meta http-equiv="content-type" content="text/html;charset=UTF-8"/>
		<link rel="stylesheet" type="text/css" href="http://localhost:8080/ETPS/stylesheet.css"/>
	</head>
	<body>
		<div id="container">
			<c:import url="/WEB-INF/jsp/includes/header.jsp"/>
			<div class="content">
				<c:import url="${userView}"/>
				<div class="mainContent">
					<form:form modelAttribute="registerApplicationUserForm">
						<fieldset>
							<legend>Application User Information</legend>
							<p class="error"><c:out value="${errorMessage}"/></p>
							Please fill up the following form:
							<table>
								<tr>
									<td>User ID:</td>
									<td>
										<form:input path="userId" maxlength="4" size="4"/>
									</td>
									<td>
										<form:errors path="userId" cssClass="error"/>
									</td>
								</tr>
								<tr>
									<td>Name of User:</td>
									<td>
										<form:input path="nameOfUser" maxlength="50"/>
									</td>
									<td>
										<form:errors path="nameOfUser" cssClass="error"/>
									</td>
								</tr>
								<tr>
									<td>Password:</td>
									<td>
										<form:password path="password" maxlength="8"/>
									</td>
									<td>
										<form:errors path="password" cssClass="error"/>
									</td>
								</tr>
								<tr>
									<td>Confirm Password:</td>
									<td>
										<form:password path="confirmPassword" maxlength="8"/>
									</td>
									<td>
										<form:errors path="confirmPassword" cssClass="error"/>
									</td>
								</tr>
								<tr>
									<td>Role:</td>
									<td>
										<form:select path="role" items="${roles}"/>
									</td>
									<td>
										<form:errors path="role" cssClass="error"/>
									</td>
								</tr>
								<tr>
									<td></td>
									<td>
										<input type="submit" value="Submit"/>&nbsp;
										<input type="reset" value="Reset"/>
									</td>
									<td></td>
								</tr>
							</table>
						</fieldset>
					</form:form>
				</div>
			</div>
			<c:import url="/WEB-INF/jsp/includes/footer.jsp"/>
		</div>
	</body>
</html>

viewApplicationUser.jsp:

<%@ include file="/WEB-INF/jsp/includes/taglib-include.jsp" %>

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
	<head>
		<title>Electronic Tax Payment System</title>
		<meta http-equiv="content-type" content="text/html;charset=UTF-8"/>
		<link rel="stylesheet" type="text/css" href="http://localhost:8080/ETPS/stylesheet.css"/>
	</head>
	<body>
		<div id="container">
			<c:import url="/WEB-INF/jsp/includes/header.jsp"/>
			<div class="content">
				<c:import url="${userView}"/>
				<div class="mainContent">
					<fieldset>
						<legend>Application User Information</legend>
						<table>
							<tr>
								<td>User ID:</td>
								<td><c:out value="${userId}"/></td>
							</tr>
							<tr>
								<td>Name of User:</td>
								<td><c:out value="${nameOfUser}"/></td>
							</tr>
							<tr>
								<td>Password:</td>
								<td><c:out value="${password}"/></td>
							</tr>
							<tr>
								<td>Confirm Password:</td>
								<td><c:out value="${confirmPassword}"/></td>
							</tr>
							<tr>
								<td>Role:</td>
								<td><c:out value="${role}"/></td>
							</tr>
							<tr>
								<td>Enrollment Date:</td>
								<td><c:out value="${enrollmentDate}"/></td>
							</tr>
						</table>
					</fieldset>
				</div>
			</div>
			<c:import url="/WEB-INF/jsp/includes/footer.jsp"/>
		</div>
	</body>
</html>

[syalbi]

Use @NotBlank instead of @NotEmpty.
@NotBlank is for String and @NotEmpty is for Element/Object