Spring MVC Java Config : Part 2 Bean Validation and Exception Handler

It is always good to check the validity and integrity of form data before passing to business logic, let's see how to do it.





1.TOOLS AND ENV

IDE : Spring Tool Suite 3.7.3 
JDK : 1.8 
Tomcat : 8.0.18 
Spring : 4.2.6.RELEASE

 

2. POM.XML

	<?xml version="1.0" encoding="UTF-8"?>
	<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
	xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">
	<modelVersion>4.0.0</modelVersion>
	<groupId>org.junjun.spring.tutorials</groupId>
	<artifactId>spring-mvc-bean-validation</artifactId>
	<packaging>war</packaging>
	<version>1.0.0</version>
	<properties>
	<java.version>1.8</java.version>
	<org.springframework.version>4.2.6.RELEASE</org.springframework.version>
	<slf4j.version>1.7.10</slf4j.version>
	</properties>
	<dependencies>
	<dependency>
	<groupId>org.springframework</groupId>
	<artifactId>spring-context</artifactId>
	<version>${org.springframework.version}</version>
	</dependency>
	<dependency>
	<groupId>org.springframework</groupId>
	<artifactId>spring-webmvc</artifactId>
	<version>${org.springframework.version}</version>
	</dependency>
	<dependency>
	<groupId>javax.validation</groupId>
	<artifactId>validation-api</artifactId>
	<version>1.1.0.Final</version>
	</dependency>
	<dependency>
	<groupId>org.hibernate</groupId>
	<artifactId>hibernate-validator</artifactId>
	<version>5.1.2.Final</version>
	</dependency>
	<dependency>
	<groupId>org.slf4j</groupId>
	<artifactId>slf4j-log4j12</artifactId>
	<version>1.7.5</version>
	</dependency>
	<dependency>
	<groupId>javax.servlet</groupId>
	<artifactId>javax.servlet-api</artifactId>
	<version>3.1.0</version>
	<scope>provided</scope>
	</dependency>
	<!-- http://mvnrepository.com/artifact/javax.servlet.jsp/javax.servlet.jsp-api -->
	<dependency>
	<groupId>javax.servlet.jsp</groupId>
	<artifactId>javax.servlet.jsp-api</artifactId>
	<version>2.3.1</version>
	<scope>provided</scope>
	</dependency>
	<dependency>
	<groupId>javax.servlet</groupId>
	<artifactId>jstl</artifactId>
	<version>1.2</version>
	</dependency>
	</dependencies>
	<build>
	<plugins>
	<plugin>
	<groupId>org.apache.maven.plugins</groupId>
	<artifactId>maven-war-plugin</artifactId>
	<configuration>
	<failOnMissingWebXml>false</failOnMissingWebXml>
	</configuration>
	</plugin>
	<plugin>
	<groupId>org.apache.maven.plugins</groupId>
	<artifactId>maven-compiler-plugin</artifactId>
	<configuration>
	<source>${java.version}</source>
	<target>${java.version}</target>
	<compilerArgument>-Xlint:all</compilerArgument>
	<showWarnings>true</showWarnings>
	<showDeprecation>true</showDeprecation>
	</configuration>
	</plugin>
	</plugins>
	</build>
	</project>

view raw pom.xml hosted with ❤ by GitHub

Java Bean Validation API and Bean Validation  Provider (Hibernate) added.



3. SEPARATE ROOT AND WEB CONFIG

	package org.junjun.spring.tutorials.config;
	import org.springframework.web.context.WebApplicationContext;
	import org.springframework.web.servlet.DispatcherServlet;
	import org.springframework.web.servlet.FrameworkServlet;
	import org.springframework.web.servlet.support.AbstractAnnotationConfigDispatcherServletInitializer;
	public class ServletInitializer extends AbstractAnnotationConfigDispatcherServletInitializer {
	@Override
	protected Class<?>[] getRootConfigClasses() {
	return new Class[] { RootConfig.class };
	}
	@Override
	protected Class<?>[] getServletConfigClasses() {
	return new Class<?>[] { WebConfig.class };
	}
	@Override
	protected String[] getServletMappings() {
	return new String[] { "/" };
	}
	@Override
	protected FrameworkServlet createDispatcherServlet(WebApplicationContext servletAppContext) {
	DispatcherServlet dispatcherServlet = (DispatcherServlet) super.createDispatcherServlet(servletAppContext);
	dispatcherServlet.setThrowExceptionIfNoHandlerFound(true);
	return dispatcherServlet;
	}
	}

view raw ServletInitializer.java hosted with ❤ by GitHub

	package org.junjun.spring.tutorials.config;
	import org.springframework.context.annotation.Configuration;
	import org.springframework.context.annotation.Import;
	@Configuration
	@Import({ AppConfig.class })
	public class RootConfig {
	}

view raw RootConfig.java hosted with ❤ by GitHub

	package org.junjun.spring.tutorials.config;
	import org.springframework.context.annotation.ComponentScan;
	import org.springframework.context.annotation.Configuration;
	@Configuration
	@ComponentScan({ "org.junjun.spring.tutorials.service", "org.junjun.spring.tutorials.dao" })
	public class AppConfig {
	}

view raw AppConfig.java hosted with ❤ by GitHub

	package org.junjun.spring.tutorials.config;
	import org.springframework.context.MessageSource;
	import org.springframework.context.annotation.Bean;
	import org.springframework.context.annotation.ComponentScan;
	import org.springframework.context.annotation.Configuration;
	import org.springframework.context.support.ResourceBundleMessageSource;
	import org.springframework.validation.beanvalidation.LocalValidatorFactoryBean;
	import org.springframework.web.servlet.config.annotation.EnableWebMvc;
	import org.springframework.web.servlet.view.InternalResourceViewResolver;
	import org.springframework.web.servlet.view.JstlView;
	@Configuration
	@EnableWebMvc
	@ComponentScan({ "org.junjun.spring.tutorials.web" })
	public class WebConfig {
	/**
	* Register Bean Validator.
	*
	* @return
	*/
	@Bean
	public javax.validation.Validator localValidatorFactoryBean() {
	return new LocalValidatorFactoryBean();
	}
	/**
	* Configure MessageSource to provide internationalized messages
	*
	*/
	@Bean
	public MessageSource messageSource() {
	ResourceBundleMessageSource messageSource = new ResourceBundleMessageSource();
	messageSource.setBasename("messages");
	return messageSource;
	}
	/**
	* Configure View Resolver
	*/
	@Bean
	public InternalResourceViewResolver viewResolver() {
	InternalResourceViewResolver viewResolver = new InternalResourceViewResolver();
	viewResolver.setViewClass(JstlView.class);
	viewResolver.setPrefix("/WEB-INF/jsp/");
	viewResolver.setSuffix(".jsp");
	return viewResolver;
	}
	}

view raw WebConfig.java hosted with ❤ by GitHub

4. POJO

	package org.junjun.spring.tutorials.bean;
	import static org.junjun.spring.tutorials.common.Const.DF_DD_MMM_YYYY;
	import java.io.Serializable;
	import java.util.Date;
	import org.hibernate.validator.constraints.NotEmpty;
	public class ToDoEntity implements Serializable {
	@NotEmpty
	String content;
	Date createdDate;
	public String getContent() {
	return content;
	}
	public void setContent(String content) {
	this.content = content;
	}
	public Date getCreatedDate() {
	return createdDate;
	}
	public String getCreatedDateDisplay() {
	return DF_DD_MMM_YYYY.format(createdDate);
	}
	public void setCreatedDate(Date createdDate) {
	this.createdDate = createdDate;
	}
	}

view raw ToDoEntity.java hosted with ❤ by GitHub

We would make this POJO a JPA entity class in following posts when persistence is introduced.




5. DAO

	package org.junjun.spring.tutorials.dao;
	import java.util.List;
	import org.junjun.spring.tutorials.bean.ToDoEntity;
	public interface ToDoDao {
	List<ToDoEntity> getAll();
	ToDoEntity create(ToDoEntity toDoEntity);
	}

view raw ToDoDao.java hosted with ❤ by GitHub

	package org.junjun.spring.tutorials.dao.impl;
	import java.util.ArrayList;
	import java.util.Date;
	import java.util.List;
	import org.junjun.spring.tutorials.bean.ToDoEntity;
	import org.junjun.spring.tutorials.dao.ToDoDao;
	import org.springframework.stereotype.Repository;
	@Repository
	public class ToDoDaoImpl implements ToDoDao {
	private List<ToDoEntity> list = new ArrayList<>();
	public ToDoDaoImpl() {
	ToDoEntity defaultToDo = new ToDoEntity();
	defaultToDo.setContent("default");
	defaultToDo.setCreatedDate(new Date());
	list.add(defaultToDo);
	}
	@Override
	public List<ToDoEntity> getAll() {
	return list;
	}
	@Override
	public ToDoEntity create(ToDoEntity toDoEntity) {
	list.add(toDoEntity);
	return toDoEntity;
	}
	}

view raw ToDoDaoImpl.java hosted with ❤ by GitHub

We would have DAO talk to database in the following posts.




6.  BUSINESS LOGIC LAYER

	package org.junjun.spring.tutorials.service;
	import java.util.List;
	import org.junjun.spring.tutorials.bean.ToDoEntity;
	public interface ToDoService {
	List<ToDoEntity> getAll();
	ToDoEntity create(ToDoEntity todo);
	}

view raw ToDoService.java hosted with ❤ by GitHub

	package org.junjun.spring.tutorials.service.impl;
	import java.util.Date;
	import java.util.List;
	import org.junjun.spring.tutorials.bean.ToDoEntity;
	import org.junjun.spring.tutorials.dao.ToDoDao;
	import org.junjun.spring.tutorials.service.ToDoService;
	import org.springframework.beans.factory.annotation.Autowired;
	import org.springframework.stereotype.Service;
	@Service
	public class ToDoServiceImpl implements ToDoService {
	@Autowired
	private ToDoDao toDoDao;
	@Override
	public List<ToDoEntity> getAll() {
	return toDoDao.getAll();
	}
	@Override
	public ToDoEntity create(ToDoEntity toDoEntity) {
	toDoEntity.setCreatedDate(new Date());
	return toDoDao.create(toDoEntity);
	}
	}

view raw ToDoServiceImpl.java hosted with ❤ by GitHub

7. TODO CONTROLLER

	package org.junjun.spring.tutorials.web.controller;
	import java.util.List;
	import javax.validation.Valid;
	import org.apache.log4j.Logger;
	import org.junjun.spring.tutorials.bean.ToDoEntity;
	import org.junjun.spring.tutorials.service.ToDoService;
	import org.springframework.beans.factory.annotation.Autowired;
	import org.springframework.stereotype.Controller;
	import org.springframework.ui.Model;
	import org.springframework.validation.BindingResult;
	import org.springframework.validation.ObjectError;
	import org.springframework.web.bind.annotation.ModelAttribute;
	import org.springframework.web.bind.annotation.RequestMapping;
	import org.springframework.web.bind.annotation.RequestMethod;
	@Controller
	@RequestMapping("todo")
	public class ToDoController {
	private static final Logger logger = Logger.getLogger(ToDoController.class);
	@Autowired
	private ToDoService toDoService;
	@RequestMapping(value = "list", method = RequestMethod.GET)
	public String list(Model model) {
	String page = "todo/list";
	List<ToDoEntity> toDoList = toDoService.getAll();
	model.addAttribute("toDoList", toDoList);
	model.addAttribute("newToDo", new ToDoEntity());
	return page;
	}
	@RequestMapping(value = "create", method = RequestMethod.POST)
	public String create(@Valid @ModelAttribute("newToDo") ToDoEntity toDoEntity, BindingResult result, Model model) {
	String page = "todo/list";
	if (result.hasErrors()) {
	for (ObjectError error : result.getAllErrors()) {
	logger.debug(error.getDefaultMessage());
	}
	} else {
	toDoService.create(toDoEntity);
	}
	List<ToDoEntity> toDoList = toDoService.getAll();
	model.addAttribute("toDoList", toDoList);
	model.addAttribute("newToDo", toDoEntity);
	return page;
	}
	@RequestMapping(value = "error", method = RequestMethod.GET)
	public String error(Model model) {
	String page = "todo/list";
	String[] data = new String[] { "1" };
	logger.error(data[2]);
	return page;
	}
	}

view raw ToDoController.java hosted with ❤ by GitHub

1. Container will do bean validation on model attribute that marked with @Valid 
2. BindingResult must be declared right after @Valid




8. EXCEPTION HANDLER

	package org.junjun.spring.tutorials.web.advice;
	import javax.servlet.http.HttpServletRequest;
	import org.springframework.core.annotation.AnnotationUtils;
	import org.springframework.web.bind.annotation.ControllerAdvice;
	import org.springframework.web.bind.annotation.ExceptionHandler;
	import org.springframework.web.bind.annotation.ResponseStatus;
	import org.springframework.web.servlet.ModelAndView;
	import org.springframework.web.servlet.NoHandlerFoundException;
	@ControllerAdvice
	public class ExceptionAdviceController {
	@ExceptionHandler(NoHandlerFoundException.class)
	public String dealWithNoHandlerFoundException(HttpServletRequest httpServletRequest) {
	return "not-found";
	}
	@ExceptionHandler(value = Exception.class)
	public ModelAndView defaultErrorHandler(HttpServletRequest req, Exception e) throws Exception {
	// If the exception is annotated with @ResponseStatus rethrow it and let
	// the framework handle it
	if (AnnotationUtils.findAnnotation(e.getClass(), ResponseStatus.class) != null)
	throw e;
	// Otherwise setup and send the user to a default error-view.
	ModelAndView mav = new ModelAndView();
	mav.addObject("exception", e);
	mav.addObject("url", req.getRequestURL());
	mav.setViewName("error");
	return mav;
	}
	}

view raw ExceptionAdviceController.java hosted with ❤ by GitHub

@ControllerAdvice  is typically used to define ExceptionHandler , InitBinder and ModelAttribute methods that apply to all RequestMapping methods.


9. WEB PAGE

	<%@ page language="java" contentType="text/html; charset=UTF-8"
	pageEncoding="UTF-8"%>
	<%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core"%>
	<%@ taglib prefix="spring" uri="http://www.springframework.org/tags"%>
	<%@ taglib prefix="form" uri="http://www.springframework.org/tags/form"%>
	<!DOCTYPE html>
	<html lang="en">
	<head>
	<meta charset="utf-8">
	<meta http-equiv="X-UA-Compatible" content="IE=edge">
	<meta name="viewport" content="width=device-width, initial-scale=1">
	<meta name="description" content="spring">
	<meta name="keywords" content="spring">
	<title></title>
	<link rel="stylesheet"
	href="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.6/css/bootstrap.min.css">
	</head>
	<body>
	<div class="container" style="padding-top: 10%">
	<div class="row">
	<form:form class="form-horizontal" role="form"
	modelAttribute="newToDo" method="post"
	action="${pageContext.request.contextPath}/todo/create">
	<div class="form-group">
	<div class="col-md-offset-2 col-md-6">
	<form:input id="todoContent" class="form-control" path="content"
	placeholder="" />
	</div>
	<label for="todoContent" class="col-md-4 control-label"
	style="text-align: left;"><spring:bind path="content">
	<c:if test="${status.error}">
	<form:errors path="content" class="text-danger" />
	</c:if>
	</spring:bind></label>
	</div>
	</form:form>
	</div>
	<div class="row">
	<div class="col-md-offset-2 col-md-10">
	<ul>
	<c:forEach items="${toDoList}" var="toDo">
	<li>${toDo.createdDateDisplay}&nbsp;:&nbsp;${toDo.content}</li>
	</c:forEach>
	</ul>
	</div>
	</div>
	</div>
	<script src="http://code.jquery.com/jquery-latest.min.js"></script>
	<script
	src="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.6/js/bootstrap.min.js"></script>
	</body>
	</html>

view raw list.jsp hosted with ❤ by GitHub

	<%@ page language="java" contentType="text/html; charset=UTF-8"
	pageEncoding="UTF-8"%>
	<%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core"%>
	<%@ taglib prefix="spring" uri="http://www.springframework.org/tags"%>
	<%@ taglib prefix="form" uri="http://www.springframework.org/tags/form"%>
	<!DOCTYPE html>
	<html lang="en">
	<head>
	<meta charset="utf-8">
	<meta http-equiv="X-UA-Compatible" content="IE=edge">
	<meta name="viewport" content="width=device-width, initial-scale=1">
	<meta name="description" content="spring">
	<meta name="keywords" content="spring">
	<title></title>
	<link rel="stylesheet"
	href="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.6/css/bootstrap.min.css">
	</head>
	<body>
	<div class="container" style="padding-top: 10%; height: 100%">
	<div class="text-center col-md-12">
	<h1>NOT FOUND</h1>
	</div>
	</div>
	</body>
	</html>

view raw not-found.jsp hosted with ❤ by GitHub

10. Messages for Validation Error

11. TEST

http://localhost:8080/spring-mvc-bean-validation/todo/create

http://localhost:8080/spring-mvc-bean-validation/anything

http://localhost:8080/spring-mvc-bean-validation/todo/error

12. SOURCE CODE

https://github.com/junjun-dachi/spring-tutorials/tree/master/spring-mvc-bean-validation