Spring 3 MVC hello world example – Annotation

In this tutorial, we will take the previous Maven + Spring MVC XML example, rewrite it to support `@JavaConfig` configuration, no more XML files, and deploy it into a Servlet 3.0+ container, like Tomcat 7 or Jetty 9.Technologies used :- Spring 3.2.13.RELEASE- Maven 3- JDK 1.6- Tomcat 7 or Jetty 9- Eclipse 4.4- Boostrap 3##1. Project StructureDownload the project source code and review the project folder structure :> P.S No more XML files like `web.xml `or any other Spring XML configuration files.##2. Maven###2.1 A `pom.xml` template to quick start a Spring MVC project. To compile this project, we need to add a servlet-api dependency.####pom.xml

<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>com.mkyong</groupId>  <artifactId>spring3-mvc-maven-annotation-hello-world</artifactId>  <packaging>war</packaging>  <version>1.0-SNAPSHOT</version>  <name>spring mvc</name>  <properties>    <jdk.version>1.6</jdk.version>    <spring.version>3.2.13.RELEASE</spring.version>    <jstl.version>1.2</jstl.version>    <servletapi.version>3.1.0</servletapi.version>  </properties>  <dependencies>    <dependency>        <groupId>org.springframework</groupId>        <artifactId>spring-webmvc</artifactId>        <version>${spring.version}</version>    </dependency>    <dependency>        <groupId>javax.servlet</groupId>        <artifactId>jstl</artifactId>        <version>${jstl.version}</version>    </dependency>    <!-- compile only, deployed container will provide this -->    <dependency>        <groupId>javax.servlet</groupId>        <artifactId>javax.servlet-api</artifactId>        <version>${servletapi.version}</version>        <scope>provided</scope>    </dependency>  </dependencies>  <build>    <plugins>    <plugin>        <groupId>org.apache.maven.plugins</groupId>        <artifactId>maven-compiler-plugin</artifactId>        <version>3.3</version>        <configuration>            <source>${jdk.version}</source>            <target>${jdk.version}</target>        </configuration>    </plugin>    <!-- embedded Jetty server, for testing -->    <plugin>        <groupId>org.eclipse.jetty</groupId>        <artifactId>jetty-maven-plugin</artifactId>        <version>9.2.11.v20150529</version>        <configuration>            <scanIntervalSeconds>10</scanIntervalSeconds>            <webApp>                <contextPath>/spring3</contextPath>            </webApp>        </configuration>    </plugin>    <!-- configure Eclipse workspace -->     <plugin>        <groupId>org.apache.maven.plugins</groupId>        <artifactId>maven-eclipse-plugin</artifactId>        <version>2.9</version>        <configuration>            <downloadSources>true</downloadSources>            <downloadJavadocs>true</downloadJavadocs>            <wtpversion>2.0</wtpversion>            <wtpContextName>spring3</wtpContextName>        </configuration>    </plugin>    </plugins>  </build>  </project>

###2.2 To compile this project and make it supports Eclipse IDE.Terminal

$ mvn eclipse:eclipse

##3. Spring Controller###HelloController.java

package com.mkyong.web.controller;import org.springframework.stereotype.Controller;import org.springframework.ui.ModelMap;import org.springframework.web.bind.annotation.PathVariable;import org.springframework.web.bind.annotation.RequestMapping;import org.springframework.web.bind.annotation.RequestMethod;import org.springframework.web.servlet.ModelAndView;@Controllerpublic class HelloController {    @RequestMapping(value = "/", method = RequestMethod.GET)    public String printWelcome(ModelMap model) {        model.addAttribute("message", "Spring 3 MVC Hello World");        return "hello";    }    @RequestMapping(value = "/hello/{name:.+}", method = RequestMethod.GET)    public ModelAndView hello(@PathVariable("name") String name) {        ModelAndView model = new ModelAndView();        model.setViewName("hello");        model.addObject("msg", name);        return model;    }}

##4. JSP ViewsA JSP page to display the value, and include bootstrap css and js.

html4strict

<%@ taglib prefix="spring" uri="http://www.springframework.org/tags"%><%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core"%><!DOCTYPE html><html lang="en"><head><spring:url value="/resources/core/css/hello.css" var="coreCss" /><spring:url value="/resources/core/css/bootstrap.min.css" var="bootstrapCss" /><link href="${bootstrapCss}" rel="stylesheet" /><link href="${coreCss}" rel="stylesheet" /></head><nav class="navbar navbar-inverse navbar-fixed-top">  <div class="container">    <div class="navbar-header">        <a class="navbar-brand" href="#">Spring 3 MVC Project @JavaConfig</a>    </div>  </div></nav><div class="jumbotron">  <div class="container">    <h1>${title}</h1>    <p>        <c:if test="${not empty name}">            Hello ${name}        </c:if>        <c:if test="${empty name}">            Welcome Welcome!        </c:if>    </p>    <p>        <a class="btn btn-primary btn-lg" href="#" role="button">Learn more</a>    </p>    </div></div><div class="container">  <div class="row">    <div class="col-md-4">        <h2>Heading</h2>        <p>ABC</p>        <p>            <a class="btn btn-default" href="#" role="button">View details</a>        </p>    </div>    <div class="col-md-4">        <h2>Heading</h2>        <p>ABC</p>        <p>            <a class="btn btn-default" href="#" role="button">View details</a>        </p>    </div>    <div class="col-md-4">        <h2>Heading</h2>        <p>ABC</p>        <p>            <a class="btn btn-default" href="#" role="button">View details</a>        </p>    </div>  </div>  <hr />  <footer>    <p>© Mkyong.com 2015</p>  </footer></div><spring:url value="/resources/core/css/hello.js" var="coreJs" /><spring:url value="/resources/core/css/bootstrap.min.js" var="bootstrapJs" /><script src="${coreJs}"></script><script src="${bootstrapJs}"></script><script src="https://ajax.googleapis.com/ajax/libs/jquery/1.11.2/jquery.min.js"></script></body></html>

5. Spring @JavaConfig

SpringWebConfig.java

package com.mkyong.config;import org.springframework.context.annotation.Bean;import org.springframework.context.annotation.ComponentScan;import org.springframework.context.annotation.Configuration;import org.springframework.web.servlet.config.annotation.EnableWebMvc;import org.springframework.web.servlet.config.annotation.ResourceHandlerRegistry;import org.springframework.web.servlet.config.annotation.WebMvcConfigurerAdapter;import org.springframework.web.servlet.view.InternalResourceViewResolver;import org.springframework.web.servlet.view.JstlView;@EnableWebMvc //mvc:annotation-driven@Configuration@ComponentScan({ "com.mkyong.web" })public class SpringWebConfig extends WebMvcConfigurerAdapter {    @Override    public void addResourceHandlers(ResourceHandlerRegistry registry) {        registry.addResourceHandler("/resources/**").addResourceLocations("/resources/");    }    @Bean    public InternalResourceViewResolver viewResolver() {        InternalResourceViewResolver viewResolver = new InternalResourceViewResolver();        viewResolver.setViewClass(JstlView.class);        viewResolver.setPrefix("/WEB-INF/views/jsp/");        viewResolver.setSuffix(".jsp");        return viewResolver;    }}

XML equivalent.

<beans xmlns="http://www.springframework.org/schema/beans"    xmlns:context="http://www.springframework.org/schema/context"    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"    xmlns:mvc="http://www.springframework.org/schema/mvc"    xsi:schemaLocation="        http://www.springframework.org/schema/beans             http://www.springframework.org/schema/beans/spring-beans-3.2.xsd        http://www.springframework.org/schema/mvc         http://www.springframework.org/schema/mvc/spring-mvc-3.2.xsd        http://www.springframework.org/schema/context         http://www.springframework.org/schema/context/spring-context-3.2.xsd">    <context:component-scan base-package="com.mkyong.web" />    <bean        class="org.springframework.web.servlet.view.InternalResourceViewResolver">        <property name="prefix">            <value>/WEB-INF/views/jsp/</value>        </property>        <property name="suffix">            <value>.jsp</value>        </property>    </bean>    <mvc:resources mapping="/resources/**" location="/resources/" />    <mvc:annotation-driven /></beans>

6. Servlet 3.0+ Container

Create a ServletInitializer class by extending AbstractAnnotationConfigDispatcherServletInitializer, the Servlet 3.0+ container will pick up this class and run it automatically. This is the replacement for web.xml.

MyWebInitializer.java

package com.mkyong.servlet3;import org.springframework.web.servlet.support.AbstractAnnotationConfigDispatcherServletInitializer;import com.mkyong.config.SpringWebConfig;public class MyWebInitializer extends        AbstractAnnotationConfigDispatcherServletInitializer {    @Override    protected Class<?>[] getServletConfigClasses() {        return new Class[] { SpringWebConfig.class };    }    @Override    protected String[] getServletMappings() {        return new String[] { "/" };    }    @Override    protected Class<?>[] getRootConfigClasses() {        return null;    }}

7. Demo

Download the project and run it with the embedded Jetty container.
Terminal

$ mvn jetty:run

URL : http://localhost:8080/spring3

URL : http://localhost:8080/spring3/hello/mkyong