Spring Boot: Fast MVC start

Spring-Boot-MVC-Gradle

I planned to write article about Spring Boot more than a year ago. Finally I have a time and inspiration for this. So prepare yourself for 10 – 15 minutes of high quality Spring tutorial. I’m going to demonstrate Spring Boot basics with Gradle and embedded Tomcat. I use Intellij IDEA instead of Eclipse but this shouldn’t be a problem for those of you who used to Eclipse.

Introduction to Spring Boot

What’s my goal? I want to develop something very similar to on of my previous tutorials about Spring and Java configurations. It’s a good exercise to compare two different approaches for Spring development.
No doubt, most of you know what is the main aim of Spring Boot. For the rest of readers I want to say that Spring Boot makes developers happier because it takes care of configurations meanwhile developer can focus on code production. For more details read official reference.

Gradle build file

Spring-Boot-Project

For managing dependencies and build of the project I use Gradle. Here is how build.gradle file looks:

buildscript {
    repositories {
        //Required repos
        mavenCentral()
        maven { url "http://repo.spring.io/snapshot" }
        maven { url "http://repo.spring.io/milestone" }
    }
    dependencies {
        //Required dependency for spring-boot plugin
        classpath 'org.springframework.boot:spring-boot-gradle-plugin:1.1.2.BUILD-SNAPSHOT'
    }
}

apply plugin: 'java'
apply plugin: 'war'
apply plugin: 'spring-boot'

war {
    baseName = 'companies'
    version =  '0.1'
}

repositories {
    mavenCentral()
    maven { url "http://repo.spring.io/snapshot" }
    maven { url "http://repo.spring.io/milestone" }
}

dependencies {
    compile 'org.springframework.boot:spring-boot-starter-web'
    //Required dependency for JSP
    providedRuntime 'org.apache.tomcat.embed:tomcat-embed-jasper'
}

If you are new to Gradle, I recommend you to read about it somewhere else, e.g. on official site. It’s really nice and practical tool. It can do everything what Maven do, but without XML =)

Spring Boot initialization

Now we can set up Spring Boot on java code level.

package com.companies;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.EnableAutoConfiguration;
import org.springframework.context.annotation.ComponentScan;
import org.springframework.context.annotation.Configuration;

@Configuration
@ComponentScan
@EnableAutoConfiguration
public class CompanyApplication {

    public static void main(String[] args) {
        SpringApplication.run(CompanyApplication.class, args);
    }

}

That’s it, now you can start develop your business logic. Just kidding, we need to put some extra configs related to view resolving.

package com.companies.config;

import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.web.servlet.config.annotation.DefaultServletHandlerConfigurer;
import org.springframework.web.servlet.config.annotation.EnableWebMvc;
import org.springframework.web.servlet.config.annotation.WebMvcConfigurerAdapter;
import org.springframework.web.servlet.view.InternalResourceViewResolver;

@Configuration
@EnableWebMvc
public class WebMvcConfig extends WebMvcConfigurerAdapter{

    @Override
    public void configureDefaultServletHandling(DefaultServletHandlerConfigurer configurer) {
        configurer.enable();
    }

    @Bean
    public InternalResourceViewResolver viewResolver() {
        InternalResourceViewResolver resolver = new InternalResourceViewResolver();
        resolver.setPrefix("WEB-INF/pages/");
        resolver.setSuffix(".jsp");
        return resolver;
    }

}

After you created the class published above, you can go ahead with controller development.

Controller & View

package com.companies.controller;

import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.servlet.ModelAndView;

@Controller
public class HelloWorldController {

    @RequestMapping(value = "/hello", method = RequestMethod.GET)
    public ModelAndView hello() {
        ModelAndView mav = new ModelAndView();
        mav.setViewName("hello");
        
        String str = "Hello World!";
        mav.addObject("message", str);

        return mav;
    }

}

And corresponding view hello.jsp for the controller:

<html>
<head>
    <title>Hello world page</title>
</head>
<body>
    <h1>${message}</h1>
</body>
</html>

I hope it wan’t hard to repeat all these steps.

Run Spring Boot application

The last thing which we have to do in this tutorial is launch of the application. Hence I use Gradle, and in our build.gradle file I specified that the application need to be package as WAR file – I need to run build and run war file.
Here is how it looks like in IDEA:

spring-boot-run

Result you can see here localhost:8080/hello

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  • Rishish Dixit

    I am getting following error everytime I run…Any idea why??

    INFO: Deploying configuration descriptor C:workdevsetupapache-tomcat-7.0.56confCatalinalocalhostMobileApp.xml

    Nov 15, 2014 12:51:35 PM org.apache.catalina.startup.HostConfig deployDescriptor

    WARNING: A docBase C:workdevsetupapache-tomcat-7.0.56webappsMobileApp inside the host appBase has been specified, and will be ignored

    Nov 15, 2014 12:51:35 PM org.apache.catalina.startup.SetContextPropertiesRule begin

    WARNING: [SetContextPropertiesRule]{Context} Setting property ‘source’ to ‘org.eclipse.jst.jee.server:MobileApp’ did not find a matching property.

    Nov 15, 2014 12:51:37 PM org.apache.tomcat.websocket.server.WsSci onStartup