Web Application using Spring Tool Suite,Gradle and Scala

Step 1: Install Gradle on your windows system.

            Download link: http://gradle.org/ (version 2.2.1)

Set the Path environment variable to: your path\gradle-2.2.1-all\gradle-2.2.1\bin

Step 2: Install Scala on your system.

           Download Link: http://www.scala-lang.org/download/  (version 2.11.4)

As above set the Path environment variable to : C:\Program Files\scala\bin;

Step 3: Install  Spring STS with scala IDE plug in
             Download Link : http://spring.io/tools/sts

Step 4: clone this Hello-World github code in your system

             Link : git clone https://github.com/vaibhavtupe/hello-world

Important files:

build.gradle

Mention your gradle version correctly in this file.
And also mention spring boot application main class file.

buildscript {
    repositories {
     maven { url "http://repo.spring.io/release" }
            mavenCentral()
     mavenLocal()
    }
    dependencies {
        classpath("org.springframework.boot:spring-boot-gradle-plugin:1.1.6.RELEASE")
    }
}

apply plugin: 'java'
apply plugin: 'scala'
apply plugin: 'eclipse'
apply plugin: 'eclipse-wtp'
apply plugin: 'idea'
apply plugin: 'spring-boot'

jar {
    baseName = 'hello'
    version =  '0.1.0'
}

bootRepackage {
    mainClass = 'hello.HelloWebApplication'
}

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

dependencies {
    compile("org.springframework.boot:spring-boot-starter-web:1.2.1.RELEASE")
    testCompile("org.springframework.boot:spring-boot-starter-test")
    compile("org.scala-lang:scala-library:2.11.4")
    compile("org.webjars:bootstrap:3.1.1")
    testCompile("junit:junit")
}

task wrapper(type: Wrapper) {
    gradleVersion = '2.2.1'
}

HelloWebApplication.scala

package hello

import org.springframework.boot.SpringApplication
import org.springframework.context.annotation._
import org.springframework.boot.autoconfigure.EnableAutoConfiguration

/**
 * This object bootstraps Spring Boot web application.
 * Via Gradle: gradle bootRun
 *
 * @author vaibhav
 * @since 1.0
 */

@EnableAutoConfiguration
object HelloWebApplication {

 def main(args: Array[String]) {
    SpringApplication.run(classOf[HelloConfig]);
 }
}

HelloConfig.scala

package hello

import org.springframework.context.annotation.{Configuration, ComponentScan}
import org.springframework.boot.autoconfigure.EnableAutoConfiguration
import org.springframework.boot;
import org.springframework.web.bind.annotation.RequestMapping; 
import org.springframework.web.bind.annotation.ResponseBody; 
import org.springframework.stereotype.Controller; 

/**
 * This config class will trigger Spring @annotation scanning and auto configure Spring context.
 *
 * @author vaibhav
 * @since 1.0
 */
 
@Controller
@Configuration
@EnableAutoConfiguration
@ComponentScan
class HelloConfig {

@RequestMapping(Array("/"))
@ResponseBody
def home(): String = "Hello World!"

}

Step 5 : Go to the cloned directory hello-world/Hello-Scala from command prompt

            Now do 

            gradle build

      After successful build,

       gradle run

Step 6 : Check the browser localhost:8080

Step 7 : Now same thing we can do on AWS EC2 instance using putty,  

              Download and install gradle, scala on EC2 instance

              Do step 4 an step 5 again on EC2 instance.

Step 8 : Now go in your local machine browser and hit the URL

              Your EC2 instance public DNS:8080

You have successfully created simple hello-world web application using spring tool suite and deployed it on Amazon EC2 instance.