In this tutorial, I am going to show you the most popular and trending module in Spring Framework that is Spring Boot. By this tutorials you can get to know how to write a Simple Spring Boot Example.

Used Technologies :

• Spring 3.2.3
• Spring Boot 1.5.1
• Java 8
• Maven 3

Spring Boot Example :

Here I am going to implement a basic hello world spring boot example.

Project Structure :

Maven Dependencies :

To make our example as simple as possible, I have placed dependencies in pom.xml what just I want.

<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/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>
<groupId>org.springframework.samples</groupId>
<artifactId>Spring_Boot_Example</artifactId>
<version>0.0.1-SNAPSHOT</version>

<properties>

<!-- Generic properties -->
<java.version>1.8</java.version>
<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
<project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>

<!-- Spring -->
<spring-framework.version>3.2.3.RELEASE</spring-framework.version>

</properties>
<parent>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-parent</artifactId>
<version>1.5.1.RELEASE</version>
</parent>

<dependencies>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency>
</dependencies>
<build>
<plugins>
<plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
</plugin>
</plugins>
</build>
</project>

Create Application Class :

package com.onlinetutorialspoint.spring.boot;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;

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

@SpringBootApplication annotation tells the spring application context, it is an spring boot application. Most of the developers can used to define the spring boot main classes with the @Configuration, @EnableAutoConfiguration and @ComponentScan annotations. Since these annotations are mandatory to every Spring application, the Spring Boot given us an annotation called @SpringBootApplication instead.

Here @Configuration + @EnableAutoConfiguration + @ComponentScan = @SpringBootApplication

Create a Controller Class :

package com.onlinetutorialspoint.spring.boot;

import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

@RestController
public class HelloController {
    @RequestMapping("/")
    public String index() {
        return "Hello World Spring !";
    }
}

Running the Spring Boot Example :

On e of the biggest advantage of Spring boot application is, to run we don’t deploy the application in any server. We can run the above spring boot example as a simple Java standalone application.

Run the main method in Application.java.

If every thing goes well, you can find the below text in your console.

Run it :

Happy Learning 🙂