Springboot Web Hello World with a Java & Pom.xml file

This blog presents instructions on how to quickly get started with Springboot Hello World with just one Java file and a Pom.xml.

Before getting set up with files, make sure you have installed and configured following

• Java; Setup Java_Home as it is required by maven
• Maven; Maven would be used to package our app.

Java Code Sample

Following is the code for Java file. Make sure to create hello/HelloController.java file within src/main/java. This is required for maven to package it correctly.

package hello;

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

import org.springframework.boot.*;
import org.springframework.boot.autoconfigure.*;
import org.springframework.web.bind.annotation.*;

@RestController
@SpringBootApplication
public class HelloController {

    @RequestMapping("/")
    String home() {
        return "Hello World!";
    }

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

}

Code Sample for POM.xml

Following is the code for pom.xml. Make sure to put pom.xml at the topmost level (along side src folder)

<?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/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>

    <groupId>hello</groupId>
    <artifactId>SpringBootSampleWeb</artifactId>
    <version>0.0.1</version>
 <properties>
     <!-- The main class to start by executing java -jar -->
     <start-class>hello.HelloController</start-class>
 </properties>
    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>1.4.0.RELEASE</version>
    </parent>

    <!-- Additional lines to be added here... -->
    <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>

Package and Run the App

Once you have created the file, execute the following command to run the code:

mvn package
java -jar target/SpringBootSampleWeb-0.0.1.jar