First spring boot web application

In this tutorial, we will build our first spring boot web application. Following tools we will be using for the purpose.

1. Java 1.8 or higher version
2. Spring Initializr web tool
3. maven

1. Create a maven project using Spring Initializr web tool

Go to the website https://start.spring.io/ and provide the maven project information like groupId, artifactId, description etc

2. Add Dependency

Click on ‘Add Dependencies’ on right side corner and Type web in there. Add web dependency and click on generate. It will download the project on your local machine.

2. Unzip the project and import into STS

3. Verify pom.xml

Verify your pom.xml. It should contain spring-boot-starter-web dependency

<?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 https://maven.apache.org/xsd/maven-4.0.0.xsd">
	<modelVersion>4.0.0</modelVersion>
	<parent>
		<groupId>org.springframework.boot</groupId>
		<artifactId>spring-boot-starter-parent</artifactId>
		<version>2.6.6</version>
		<relativePath/> <!-- lookup parent from repository -->
	</parent>
	<groupId>com.javatrainingschool</groupId>
	<artifactId>first-spring-boot-web-app</artifactId>
	<version>0.0.1-SNAPSHOT</version>
	<name>first-spring-boot-web-app</name>
	<description>Demo project for Spring Boot</description>
	<properties>
		<java.version>1.8</java.version>
	</properties>
	<dependencies>
		<dependency>
			<groupId>org.springframework.boot</groupId>
			<artifactId>spring-boot-starter-web</artifactId>
		</dependency>

		<dependency>
			<groupId>org.springframework.boot</groupId>
			<artifactId>spring-boot-starter-test</artifactId>
			<scope>test</scope>
		</dependency>
	</dependencies>

	<build>
		<plugins>
			<plugin>
				<groupId>org.springframework.boot</groupId>
				<artifactId>spring-boot-maven-plugin</artifactId>
			</plugin>
		</plugins>
	</build>

</project>

4. Write you web application controller

Create a controller class for this web application. We have @RestController annotation and @RequestMapping annotation. @RestController makes it a rest controller and @RequestMapping maps the request url with the method.

package com.javatrainingschool;

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

@RestController
@RequestMapping("/test")
public class TestingController {
	
	@RequestMapping("/welcome")
	public String welcome() {
		return "Welcome to your first spring boot application";
	}
	
	@RequestMapping("/home")
	public String home() {
		return "This is the home url";
	}

}

5. Locate the spring boot application class with main method

There should be a java file in your project which is annotated with @SpringBootApplication and has main method. This is the entry point for your spring boot application. Right click on it and run the application as a java application.

You will see following output on your console.

As we can see, our web application is up and running on tomcat on port no 8080.

6. Test the application

Since, we have created a rest service as our web application, we can test it by sending a request from the browser. Hit the below url and verify your output.

Test another rest endpoint