How to Setup Environment for Spring Boot 3

• Java 17 or later installed on your system.
• Maven 3.5+ installed on your system.
• IntelliJ IDEA installed on your system.

• Go to Spring Initializr website
• Select Maven Project as the project type, java as the language, and 3.0.0+ as the Spring boot version (Do not choose SNAPSHOT version)
• Enter the group, artifact, name, and description of your project. For example, com.example as the group, demo as the artifact, spring-boot-3-demo as the name, and Demo project for Spring Boot 3 as the description.
• Select the dependencies you want to add to your project. For this blog, we will only add the Spring Web dependency, which provides the web development features for Spring Boot.
• Click on the Generate button to download the project as a zip file.
• Extract the zip file to your preferred location.

You have now created a Spring Boot 3 project with Maven and Spring Web dependency.

To import the project into IntelliJ IDEA, follow these steps:

• Open IntelliJ IDEA and select File -> Open.
• Navigate to the folder where you extracted the project and select the pom.xml file.
• Click on the Open as Project button to import the project as a Maven project.
• Wait for IntelliJ IDEA to sync the project and download the dependencies.

You have now imported the project into IntelliJ IDEA and ready to start coding.

• Open the src/main/java/com/example/demo/DemoApplication.java file, which is the main class of the project. This class is annotated with @SpringBootApplication, which enables the auto-configuration and component scanning features of Spring Boot.
• Create a new class called FirstController in the same package as the main class. This class will be a web controller that handles the HTTP requests to the /hello endpoint. Annotate this class with @RestController, which indicates that this class is a web controller that returns the data as JSON. Also, import the org.springframework.web.bind.annotation.* package.
• Create a method called hello in the FirstController class. This method will return a simple greeting message as a string. Annotate this method with @GetMapping(“/hello”), which indicates that this method handles the GET requests to the /hello endpoint. Also, add a parameter called name of type String to this method. Annotate this parameter with @RequestParam, which indicates that this parameter is a query parameter in the request URL. For example, http://localhost:8080/hello?name=John. Set the default value of this parameter to World using the defaultValue attribute of the @RequestParam annotation.

package com.example.demo;

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

@RestController
public class FirstController {

    @GetMapping("/hello")
    public String hello(@RequestParam(defaultValue = "World") String name) {
        return "Hello, " + name + "!";
    }
}

You have now created a simple web controller that returns a greeting message based on the query parameter.

To run the application locally,

• Right-click on the DemoApplication class in the project explorer and select Run ‘DemoApplication’. This will start the Spring Boot application on the default port 8080.
• Open your browser and go to http://localhost:8080/hello. You should see the message Hello, World! on the screen.
• Try changing the query parameter to your name, such as [http://localhost:8080/hello?name=John]. You should see the message Hello, John! on the screen.
• You have now run the application locally and tested the web controller.

• https://www.baeldung.com/spring-boot-properties-env-variables
• https://spring.io/guides/gs/spring-boot/
• https://dev.to/lohrran/spring-boot-development-environment-37d7
• https://github.com/spring-guides/gs-spring-boot.git