라이브스마트

Hello! In this course, we will learn how to develop backend applications using Spring Boot. Spring Boot is a lightweight framework based on the Spring Framework that helps you quickly develop production-grade applications. In this article, we will explain in detail how to set up the development environment and create a project.

1. Setting Up the Development Environment

Before starting a Spring Boot project, you need to set up the following development environment.

1.1. Install JDK

Since Spring Boot is based on Java, you need to install the JDK (Java Development Kit). The JDK is a tool that compiles and runs Java source code.

• JDK Download: [Oracle JDK Download Page](https://www.oracle.com/java/technologies/javase-jdk11-downloads.html) or [OpenJDK Download Page](https://openjdk.java.net/install/)
• After installation, check if it was successful by running the command java -version in the terminal.

1.2. Install an IDE

You need to use an IDE (Integrated Development Environment) to write code. There are various IDEs like IntelliJ IDEA, Eclipse, and VSCode, but in this course, we recommend IntelliJ IDEA.

• IntelliJ IDEA Download: [JetBrains Official Website](https://www.jetbrains.com/idea/download/)
• After installation, you can create a new Spring Boot project through the ‘Create New Project’ menu.

1.3. Install Maven

Spring Boot uses Maven to manage dependencies. You can easily add the necessary libraries by installing Maven.

• Maven Download: [Maven Official Website](https://maven.apache.org/download.cgi)
• After installation, check if it is completed by running the command mvn -v.

2. Creating a Project

Now that the development environment is fully prepared, the next step is to create a Spring Boot project.

2.1. Using Spring Initializr

Spring Initializr is a web-based tool that allows you to easily create Spring Boot projects. Follow the steps below to create a project.

• Open [Spring Initializr](https://start.spring.io/) in your browser.
• Select Project: Choose either Maven Project or Gradle Project.
• Select Language: Choose Java.
• Select Spring Boot Version: Choose the latest stable version (e.g., 2.6.6).
• Enter Project Metadata: You need to fill in the following fields.
• Group: com.example
• Artifact: demo
• Name: demo
• Description: Demo project for Spring Boot
• Package name: com.example.demo
• Packaging: Choose Jar.
• Java: Select the version that matches your JDK version (e.g., 11).
• Add Dependencies: Select the libraries you need for your project. For example, you can add Spring Web, Spring Data JPA, H2 Database, etc.
• Click the Generate button to create the project and download the ZIP file.

2.2. Opening the Project in IntelliJ

After extracting the downloaded ZIP file, open IntelliJ IDEA and follow the steps below.

• Select ‘File’ -> ‘Open’ and choose the extracted project folder.
• IntelliJ will recognize Maven and download the necessary libraries. Once this process is complete, the project structure will be ready.

2.3. Writing Application Code

Now let’s create a simple Spring Boot application. Open the src/main/java/com/example/demo/DemoApplication.java file and enter the following code.

Hello! In this blog, we will learn about Spring Boot backend development. Backend development is responsible for data processing and business logic in web applications, and various tools and frameworks are needed to perform these functions efficiently. Among them, Spring Boot is a Java-based framework that allows for rapid and convenient development. This article will provide detailed instructions on how to set up the development environment necessary for using Spring Boot, particularly how to install and configure IntelliJ in a Windows environment.

1. What is Spring Boot?

Spring Boot is an extension of the Spring framework designed for rapid application development. It reduces complex XML configurations and provides minimal settings required to run the application. Spring Boot supports embedded servers (e.g., Tomcat, Jetty), making it easy to deploy and run applications.

2. Features of Spring Boot

• Auto Configuration: Spring Boot automatically performs basic configuration, helping developers use it easily even if they are not familiar with it.
• Standalone Application: Spring Boot applications are packaged with an embedded server and can run independently.
• Starter Dependencies: It provides starter packages to quickly add required dependencies.
• Actuator: It offers functionality to monitor the state and performance of the application.

3. Setting Up the Development Environment

To use Spring Boot, you will need the Java Development Kit (JDK), an IDE like IntelliJ IDEA, and Spring Initializr. This section will explain how to install and configure IntelliJ on Windows.

3.1 Installing JDK

• Download JDK: Download the JDK from Oracle’s official website or OpenJDK.
• Installation: Run the downloaded file to install it. After installation, set the environment variable to specify `JAVA_HOME` as the installation directory of the JDK.
• Verification: Open a command prompt and enter the command java -version to verify the installation was completed successfully.

3.2 Installing IntelliJ IDEA

IntelliJ IDEA is a Java IDE provided by JetBrains, optimized for Spring Boot development. Let’s follow the steps to install IntelliJ.

Step 1: Download IntelliJ

• Visit JetBrains’ official website (https://www.jetbrains.com/idea/download/) and download the free community version.

Step 2: Installation

• Run the downloaded installation file.
• Follow the installation wizard’s instructions. You can choose useful options like “Create Desktop Shortcut” during the installation options.

Step 3: Initial Setup

• Once the installation is complete, launch IntelliJ.
• Select “Do not import settings” to use the default configuration.
• Choose the theme and other user settings.

Step 4: Installing Plugins

• You can install Spring-related plugins from IntelliJ’s plugin marketplace. Go to “File” -> “Settings” -> “Plugins” menu, search for necessary plugins in the “Marketplace” and install them.

4. Creating a Project Using Spring Initializr

After installing IntelliJ, let’s learn how to create a Spring Boot project. Using Spring Initializr allows you to easily create a project template.

Step 1: Create a New Project

• Run IntelliJ and select “New Project.”
• Select “Spring Initializr” on the left and click “Next.”

Step 2: Enter Project Metadata

• Group: com.example
• Artifact: demo
• Name: demo
• Package Name: com.example.demo
• Packaging: Selectable (jar or war)
• Java Version: Choose the JDK version you will use.

Step 3: Add Dependencies

• You can select “Spring Web” for web development and “Spring Data JPA” for database connectivity.
• After adding dependencies, click “Next” and then “Finish” to create the project.

5. Basic Structure of a Spring Boot Project

Let’s explain the basic directory structure of the generated project. A Spring Boot project has the following structure:

com
└── example
    └── demo
        ├── DemoApplication.java
        ├── controller
        ├── service
        └── repository

• DemoApplication.java: This is the entry point of the Spring Boot application. It performs Spring configuration and component scanning via the @SpringBootApplication annotation.
• controller: Contains controller classes responsible for handling web requests.
• service: Contains service classes that handle business logic.
• repository: Contains repository classes for database access.

6. Creating Your First REST API

Now let’s create a simple REST API that returns user information.

Step 1: Create a Controller

package com.example.demo.controller;

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

@RestController
public class UserController {
    
    @GetMapping("/users")
    public String getUsers() {
        return "User List";
    }
}

Step 2: Run the Application

• Run the DemoApplication.java file in IntelliJ to start the application.
• Access http://localhost:8080/users in a web browser to verify the result.

7. Conclusion

In this article, we covered how to set up a backend development environment using Spring Boot, how to install IntelliJ, and how to create your first REST API. Spring Boot provides powerful features and flexibility, so I encourage you to continue exploring its various functionalities. The next article will discuss how to integrate a database and create more complex APIs. I hope you learn a lot through consistent practice and hands-on experience.

Thank you!

Spring Boot is a Java-based framework that helps you build RESTful web services quickly and easily. In this course, you will learn backend development using Spring Boot and how to install IntelliJ IDEA for development in a macOS environment. This course covers content from basics to advanced topics.

1. Understanding Spring Boot

Spring Boot is built on top of the Spring framework, and it helps to set up and configure your projects more quickly than traditional Spring projects. This allows developers to write only the code they need, reducing the time spent on repetitive configurations. Spring Boot can flexibly respond to various deployment structures, such as cloud environments and microservices architectures.

1.1 Features of Spring Boot

• Auto Configuration: Automatically handles common configurations, allowing developers to focus on business logic.
• Starter Dependency Management: Easily manages necessary libraries through Maven or Gradle.
• Executor Support: Facilitates asynchronous processing to enhance performance and scalability.
• Prebuilt Aspects: Quickly develop using pre-made templates.

2. Setting Up the Development Environment

Now we will set up the environment needed to develop a Spring Boot project. Follow the steps below to install IntelliJ IDEA on macOS and set up the JDK.

2.1 Installing the JDK

To develop with Spring Boot, you need the Java Development Kit (JDK). On macOS, you can easily install the JDK via Homebrew.

brew install openjdk@11

Once the installation is complete, set the system environment variables. This will allow the system to recognize the path to the JDK.

echo 'export JAVA_HOME="$(brew --prefix openjdk@11)"' >> ~/.zshrc

source ~/.zshrc

2.2 Installing IntelliJ IDEA

IntelliJ IDEA is one of the most popular Java IDEs. Install it on macOS following the steps below.

2.2.1 Installing via Homebrew

If you already use Homebrew, you can install IntelliJ IDEA Community Edition with the following command.

brew install --cask intellij-idea-community

2.2.2 Direct Download

You can also download and install it directly. Download the IntelliJ IDEA Community Edition from JetBrains’ official website and install it. Once installed, run the program and follow the setup wizard to configure the basic environment.

2.3 Configuring IntelliJ IDEA

When you first start IntelliJ IDEA, you need to install the required plugins and configure the environment. The plugin for Spring Boot is built into the IDE, but you can also install additional plugins if needed.

1. Run IntelliJ IDEA.
2. In the main menu, select File > Settings (for macOS, IntelliJ IDEA > Preferences).
3. Navigate to the Plugins tab and search for and install any necessary additional plugins.

3. Creating a Spring Boot Project

Now let’s create a Spring Boot project in IntelliJ IDEA. This will enable you to start backend development in earnest.

3.1 Creating a New Project

1. Click New Project in IntelliJ IDEA.
2. Select Spring Initializr from the left menu.
3. Set the Project SDK to JDK 11.
4. Click the Next button to proceed to the next step.
5. Configure the Group and Artifact. For example, set Group to com.example and Artifact to demo.
6. Select the necessary libraries under Dependencies. For example, you can choose Spring Web, Spring Data JPA, etc.
7. Click Finish to create the project.

3.2 Understanding Project Structure

Once the project is created, you need to understand the basic structure of Spring Boot. Typically, the generated project has the following directory structure:

• src/main/java: The directory where the Java code resides.
• src/main/resources: The directory containing configuration files (yml, properties) and static resources.
• src/test/java: The directory where the test code resides.

3.3 Modifying Basic Configuration Files

You can adjust basic settings by modifying the application.properties or application.yml file in the project root directory. Configure database connection information, server ports, etc.

4. Creating Your First Controller

Now let’s create a simple RESTful API to verify that the Spring Boot application is functioning.

4.1 Creating a Hello Controller

package com.example.demo.controller;

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

@RestController
public class HelloController {

    @GetMapping("/hello")
    public String hello() {
        return "Hello, Spring Boot!";
    }
}

4.2 Running the Application

After writing the controller, start the application by running the main application class. You can build and run the project by executing the following command in the terminal.

./mvnw spring-boot:run

In your web browser, enter http://localhost:8080/hello to see the message “Hello, Spring Boot!”.

5. Conclusion

Through this course, you learned the basic concepts of Spring Boot, how to install IntelliJ IDEA on macOS, and how to build a simple RESTful API. You gained an understanding of the advantages and strengths of Spring Boot, laying the groundwork for using it in real projects. The next steps should include learning about database integration, security and authentication, testing, and deployment methodologies.

6. References

Please explore the resources below for more in-depth study.

• Official Spring Boot Documentation
• Java SE 11 API Documentation
• Official IntelliJ IDEA Site

Spring Boot is a powerful framework for building modern web applications and services. In this course, we will delve into the basic setup for backend development using Spring Boot and some handy shortcuts to enhance development convenience. First, let’s briefly look at the features of Spring Boot.

1. Features of Spring Boot

Spring Boot simplifies the configuration and setup of the Spring framework, helping developers focus on business logic. Here are the main features of Spring Boot:

• Auto Configuration: Spring Boot automatically handles the necessary configurations for the application.
• Embedded Server: Applications can be easily run via an embedded server without needing to install a separate server.
• Dependency Management: Required library dependencies can be simply managed through the POM file.
• Production-Ready Features: Offers various features for monitoring, metric collection, and more.

2. Setting Up the Development Environment

To start development using Spring Boot, you need to set up an appropriate development environment. The following describes the necessary steps.

2.1 Installing JDK

To use Spring Boot, you must first install the Java Development Kit (JDK). The JDK is a tool that helps you develop Java applications. It is advisable to install version 11 or higher.

java -version

2.2 Choosing an IDE

The most commonly used Integrated Development Environments (IDEs) for Spring Boot development include:

• IntelliJ IDEA: An IDE that offers powerful features and convenience, optimized for Spring Boot development.
• Eclipse: An IDE with a wide array of plugins and ecosystem.
• VSCode: A lightweight, fast editor that supports various programming languages.

2.3 Initializing Spring Boot

To start a Spring Boot project, you can generate a project using Spring Initializr. You can access it through the link below:

Spring Initializr

Fill in the metadata in the project settings and select the necessary dependencies:

• Project: Maven Project
• Language: Java
• Spring Boot: Select the desired version
• Dependencies: Spring Web, Spring Data JPA, H2 Database, Lombok, etc.

2.4 Managing Dependencies

Open the POM file of the generated project and add the necessary dependencies. Spring Boot’s dependency management features allow you to manage libraries easily.

3. Handy Shortcuts to Enhance Development Convenience and Speed

Let’s explore shortcuts that can be useful in the IDE while developing. These shortcuts will greatly enhance the convenience and productivity of your development environment.

3.1 IntelliJ IDEA Shortcuts

• Code Completion: Ctrl + Space – Provides automatic code completion.
• Code Formatting: Ctrl + Alt + L – Automatically arranges the code.
• Commenting: Ctrl + / – Comments or uncomments the selected code.
• Finding Methods: Ctrl + F12 – Shows the list of methods in the class.
• Search Everything: Shift + Shift – Allows searching for files, classes, symbols, etc.

3.2 Eclipse Shortcuts

• Code Completion: Ctrl + Space – Uses the auto code completion feature.
• Adding Comments: Ctrl + / – Adds a single-line comment.
• Finding Errors: Ctrl + . – Finds any occurring errors.
• Code Cleanup: Ctrl + Shift + F – Applies code formatting.

3.3 VSCode Shortcuts

• Code Completion: Ctrl + Space – Suggests code snippets and completions.
• File Navigation: Ctrl + P – Quickly performs file search.
• Commenting: Ctrl + / – Comments out the selected lines of code.
• Format Entire Code: Shift + Alt + F – Formats all the code.

4. Conclusion

Backend development using Spring Boot maximizes development convenience due to its various advantages and shortcuts. With the right setup of your development environment and useful shortcuts, you will be able to write code faster and more efficiently. As more advanced development environments and tools emerge, continue to learn and apply them.