Math API

A Spring Boot API that provides basic Information about yourself.

Example Requests

Request URL	Response
/api/info	{ "email": "YourEmail@email.com", "current_datetime": "2025-...}

Project Structure

├── src/
│ ├── main/
│ │ ├── java/com/example/apibasic/
│ │ │ ├── ApiResponse.java
│ │ │ ├── CorsConfig.java
│ │ │ ├── ErrorResponse.java
│ │ │ ├── ApiController.java
│ │ │ ├── NumberService.java
│ │ │ └── ApiApiApplication.java
│ │ └── resources/
│ │ ├── application.properties
│ │ └── static/
│ │ └── templates/
│ └── test/
│ └── java/com/example/apibasic/
│ └── MathApiApplicationTests.java
├── pom.xml
└── README.md

How to Set Up the Project

1. Download and Install IntelliJ IDEA CE:

   • Install the latest version of IntelliJ IDEA CE (Community Edition).

2. Create the Spring Boot Project:

   • Go to start.spring.io.
   • Configure the project:
     • Project: Maven
     • Language: Java
     • Spring Boot: 3.4.2
     • Group: com.example
     • Artifact: apibasic
     • Description: Demo Project for Spring Boot
     • Package Name: com.yourDomainName.apibasic
     • Packaging: Jar
     • Java: 17
     • Dependencies: Spring Web, Spring Boot DevTools, Lombok
   • Click Generate to download the project.

3. Open the Project in IntelliJ IDEA:

   • Extract the downloaded ZIP file.
   • Open IntelliJ IDEA and select Open.
   • Navigate to the extracted folder and open it.

4. Create the Required Java Files:

   • Inside src/main/java/com/example/apibasic, create the following files:
     • ApiResponse.java
     • CorsConfig.java
     • ErrorResponse.java
     • ApiController.java
     • ApiService.java
     • ApiApiApplication

ApiResponse.javacode:

package com.example.apibasic;


public class ApiResponse {
    private String email;
    private String current_datetime;
    private String github_url;

    public ApiResponse(String email, String current_datetime, String github_url) {
        this.email = email;
        this.current_datetime = current_datetime;
        this.github_url = github_url;
    }

    // Getters and Setters
    public String getEmail() {
        return email;
    }

    public void setEmail(String email) {
        this.email = email;
    }

    public String getCurrent_datetime() {
        return current_datetime;
    }

    public void setCurrent_datetime(String current_datetime) {
        this.current_datetime = current_datetime;
    }

    public String getGithub_url() {
        return github_url;
    }

    public void setGithub_url(String github_url) {
        this.github_url = github_url;
    }
}

CorsConfig.java code:

package com.example.apibasic;

import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.web.servlet.config.annotation.CorsRegistry;
import org.springframework.web.servlet.config.annotation.WebMvcConfigurer;

@Configuration
public class CorsConfig {

    @Bean
    public WebMvcConfigurer corsConfigurer() {
        return new WebMvcConfigurer() {
            @Override
            public void addCorsMappings(CorsRegistry registry) {
                registry.addMapping("/**")
                        .allowedOrigins("*")
                        .allowedMethods("GET", "POST", "PUT", "DELETE")
                        .allowedHeaders("*");
            }
        };
    }
}

ApiController.java code:

package com.example.apibasic;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.http.ResponseEntity;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

@RestController
@RequestMapping("/api")
public class ApiController {

    @Autowired
    private ApiService apiService;

    @GetMapping("/info")
    public ResponseEntity<ApiResponse> getInfo() {
        ApiResponse response = apiService.getApiResponse();
        return ResponseEntity.ok(response);
    }
}

ApiService.java code:

package com.example.apibasic;

import org.springframework.stereotype.Service;

import java.time.Instant;

@Service
public class ApiService {

    public ApiResponse getApiResponse() {
        String email = "Youremail@email.com";
        String currentDatetime = Instant.now().toString(); // ISO 8601 format
        String githubUrl = "https://github.com/yourgithubUsername/apibasic";

        return new ApiResponse(email, currentDatetime, githubUrl);
    }
}

ApibasicApplication code:

package com.example.apibasic;

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

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

5. Fix Lombok Error:

   • Open pom.xml and add the Lombok dependency:

     <dependency>
         <groupId>org.projectlombok</groupId>
         <artifactId>lombok</artifactId>
         <version>1.18.30</version>
         <scope>provided</scope>
     </dependency>

   • Reload Maven dependencies (View > Tool Windows > Maven > Reload).
   • Install the Lombok plugin in IntelliJ IDEA (File > Settings > Plugins).
   • Enable annotation processing (File > Settings > Build, Execution, Deployment > Compiler > Annotation Processors).

6. Run the Application:

   • Open ApiApplication.java and click the green Run button.
   • The application will start on http://localhost:8080.

7. Test the API:

   • Use Postman to send a GET request to:

     http://localhost:8080/api/info
     

   • Example response:

     json
     {
     

   "email": "youremail@email.com", "current_datetime": "2025-02-05T19:23:14.647210Z", "github_url": "https://github.com/yourUsername/apibasic" }

8. Deploy to AWS EC2:

9. Launch an EC2 Instance

• Go to the AWS EC2 console.
• Click Launch Instance.
• Choose an Amazon Machine Image (AMI):
  • Ubuntu 22.04 LTS or Amazon Linux 2023.
• Choose an Instance Type:
  • t2.micro (Free tier) or t3.small (better performance).
• Configure Security Group:
  • Allow HTTP (80), HTTPS (443), and SSH (22).
• Set Authentication:
  • Use a key pair for SSH access (download the .pem file).
• Click Launch.

2. Connect to EC2 via SSH
   ssh -i your-key.pem ubuntu@your-ec2-public-ip For Windows, use PuTTY with the .pem file.

3. Update EC2

sudo apt update && sudo apt upgrade -y

4. Install OpenJDK 17

sudo apt install openjdk-17-jdk -y

verify the installation java -version

Set Java 17 as default: sudo update-alternatives --config java

Verify again: java -version

5 Set JAVA_HOME

echo 'export JAVA_HOME=/usr/lib/jvm/java-17-openjdk-amd64' | sudo tee -a /etc/environment
echo 'export PATH=$JAVA_HOME/bin:$PATH' | sudo tee -a /etc/environment
source /etc/environment

Verify: echo $JAVA_HOME

Expected output : /usr/lib/jvm/java-17-openjdk-amd64

6 Check if Maven is also installed well and has no error: mvn -version

7 Upload Your Porject to EC2 There are multiple ways to upload your project. If using GitHub, push your project to a repository, then clone it on EC2:

git clone <repository-url>

8 Build and Run Your Project

cd ~/apibasic
mvn clean package
mvn spring-boot:run

9 Test Your API

curl http://your-ec2-public-ip:8080/api/info

9. Configure Your Domain in Route 53:

If your domain is example.com, follow these steps:

1 Add an A Record in Route 53

• Go to AWS Route 53.
• Select your domain (example.com).
• Click Create Record.

Set the following:

• Record name: LEAVE IT BLANK
• Record type: A - IPv4 address
• Value: Your EC2 public IP
• TTL: 300 (5 minutes)
• ClicK Create Record. Wait a few minutes for the DNS changes to propagate.

Test the Domain :

curl http://example.com:8080/api/info

10. Remove :8080 Using NGINX Reverse Proxy:

1 Install Nginx

sudo apt update
sudo apt install nginx -y

2 Edit Nginx Configuration

sudo nano /etc/nginx/sites-available/default

Replace everything in the file with:

server {
    listen 80;
    server_name example.com;

    location / {
        proxy_pass http://localhost:8080/;
        proxy_set_header Host $host;
        proxy_set_header X-Real-IP $remote_addr;
        proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
    }
}

3 Restart Nginx

sudo systemctl restart nginx

Test Final result : curl http://example.com/api/info