Deploy JAR to Cloud (AWS / GCP / Azure / DigitalOcean)

Deploying a Java JAR file to the cloud means making your application live so users can access it anytime, from anywhere. Instead of running your app on a local system, you host it on cloud servers that are scalable, reliable, and always available.

What is Cloud Deployment?

Cloud deployment is the process of hosting and running your application on remote cloud servers instead of a local machine or on-premise infrastructure. These servers are managed by cloud providers and are accessible over the internet, allowing your application to be available to users from anywhere.

Makes your application accessible over the internet.
Supports scaling to handle high traffic.
Reduces the need to manage physical infrastructure.
Improves reliability and availability.

In simple words: Cloud deployment means putting your application on the internet so anyone can access it, instead of running it only on your local computer.

Types of Cloud Services

Cloud services are mainly divided into IaaS, PaaS, and SaaS, based on how much control and responsibility you have over the infrastructure and application.

1. IaaS (Infrastructure as a Service)

IaaS provides basic computing resources such as virtual servers, storage, and networking. You are responsible for managing the operating system, runtime, and application, while the cloud provider manages the physical hardware.

You control the server, OS, and application
Offers high flexibility and customization
Suitable for advanced use cases and custom setups

Examples:

Amazon EC2 (AWS)
Google Compute Engine (GCP)
Azure Virtual Machines

? Best for full control and custom infrastructure setup.

2. PaaS (Platform as a Service)

PaaS provides a ready-to-use platform where you can deploy your application without managing servers or infrastructure. The provider handles the underlying setup, including OS and runtime.

No need to manage servers or operating system
Focus only on writing and deploying code
Faster and simpler deployment process

Examples:

AWS Elastic Beanstalk
Google App Engine
Azure App Service

? Best for quick development and easy deployment.

3. SaaS (Software as a Service)

SaaS is fully developed software that is available over the internet. You do not need to install, deploy, or manage anything—just use the application through a browser.

No setup or deployment required
Accessible from any device with internet
Fully managed by the service provider

Examples:

Gmail
Google Docs
Microsoft 365

? Best for end users who only want to use software without managing it.

Difference Between IaaS, PaaS, and SaaS

Feature	IaaS	PaaS	SaaS
Full Form	Infrastructure as a Service	Platform as a Service	Software as a Service
User Control	High	Medium	Low
Managed By Provider	Hardware, Networking	Infrastructure + Runtime	Everything
Managed By User	OS, Runtime, App	Application & Data	Nothing
Main Use	Custom setup & control	App development & deployment	Using ready-made software
Setup Complexity	High	Medium	Very Low

Preparing Your JAR File (Spring Boot)

Before deploying your application to the cloud, you need to create a JAR file. In a Spring Boot project, this is typically done using Maven.

Build your application using:

./mvnw clean package

mvn clean package

After a successful build, the JAR file will be generated inside the target folder:

target/app.jar

This JAR file contains your complete application along with all required dependencies, making it ready for deployment in any environment.

Deployment Options

Virtual Machines (IaaS)

In this approach, you deploy your JAR file on a cloud-based virtual machine. You are responsible for setting up the environment, installing required software, and running the application.

AWS EC2
GCP Compute Engine
Azure Virtual Machine
DigitalOcean Droplets

? You manually configure the server, install Java, and run your application using the JAR file.

Step-by-Step: Deploy JAR on a VM

Follow these steps to deploy and run your JAR file on a virtual machine:

1. Connect to your server

ssh ubuntu@your-server-ip

2. Install Java

sudo apt update
sudo apt install openjdk-17-jdk-y

3. Upload your JAR file

scp target/app.jar ubuntu@your-server-ip:/home/ubuntu

4. Run the application

java-jar app.jar

5. Run in background (production use)

To keep your application running even after closing the terminal:

nohup java-jar app.jar > app.log2>&1 &

This command runs the application in the background and stores logs in the app.log file.

Environment Variables Configuration

Environment variables are used to store configuration values like database URLs, ports, and API keys outside your code. This helps keep your application secure, flexible, and easy to manage.

Set environment variables

export DB_URL=your_database_url
export PORT=8080

Spring Boot configuration

server.port=${PORT}

This tells Spring Boot to read the port value from the environment variable.

Port Exposure & Firewall Rules

To make your application accessible from the internet, you need to allow traffic on the port your app is running on (e.g., 8080).

Allow port using firewall

sudo ufw allow 8080

Cloud Configuration

In addition to server-level firewall settings, you must also allow inbound traffic in your cloud provider’s dashboard:

Add an inbound rule for port 8080
Set source to allow traffic (e.g., 0.0.0.0/0 for public access)

Domain & DNS Setup

To make your application accessible using a domain name instead of an IP address, you need to configure DNS.

Buy a domain from a provider (e.g., GoDaddy)
Add an A record that points your domain to your server’s public IP address

Example:

myapp.com → 123.45.67.89

? After this setup, users can access your app using myapp.com instead of the IP address.

Enable HTTPS (SSL Certificate)

Secure your application using a free SSL certificate from Let’s Encrypt.

Install Certbot

sudo apt install certbot python3-certbot-nginx -y

Generate SSL Certificate

sudo certbot --nginx

? This will automatically configure HTTPS for your domain and secure data transfer between users and your application.

Logging & Monitoring

Logging helps track application behavior and debug issues in production.

Check logs

tail -f app.log

? Displays real-time logs of your application.

You can also use:

Cloud monitoring tools
Logging dashboards

Scaling Your JAR Application

Scaling ensures your application can handle more users and traffic efficiently.

Vertical Scaling

Increase server CPU, RAM, or storage
Suitable for small to medium workloads

Horizontal Scaling

Run multiple instances of your application
Distribute traffic using a Load Balancer

? Horizontal scaling is more reliable and commonly used in production environments.

PaaS Deployment (Simpler Option)

Instead of manual setup, you can use Platform-as-a-Service (PaaS) to deploy your application quickly.

AWS Elastic Beanstalk
GCP App Engine
Azure App Service

? Simply upload your JAR file, and the platform handles infrastructure, scaling, and deployment automatically.

Best Practices

Use environment variables (avoid hardcoding sensitive data)
Enable logging and monitoring
Always use HTTPS
Keep regular backups
Use load balancing for high traffic

These practices help keep your application secure, reliable, and scalable.

Conclusion

Deploying a JAR file to the cloud is a crucial step in making your application live, scalable, and ready for production use. It allows your application to be accessed globally while ensuring high availability and better performance.

Choose IaaS (Virtual Machines) when you need full control over infrastructure and configuration
Choose PaaS when you prefer a faster, simpler, and fully managed deployment experience

With technologies like Spring Boot and modern cloud platforms, developers can easily deploy, manage, and scale applications, making it easier to build reliable and production-ready systems.