Backend Development with Java, JPA, Spring Boot and AWS

Install the Java SE development kit, download Java 17 from the Oracle download center, and set the JDK bin path in system environment variables for the command line.

Install IntelliJ community edition and configure it for Java development. Create a demo project, print hello world, and run a Java application to verify the setup.

install postman by downloading the mac or windows installer from postman.com and completing the setup, then create apis, collections, and environments for http requests like get, post, delete, and patch.

Install AWS CLI by downloading the installer for your OS and running it. Verify with aws --version and update the PATH if needed; note it uses Python under the hood.

Explore the monolithic architecture, a single jar deployment, and compare it with microservice architecture, weighing its development and testing against scalability limits and the need to rebuild for changes.

Explore soap, the simple object access protocol for web services, using xml messages with a soap envelope containing header and body, wsdl definitions, and typically running over http.

Explore the HTTP protocol as the foundation of RESTful web services, explaining stateless, connectionless client-server communication, request/response structure, and common methods like GET, POST, PUT, and DELETE.

Explore representational state transfer (REST) as an HTTP-based architectural style, identifying resources by URI and returning JSON or XML representations without a service definition.

Switch from monolithic to microservice architecture by splitting into independent services with separate databases, deployable on different servers, communicating via http rest APIs, enabling independent scaling and language flexibility.

Understand cloud computing fundamentals and why organizations use platforms like AWS, Azure, Google Cloud, and IBM Cloud to deploy scalable, cost-efficient web applications.

Explore Amazon Web Services fundamentals, covering core services like EC2, S3, RDS, DynamoDB, and Elastic Container Registry, and learn how security, flexibility, scalability, and elasticity enable rapid cloud deployment.

Understand virtual private cloud, a region-based, logically isolated network with public and private subnets to secure applications and databases. Learn how IP address ranges and gateways enforce access control.

Explore how AWS ECS and ECR orchestrate containerized Java apps by building Docker images with Gradle, storing them in a registry, and deploying via clusters, task definitions, and services.

Explore why Spring and Spring Boot win in Java apps, by unpacking the dependency inversion principle and how Spring's inversion of control injects abstractions via constructors and annotations.

Learn to set up a spring boot microservice with gradle, lombok, web, and jpa, configure yaml, expose a hello endpoint at /vehicles/hello, and prepare for AWS deployment on port 8080.

Configure the AWS CLI and push a docker image to a private ECR repository, using get-login-password, docker login, and tag mutability for CI/CD with Jenkins.

deploy a spring boot microservice to aws fargate via ecs, create a cluster and task definition, run a service, and access the vehicles endpoint on port 8080.

Create and dockerize a new user service from scratch with Spring Boot, Gradle, and Java 17, run locally, and prepare for AWS Cognito integration.

Explore the fundamentals of AWS Cognito as an identity platform handling authentication and authorization with user pools and identity pools, including JWT tokens, client ID, and user pool ID.

Learn to configure AWS Cognito in a Spring Boot app by wiring environment variables through application YAML, using AWS Secrets Manager, and setting up credentials providers for user pool operations.

Create and save new users by transforming Java user objects into AWS Cognito attributes using the Cognito configuration and a Spring component user builder, via JSON REST calls.

Continue building AWS Cognito admin create user request, transforming a user into a Cognito-compatible request with verified email and phone attributes, using pool ID.

Update a Cognito user with a permanent password using an admin set user password request and builder pattern, then map AWS attributes to a Java user object.

Learn to validate user input, return clear error messages, and handle exceptions with a base controller and @ExceptionHandler, using response entities to emit 400 bad request and 201 created statuses.

Learn to validate user input in Spring Boot using Jakarta validation annotations, handle not blank and size constraints, and implement a global exception handler to return concise error messages.

Explain the standard session and cookie approach to authentication in restful Java backends, using server-stored sessions and cookies with session ids, and discuss web tokens as a scalable alternative.

Learn to implement login with AWS Cognito to obtain a JWT, calculate a secret hash, and use access, ID, and refresh tokens for role-based authorization.

Leverage Cognito login and JWT tokens to authorize requests, define a profile enum for standard users and administrators, and map Cognito profile attributes to the user object.

Parse the JWT payload to extract the user id, and fetch the user via the Cognito user service. Store the user in a per-request user context to enforce authorization checks.

Implement admin-only access by using a JWT filter and user context to validate Cognito id tokens, enabling or denying endpoints such as getting all users and creating users.

builds the core car rental module by modeling a vehicle entity with status and owner. uses an api gateway to route requests between car rental and user services.

Implement a post endpoint to create vehicles with a generated UUID, status available, and null owner and association date, while defining brand, model, and license plate in JSON.

Validate vehicle creation inputs with Jakarta validation constraints, ensuring license plate number, model, and brand are mandatory, and handle errors via a Rest controller advice returning 400 bad request.

expose get all vehicles and get by id endpoints using a vehicle service and repository, with not found handling on port 8081.

Implement a delete endpoint to remove the vehicle-to-user association, validating the vehicle is currently associated, then nullifying the owner and association date, and setting status to available.

Set up a car rental VPC with two subnets across two availability zones and attach an internet gateway, then provision an AWS RDS MySQL database in the VPC.

Learn to configure database connections in AWS by using environment variables for url, username, and password, avoiding hard-coded values, and reference them in your application.

Test the cloud database by inserting vehicles via the application and retrieving all records from AWS RDS, confirming cloud DB interaction distinct from the local database.