Framework cheatsheet

Spring Boot 4 Cheatsheet

Create, run, test, configure and package Spring Boot applications.

Create and run

Generate a project — Download a starter project from start.spring.io with the dependencies you choose.
Run with Maven — Build and start the app with the Maven wrapper.
Run with Gradle — Build and start the app with the Gradle wrapper.
Package an executable jar — Build a jar that contains the app and its dependencies.
Run the jar — Start the packaged application.
Build a container image — Build an OCI image with Cloud Native Buildpacks, no Dockerfile needed. Needs Docker running.

Write a REST controller — Return objects from handler methods as JSON.
Accept a JSON body — Bind and validate a request body.
Declare a service — Register a class as a bean. Spring injects constructor arguments.
Define a JPA entity — Map a class to a database table.
Create a repository — Get CRUD methods and derived queries without writing SQL.
Handle exceptions globally — Turn exceptions into HTTP responses for all controllers.

Change the port — Set the HTTP port in application.properties.
Run with a profile — Activate application-prod.properties for one run.
Set a profile with an environment variable — Environment variables override properties, which suits containers.
Bind properties to a class — Map properties with the prefix app to a typed class.
Configure a database — Point the app at PostgreSQL. Use real credentials from the environment.

Expose Actuator endpoints — Choose which Actuator endpoints are available over HTTP.
Check application health — Call the health endpoint, for example from a load balancer or Kubernetes probe.
Run the tests — Run the unit and integration tests.
Write an integration test — Start the full application context for a test.
Test a controller — Load only the web layer and call it with MockMvc.

Angular 22 cheatsheet — Angular CLI commands and standalone component, signals, template, routing, HTTP and forms snippets.
Astro cheatsheet — Build fast content sites with Astro: components, layouts, routing, content collections, islands, endpoints and deployment.
Django 6 cheatsheet — Create projects, run migrations, test and deploy Django apps, plus the ORM queries you use every day.
.NET and ASP.NET Core 10 cheatsheet — The dotnet CLI for creating, building, testing and publishing projects, plus common ASP.NET Core and EF Core code.
Express 5 cheatsheet — Build HTTP servers and APIs with Express 5 on Node.js.
FastAPI 0.115 cheatsheet — Install, run, test and deploy FastAPI apps from the command line.