# Deploy Java on Light Cloud

> Java runs services built with Spring Boot, Quarkus or a plain Maven or Gradle project. Light Cloud detects it from a pom.xml, build.gradle or build.gradle.kts. It runs as a container that scales with traffic and down to zero when idle.

## Java at a glance

- **Detected from:** a `pom.xml`, `build.gradle` or `build.gradle.kts`
- **Runs as:** Container that scales with traffic and to zero when idle
- **Versions:** JDK 17, 21 or 25 (default 21), read from the Gradle toolchain, `sourceCompatibility`, or Maven `java.version` and `maven.compiler.release`
- **Build:** Maven 3.9 or Gradle 8 (Gradle 9 for JDK 25), with `gradlew` when the repository has one
- **Start command:** `java -jar app.jar`
- **Port:** 8080, also passed as `SERVER_PORT` and `QUARKUS_HTTP_PORT`

## How to deploy Java

1. **Bring the code.** Pick a repository, upload a folder, or ask Claude Code or GitHub Copilot to put it online.
2. **Java, detected.** The files are read and the build is filled in. Every setting can be changed by hand.
3. **Built into a container.** An image is built and started, listening on the port the app expects.
4. **Live.** A light-cloud.io URL in minutes, a preview URL for every branch, and logs and metrics beside it.

## Frameworks on Java

- [Spring Boot](https://light-cloud.com/frameworks/spring-boot): Production Java services
- [Quarkus](https://light-cloud.com/frameworks/quarkus): Cloud-native Java

## Add a database

- [PostgreSQL](https://light-cloud.com/databases/postgresql): Shared or dedicated

## Questions

### How do I deploy Java?

Connect the repository, upload the folder, or ask Claude Code or GitHub Copilot to deploy it. Light Cloud reads the files, builds Java and returns a live URL in minutes, with a preview URL for every branch.

### How much does it cost to host Java?

The Free plan runs up to 3 server apps with $1 of usage a month and no card. A container is billed by the hour only while it runs, so an idle app costs nothing and a quiet one uses about $0.10 a month. Paid plans start at $5 a month with $5 of usage included.

### Can a Java app use a database?

Yes. Create a PostgreSQL database in the same project and set its connection string as DATABASE_URL. Databases come with paid plans, from $5 a month.

### Can I use my own Dockerfile instead?

Yes. A Dockerfile at the root of the repository always wins over detection: it is built as is and runs as a container.

Docs: https://docs.light-cloud.com/platform/frameworks/java
Page: https://light-cloud.com/runtimes/java
Deploy Java: https://console.light-cloud.com/new
Start free, no card: https://console.light-cloud.com/signup