Getting Started

Getting Started

Prerequisites

You need Java 25 and the Latte CLI. If you don’t already have them:

curl -fsSL https://lattejava.org/javaenv/install | bash

javaenv install 25

javaenv global 25

curl -fsSL https://lattejava.org/cli/install | bash

Scaffold a project

Create a directory for your project and run latte init with the web template:

mkdir hello-web && cd hello-web

latte init web

The CLI prompts for a group, project name (defaults to the directory name), and SPDX license. When it finishes you have a fully wired Latte project that depends on org.lattejava:web.

Run it

The web template registers a run target that compiles the project and starts the server with the JEP-512 java run mode:

latte run

When the server starts it logs a clickable URL — Web application is available at [http://localhost:8080]. Visit it and you should see the page rendered from the template (Welcome to Latte Java!).

What’s in the template

The interesting file is src/main/java/<package>/Main.java. It serves static files and renders a JTE template for the home page:

import module java.base;
import module org.lattejava.http;
import module org.lattejava.web;

public class Main {
  public static final int PORT = 8080;
  private final JTETemplates templates = new JTETemplates(Path.of("web/templates"), Path.of("build"));
  public final Web web = new Web();

  public void main() {
    web.install(SecurityHeaders.defaults())
       .baseDir(Path.of("web"))
       .files("/static")
       .get("/", templates::html)
       .start(PORT);
  }
}

It comes with web/templates/index.jte (the rendered home page) and a web/static/ directory for assets.

A few things to notice:

  • Module imports. import module org.lattejava.http and import module org.lattejava.web pull every exported package from those modules into scope, so Web, HTTPRequest, HTTPResponse, SecurityHeaders, and JTETemplates are all available without per-package imports.
  • Templates. templates::html is a Handler reference — JTETemplates maps the request path to a template (/ → index.jte) and writes the rendered HTML. See Templates.
  • Security by default. SecurityHeaders.defaults() applies strict response headers to every response.
  • Auto-shutdown. start(int) registers a JVM shutdown hook so the HTTP server closes cleanly on Ctrl-C. You can register cleanup work with web.addShutdownTask(Runnable), or wrap Web in a try-with-resources block for explicit lifetime control.

For everything else — routing, middleware, body parsing, OIDC, and static files — keep reading.