Javalin 5.0.0 released

public static void main(String[] args) {
    var app = Javalin.create(/*config*/)
        .get("/", ctx -> ctx.result("Hello World"))
        .start(7070);
}

ctx.result(stringOrStream);           // writes string or input stream to client (`text/plain` by default)
ctx.json(myJson);                     // serializes object to JSON string and writes to client (as `application/json`)
ctx.jsonStream(myJson);               // serializes JSON directly to client (nothing buffered in memory)
ctx.writeSeekableStream(myMediaFile); // stream audio and video to client (supports seeking/skipping)
ctx.future(myFutureSupplier);         // instructs Javalin to handle request asynchronously
ctx.render("/file.ext", model);       // render template or markdown file (as `text/html`)

ctx.body();                     // get the request body as a string (caches the body)
ctx.formParam("name");          // get a form parameter
ctx.queryParam("name");         // get a query parameter
ctx.uploadedFile("name");       // get an uploaded file

// JSON methods
ctx.bodyAsClass(Clazz);         // deserialize ctx.body() to class
ctx.bodyStreamAsClass(Clazz);   // consume input stream from request body and deserialize to class

// validation
var age = ctx.queryParamAsClass("age", Integer.class)  // wraps parameter in Validator
    .check(age -> age > 18, "NOT_OLD_ENOUGH") // adds check with error message
    .get(); // gets the validated value, or throws ValidationException
var bananaBox = ctx.bodyValidator(BananaBox.class)
    .check(box -> box.weight < 5, ValidationError("WEIGHT_TOO_HIGH", Map.of("MAX_WEIGHT", 5)))
    .check(box -> box.bananas.length > 20, ValidationError("NOT_ENOUGH_BANANAS", Map.of("MIN_BANANAS", 20)))
    .getOrDefault(defaultBananaBox) // uses default if body is null, runs validation rules otherwise

app.ws("/websocket/{path}", ws -> {
    ws.onConnect(ctx -> System.out.println("Connected"));
    ws.onMessage(ctx -> {
        User user = ctx.messageAsClass(User.class); // convert from json
        ctx.send(user); // convert to json and send back
    });
    ws.onBinaryMessage(ctx -> System.out.println("Message"))
    ws.onClose(ctx -> System.out.println("Closed"));
    ws.onError(ctx -> System.out.println("Errored"));
});

app.sse("/sse", client ->
    client.sendEvent("connected", "Hello, SSE");  // can also send an object, which will be serialized
    client.onClose(() -> System.out.println("Client disconnected"));
});

import static io.javalin.apibuilder.ApiBuilder.*
...
app.routes(() -> {
    before(GlobalController::globalAction)               // handler that runs for every request to the app
    path("users", () -> {                                // push subpath /users on the router
        get(UserController::getAll);                     // get controller for /users/
        post(UserController::create);                    // post controller for /users/
        before("{userId}*", UserController:userIdCheck); // handler that runs for every request to /users/{userId} as well as al subpaths
        path("{userId}", (() -> {                        // new subpath /{userId} on the router
            get(UserController::getOne);                 // get controller for /users/{userId}
            patch(UserController::update);               // patch controller for /users/{userId}
            path("subpath", (() -> { ... });             // push subpath /subpath on the router (and pop it immediately)
        });                                              // pop subpath /{userId} on the router
        ws("events", UserController::webSocketEvents);   // websocket controller for /users/events
    });                                                  // pop subpath /users on the router
}).start(port);

var app = Javalin.create(config -> {
    config.http.generateEtags = true;
    config.http.asyncTimeout = 10_000L;
    config.routing.ignoreTrailingSlashes = true;
    config.staticFiles.add("/public", Location.CLASSPATH);
});

var app = Javalin.create(config -> {
    config.jetty.server(() -> Server());                 // set the Jetty Server
    config.jetty.sessionHandler(() -> SessionHandler()); // set the Jetty SessionHandler
    config.jetty.contextHandlerConfig(handler -> {});    // configure the Jetty ServletContextHandler
    config.jetty.wsFactoryConfig((factory) -> {});       // configure the Jetty WebSocketServletFactory
});