Routing & Parameters

Levtus was inspired by Express’ fluent syntax, Go’s performance, and Spring Boot robustness. So in our routing, it will look very familiar for those of you familiar with Express’ routing.

📚 Explanation

Levtus utlized a Trie based router. Meaning the complexity is O(L). Do not be scared, basically the performance is based on how long the path is. 🐧

As Levtus is simple, you can use a single file to declare your app.

import io.github.bernardusz.levtus.Levtus;

void main(){
    Levtus app = Levtus.create();

    app.get("/hello", ctx -> {
      ctx.text("Hello from Levtus Engine!");
    });

    app.listen(8080);
}

As you can see on the example above, an instance of Levtus (app) contains the router. Levtus has provided a shortcut for you, by calling app.method("path", ctx -> {}) you can register a path.

📑 Registering a path

As explained above, you call the method of your path on the app instance. Currently Levtus supports GET, POST, PUT, and DELETE:

void main(){
    Levtus app = Levtus.create();

    app.get("/hello", ctx -> {
      ctx.text("An incoming " + ctx.req().method() + "request!" );
    });

    app.post("/", ctx -> {
      ctx.text(ctx.req().body().toString());
    });

    app.put("/", ctx -> {
      ctx.text(ctx.req().body().toString());
    });
}

Note; Query and Patch method will be coming soon in v0.3! 🐧🐧🐧

🏷️ Path Parameters (Wildcards)

Levtus supports dynamic routing using curly braces {}. These parameters are extracted and made available through the ctx.param() method.

app.get("/user/{id}", ctx -> {
    String userId = ctx.param("id");
    ctx.json("{\"id\": \"" + userId + "\"}");
});

app.get("/posts/{category}/{slug}", ctx -> {
    String category = ctx.param("category");
    String slug = ctx.param("slug");
    ctx.text("Category: " + category + ", Post: " + slug);
});

The router uses a high-performance Prefix Tree (Trie), ensuring that parameter extraction is fast and efficient regardless of the number of routes.