Amberj HttpServer: A Beginner-Friendly Java Web Framework

Amberj HttpServer is a lightweight Java web framework inspired by Go and Django templating, designed to make writing server-side code easier and modular, especially for beginners. It provides a simple and intuitive API for defining routes, handling requests, and rendering templates.

Features

• Simple Route Definition: Define routes using familiar HTTP methods (get, post, put, delete, patch).
• Simple Middleware Definition: Define Middleware using use method and handle everything you want.n clean
• Template Engine: Inspired by Django templating, allows embedding dynamic content within templates.
• Request Handling: Access request parameters (path, body, headers) for processing data.
• Response Rendering: Render templates with data objects for dynamic content generation.
• Automatic JSON Conversion: Converts data objects to JSON using the com.fasterxml.jackson library.

Getting Started

1. Add Dependency

Add the Amberj HttpServer library in your pom.xml:

<repositories>
    <repository>
        <id>jitpack.io</id>
        <url>https://jitpack.io</url>
    </repository>
</repositories>

<dependency>
    <groupId>com.github.akashKarmakar02</groupId>
    <artifactId>amberj-httpserver</artifactId>
    <version>v0.1.0-beta-03</version>
</dependency>

2. Create a Server

Create a simple server in your Main class:

import com.amberj.net.httpserver.Server;
import com.amberj.net.template.Data;
import java.io.IOException;

public class Main {
    public static void main(String[] args) throws IOException {
        var server = new Server(8000);
        // Define routes and run the server
        server.run();
    }
}

3. Define Routes

Define routes using the server instance:

server.get("/", (request, response) -> {
    response.render("index"); // Render the "index.html" template
});

server.post("/users", (request, response) -> {
    var body = request.body();
    String username = body.get("username");
    String email = body.get("email");

    response.render("user_profile", new Data()
            .with("username", username)
            .with("email", email));
});

4. Templates

Create template files (e.g., .html) under resources/templates in a Maven project using Django-like syntax:

<h1>Hello, {{ username }}!</h1>

Provide the data object to render the template:

User user = new User("John Doe", "[email protected]");
response.render("user_profile", new Data().with("user", user));

Example: Sending Response with Object and Path Parameters

server.get("/users/{id}", (request, response) -> {
    String userId = request.pathParams().get("id");
    User user = // fetch user data from database based on ID

    response.render("user_profile", new Data().with("user", user));
});

Example: Handling PATCH Request

server.patch("/users/{id}", (request, response) -> {
    String userId = request.pathParams().get("id");
    var body = request.body();
    String email = body.get("email");

    // Update user email in database based on ID
    User updatedUser = // update user logic

    response.render("user_profile", new Data().with("user", updatedUser));
});

Example: Using Custom Request Handlers

You can define custom request handlers by implementing the HttpHandler interface:

import com.amberj.net.http.HttpRequest;
import com.amberj.net.http.HttpResponse;
import com.amberj.net.httpserver.HttpHandler;

public class FormHandler implements HttpHandler {

    @Override
    public void get(HttpRequest request, HttpResponse response) {
        response.render("form");
    }

    @Override
    public void post(HttpRequest request, HttpResponse response) {
        var body = request.body();
        //some processing
        
        response.redirect("/");
    }
}

import com.amberj.net.httpserver.Server;

import java.io.IOException;

public class Main {
    public static void main(String[] args) throws IOException {
        var server = new Server(3000);

        server.handle("/", new FormHandler());

        server.run();
    }
}

Additional Notes

• Amberj HttpServer is currently in beta stage (version 0.1.0-BETA-02). Features and functionalities might change in future releases.
• Error handling and advanced functionalities are not covered in this basic example.

Further Development

Amberj HttpServer is under active development. Potential future features include:

• Middleware support
• Database integration for data persistence
• Session management

We encourage you to contribute to the project's development to make it even better for beginners!

Contributing

Feel free to fork this repository and submit pull requests. Contributions are welcome!

License

Amberj HttpServer is licensed under the GPL-3.0 License. See the LICENSE file for more details.