javalin/javalin

Features

• Java - A lightweight web framework for building REST APIs and web applications in Java and Kotlin.
• Lightweight Web Frameworks - Acts as a minimalist web framework for Java and Kotlin, enabling rapid development of web services.
• GraphQL Mutation Implementations - Implements server-side logic for handling GraphQL mutations to create, update, or delete data.
• Declarative Server Configurations - Defines all server routes, handlers, and settings within a centralized configuration block for explicit initialization.
• Embedded Server Lifecycles - Enables programmatic launching and termination of the embedded server with support for graceful shutdown.
• Embedded Server Management - Provides comprehensive management of the embedded Jetty server, from SSL configuration to request throttling.
• Global Server Settings - Provides centralized configuration for server parameters including thread pools, timeouts, and compression strategies.
• Handler Route Mapping - Maps incoming HTTP requests to specific handler functions during the application configuration phase.
• TLS Traffic Encryption - Secures communication channels using SSL/TLS encryption with support for PEM and keystores.
• Embedded Runtime Models - Utilizes an embedded Jetty runtime model to function as a standalone application without an external servlet container.
• Embedded Web Servers - Provides a lightweight HTTP server integrated directly into the application process as an embedded component.
• GraphQL APIs - Provides a framework for exposing data models through a GraphQL API with support for queries, mutations, and subscriptions.
• Field Resolvers - Implements resolver functions that map GraphQL queries to specific data-fetching logic.
• GraphQL Subscriptions - Implements server-side GraphQL subscriptions to provide real-time data streams to clients.
• HTTP Endpoint Mapping - Maps HTTP methods and paths to handler functions to serve data using parameters and wildcards.
• Middleware Chains - Uses a middleware chain architecture to process HTTP requests through sequential before, endpoint, and after handlers.
• Real-Time Communication - Supports bidirectional real-time communication via WebSockets and unidirectional streaming via Server-Sent Events.
• Request Context - Provides a centralized context object to read and write request and response data throughout the request lifecycle.
• REST API Frameworks - Provides a framework for building structured HTTP endpoints that process parameters and return serialized data.
• RESTful API Development - Provides a comprehensive toolkit for REST API development, including path parameters, validation, and OpenAPI generation.
• Jetty Server Launchers - Provides programmatic control over the embedded Jetty server, including host, port, and thread pool settings.
• File Upload - Provides utilities to extract uploaded files from multipart requests via the request context.
• GraphQL Frameworks - Implements a full framework for exposing GraphQL schemas with query, mutation, and subscription resolvers.
• Resolver Context Injection - Injects shared dependencies and metadata into GraphQL resolver functions using a context annotation.
• Websocket Connection Managers - Manages bidirectional communication with event handlers for WebSocket connection and session lifecycles.
• WebSocket Event Systems - Provides a WebSocket event system for managing bidirectional communication through declarative connection and message handlers.
• Status Code Response Bodies - Allows returning custom response bodies for specific HTTP status codes, tailored by content type.
• Server-Sent Events - Pushes real-time updates to connected clients over HTTP using the Server-Sent Events protocol.
• WebSocket Servers - Implements persistent bidirectional communication channels for real-time data exchange.
• OpenAPI Schema Generators - Generates OpenAPI specification documents during compilation using Java annotation processors.
• Virtual Thread Executors - Offloads request handling to lightweight virtual threads to improve scalability on supported runtimes.
• Lifecycle Hook Executions - Executes custom logic at specific server milestones, such as when the server has successfully started.
• Client Certificate Management - Implements mutual TLS by requiring and validating client certificates against a configured trust store.
• Custom Session Storage Providers - Provides a server session API for configuring custom session storage, caching, and cookie attributes.
• HTTPS Enforcements - Automatically forwards insecure HTTP requests to the secure HTTPS connector.
• Request Rate Limiting - Throttles the number of requests a client can make within a time window to protect server resources.
• Role-Based Access Control - Manages user permissions and restricts endpoint access based on assigned roles.
• TLS/SSL Configurations - Provides programmatic configuration for SSL and HTTP/2 support within the embedded server.
• TLS Certificate Management - Supports loading TLS certificate and private key material from PEM files, PKCS#12, or JKS keystores.
• WebSocket Security - Provides handlers to perform authentication and validation during the WebSocket upgrade process.
• Asynchronous Request Handlers - Processes multiple client requests concurrently using asynchronous patterns to maintain high throughput.
• Lifecycle Callbacks - Offers user-defined callbacks that trigger during specific server lifecycle stages such as startup and shutdown.
• Wrapper Handlers - Provides wrapper handlers to execute custom logic around endpoints for propagating thread-local context.
• Explicit Nullable Validators - Provides validators that return nullable types by default and require explicit markers for required values.
• Context Object Passing - Implements a context object pattern to encapsulate request and response data for access throughout the handler chain.
• Hook-Based Plugin Systems - Features a hook-based plugin system that allows extending server functionality at specific configuration and startup milestones.
• Compile-Time Generators - Provides compile-time API schema generation via annotation processing to eliminate runtime reflection overhead.
• Parameter Coercion and Validation - Validates and coerces query, form, path parameters, and headers against defined types and constraints.
• Vue Server-Side Renderers - Renders Vue component files directly on the server to generate HTML pages without a separate frontend build step.
• Exception Response Mapping - Implements mechanisms to map internal server exceptions to specific HTTP response status codes and bodies.
• Error Handlers - Provides centralized error handlers to intercept application errors and return standardized HTTP responses.
• Content-Type Differentiated Error Responses - Provides custom error responses that vary the body format based on the request's accepted content type.
• Configuration-Block Lifecycle Handlers - Allows the registration of lifecycle event handlers directly within the server's configuration block.
• Multipart Upload Utilities - Receives and processes uploaded files from multipart/form-data requests as structured objects.
• Template-Driven Rendering - Provides capabilities to generate dynamic HTML by merging data models with server-side templates.
• Request Middleware - Executes post-request middleware for cleanup and logging after every request, including exceptions.
• RESTful CRUD Implementations - Implements standardized interfaces for mapping HTTP methods to create, read, update, and delete operations.
• Route Grouping - Organizes API endpoints into nested path groups to share middleware and reduce path repetition.
• Routing Configurations - Provides a programmatic configuration block to define all routes before the server starts.
• Server-Side Rendering - Supports server-side UI rendering through pluggable template engines and buildless Vue component serving.
• Vue Reactive State Injections - Injects server-side data into Vue instances on every request as a reactive state variable.
• Server-Side Rendering Engines - Supports multiple pluggable server-side rendering engines for generating dynamic HTML responses.
• Server-Side Component Serving - Serves Vue components directly from the server into a single HTML page without requiring a build tool.
• Vue Component Bindings - Associates Vue components with server GET endpoints to apply server-side access control and middleware.
• Web Framework Plugins - Enables the addition of custom functionality through reusable modules that hook into the request lifecycle.
• REST Static File Servings - Serves static files from the classpath or file system alongside dynamic REST endpoints.

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