Vert.x Examples

This module provides examples for the Vert.x RxJava 3 extension, which offers 'Rxified' versions of the standard Vert.x APIs. These examples demonstrate how to use RxJava 3 types like Single, Flowable, and Completable with Vert.x components such as the Web Client, HTTP server, Event Bus, Database clients, and Schedulers.

Note: These examples specifically use the RxJava 3 API. For RxJava 2, refer to the rxjava-2-examples module.

Vert.x Circuit Breaker is an implementation of the Circuit Breaker pattern designed for Vert.x. It monitors the success and failure of asynchronous operations to prevent cascading failures in a system. When a failure threshold is reached, the circuit 'opens', and subsequent calls are immediately diverted to a fallback method or fail fast.

Supported failure types include:

• Failures explicitly reported by your code.
• Exceptions thrown by your code.
• Uncompleted futures (timeouts).

Vert.x Config is a configuration framework for Vert.x applications that supports:

• Multiple syntaxes: JSON, properties, YAML, and HOCON.
• Multiple stores: Files, directories, HTTP, Git, Redis, system properties, and environment properties.
• Customizable processing: Define the order of configuration loading and how values are overloaded.
• Runtime reconfiguration: Support for updating configuration while the application is running.

The following files are key to understanding the Sock.js Proxy implementation:

• Java Server: src/main/java/io/vertx/example/web/proxies/Server.java
• TypeScript Client App: src/main/java/io/vertx/example/web/proxies/client/main.ts
• Generated TypeScript Proxy: src/main/java/io/vertx/example/web/proxies/client/my_service-proxy.ts (This is the proxy generated by Vert.x)

Configuration files for the build process include:

• package.json (dependencies)
• webpack.config.js (Webpack configuration)
• tsconfig.json (TypeScript compiler configuration)

The monitoring dashboard example is composed of three main components:

• MainVerticle: The entry point. It starts a Kafka broker and configures the DashboardVerticle and MetricsVerticle with their respective consumer and producer configurations.
• MetricsVerticle: Uses the Kafka producer API to produce metrics in JSON format.
• DashboardVerticle: Uses the Kafka consumer API to consume metrics and forwards them to a monitoring dashboard using the Vert.x Event Bus.

Note: In production environments, the Kafka broker is typically managed externally, and the DashboardVerticle and MetricsVerticle would be executed as separate processes with their own configurations.

Vert.x Shell can be extended by implementing custom commands. Examples of command patterns include:

• Interacting with APIs: Using HttpClient to implement commands like wget <url>.
• Periodic Data Pushing: Mimicking OS commands (like top) by pushing periodic data to the Shell.
• Capturing Keyboard Events: Implementing commands that capture user keyboard input (e.g., echokeyboard).
• Streaming Data: Using NetClient to stream remote content (e.g., starwars) and handling EventType.SIGINT to terminate the command on Ctrl-C.
• Terminal Control: Using the TermServer for total control over the user terminal, which provides simple terminal capabilities instead of shell-like features.

The mqtt-examples directory contains several implementation patterns for MQTT servers and clients:

Simple Echo

Demonstrates a basic server verticle that accepts connections and echoes back received messages.

• Server: src/main/java/io/vertx/example/mqtt/simple/Server.java
• Client: src/main/java/io/vertx/example/mqtt/simple/Client.java

Full API Usage (App)

Demonstrates a more significant portion of both the Client and Server APIs.

• Server: src/main/java/io/vertx/example/mqtt/app/Server.java
• Client: src/main/java/io/vertx/example/mqtt/app/Client.java

SSL Encrypted Connections

An implementation of the Simple echo pattern but using SSL to encrypt connections.

• Server: src/main/java/io/vertx/example/mqtt/ssl/Server.java
• Client: src/main/java/io/vertx/example/mqtt/ssl/Client.java

The following examples demonstrate how to use specific Vert.x clients in conjunction with virtual threads:

• HTTP client: See HttpClientExample.java for using the Vert.x HTTP client.
• Web client: See WebClientExample.java for using the Vert.x Web client.
• SQL client: See SqlClientExample.java for using the Vert.x SQL client.