java-microservice

name	java-microservice
description	Java 25 microservice development patterns for crypto-scout-client including modules, AMQP publishing, and WebSocket consumers
license	MIT
compatibility	opencode
metadata	{"language":"java","framework":"activej","version":"0.0.1","domain":"microservice"}

What I Do

Provide guidance for developing and maintaining the crypto-scout-client microservice, a Java 25 Maven application that collects crypto market data and publishes to RabbitMQ Streams.

Architecture

Client.java (Launcher)
├── CoreModule - Reactor and executor (virtual threads)
├── ServiceGraphModule - ActiveJ service lifecycle
├── JmxModule - JMX monitoring
├── ClientModule - AMQP publisher lifecycle
├── BybitSpotModule/BybitLinearModule - WebSocket consumers (conditional on bybit.stream.module.enabled)
├── CmcParserModule - HTTP parser consumer (conditional on cmc.parser.module.enabled)
└── WebModule - HTTP server, health endpoint, DNS

Core Components

Modules

ActiveJ DI modules for separation of concerns:

Module	Purpose
CoreModule	Reactor and executor (virtual threads)
WebModule	HTTP server, health routes, DNS configuration
ClientModule	AMQP publisher lifecycle
BybitSpotModule	Spot WebSocket streams + consumers (conditional)
BybitLinearModule	Linear WebSocket streams + consumers (conditional)
CmcParserModule	CMC HTTP parser + consumer (conditional)

AmqpPublisher

Thread-safe publisher that routes structured events to RabbitMQ Streams:

// Routes payloads to configured streams based on provider/source
// Bybit data -> bybit-stream (configured via amqp.bybit.stream)
// CMC data -> crypto-scout-stream (configured via amqp.crypto.scout.stream)
amqpPublisher.publish(payload);

Bybit Stream Consumers

WebSocket consumers extending AbstractBybitStreamConsumer:

// AbstractBybitStreamConsumer base class provides common lifecycle
BybitSpotBtcUsdtConsumer   // Spot BTC/USDT market data
BybitSpotEthUsdtConsumer   // Spot ETH/USDT market data
BybitLinearBtcUsdtConsumer // Linear BTC/USDT market data
BybitLinearEthUsdtConsumer // Linear ETH/USDT market data

CmcParserConsumer

HTTP-based data collection from CoinMarketCap:

// Retrieves Fear & Greed Index (API Pro Latest)
// Retrieves BTC/USD quotes (1D, 1W timeframes)
// Publishes to crypto-scout-stream

Health Endpoint

// GET /health - returns "ok" (200) when ready, 503 otherwise
// Used for liveness and readiness checks in container orchestration

ConfigValidator

Validates all configuration at startup:

@Override
protected void onStart() throws Exception {
    ConfigValidator.validate(AppConfig.getAsBoolean(CMC_PARSER_MODULE_ENABLED));
}

Configuration

All settings via system properties with environment variable mapping:

Property	Env Var	Default	Description
server.port	SERVER_PORT	8081	HTTP server port
amqp.rabbitmq.host	AMQP_RABBITMQ_HOST	localhost	RabbitMQ host
amqp.stream.port	AMQP_STREAM_PORT	5552	RabbitMQ Streams port
amqp.rabbitmq.username	AMQP_RABBITMQ_USERNAME	crypto_scout_mq	RabbitMQ user
amqp.rabbitmq.password	AMQP_RABBITMQ_PASSWORD	-	Required
amqp.bybit.stream	-	bybit-stream	Bybit data stream name
amqp.crypto.scout.stream	-	crypto-scout-stream	CMC data stream name
cmc.api.key	CMC_API_KEY	-	Required - CMC API key
bybit.api.key	BYBIT_API_KEY	-	Bybit API key
bybit.api.secret	BYBIT_API_SECRET	-	Bybit API secret
cmc.parser.module.enabled	CMC_PARSER_MODULE_ENABLED	true	Enable CMC module
bybit.stream.module.enabled	BYBIT_STREAM_MODULE_ENABLED	false	Enable Bybit modules

Module Loading Pattern

@Override
protected Module getModule() {
    final var modules = new LinkedList<Module>();
    modules.add(JmxModule.create());
    modules.add(ServiceGraphModule.create());
    modules.add(CoreModule.create());
    modules.add(ClientModule.create());

    if (AppConfig.getAsBoolean(BYBIT_STREAM_MODULE_ENABLED)) {
        modules.add(BybitSpotModule.create());
        modules.add(BybitLinearModule.create());
    }

    if (AppConfig.getAsBoolean(CMC_PARSER_MODULE_ENABLED)) {
        modules.add(CmcParserModule.create());
    }

    modules.add(WebModule.create());
    return combine(modules);
}

Key Dependencies

Dependency	Version	Purpose
jcryptolib	0.0.4	JSON utilities, Bybit/CMC clients
activej	6.0-rc2	Async I/O framework
stream-client	1.4.0	RabbitMQ Streams protocol
junit-jupiter	6.1.0-M1	Testing
mockito	5.21.0	Mocking

When to Use Me

Use this skill when:

• Implementing new modules or consumers
• Understanding the microservice architecture
• Configuring AMQP publishing and streams
• Working with Bybit WebSocket or CMC HTTP APIs
• Adding health checks or observability features
• Implementing configuration validation