🔧 GuicedEE MicroProfile Config

GuicedEE Config is a MicroProfile Config implementation. It follows the MicroProfile Config specification for configuration lookups, CDI-based injection, type conversion, and config source ordering. Environment variables, system properties, and standard META-INF/microprofile-config.properties files are supported, with an optional bridge for .env files used in development.

Key points

• Standards-compliant: org.eclipse.microprofile.config APIs and annotations
• CDI-friendly: inject values using @ConfigProperty and @Inject Config
• Deterministic sources and priorities: Env vars, System props, and classpath microprofile-config.properties
• Type-safe conversion via MicroProfile Converter<T> SPI

📦 Install (Maven)

<dependency>
  <groupId>com.guicedee</groupId>
  <artifactId>guiced-config</artifactId>
</dependency>

🚀 Quick Start (CDI + Annotations)

import jakarta.inject.Inject;
import org.eclipse.microprofile.config.inject.ConfigProperty;

public class MessagingService {
  @Inject
  @ConfigProperty(name = "messaging.enabled", defaultValue = "true")
  boolean enabled;

  @Inject
  @ConfigProperty(name = "messaging.bootstrap.servers")
  String bootstrapServers;

  public void start() {
    if (enabled) {
      // use bootstrapServers
    }
  }
}

Programmatic Access (MicroProfile API)

import jakarta.inject.Inject;
import org.eclipse.microprofile.config.Config;

public class HealthProbe {
  @Inject
  Config config;

  public int livenessPort() {
    return config.getOptionalValue("liveness.port", Integer.class).orElse(8081);
  }
}

Configuration Sources and Resolution

MicroProfile Config defines a composite of sources with numeric ordinals. Higher ordinal wins when keys overlap. Typical built-in order:

• Environment Variables (e.g., MESSAGING_ENABLED) — high ordinal
• System Properties (e.g., -Dmessaging.enabled=true)
• Classpath resources META-INF/microprofile-config.properties

Additional notes

• Development convenience: this module can bridge a local .env file into the config system; values appear as MicroProfile properties but must not be committed to VCS.
• Secrets: prefer environment variables or your CI secret manager; do not store secrets in microprofile-config.properties.

Type Conversion and Custom Converters

MicroProfile Config converts common types automatically (boolean, int, Duration, etc.). You can register custom converters via SPI.

// Converter implementation
import org.eclipse.microprofile.config.spi.Converter;

public class MemorySizeConverter implements Converter<java.time.Duration> {
  @Override
  public java.time.Duration convert(String value) {
    // example only — parse "10s" or "500ms"
    if (value.endsWith("ms")) return java.time.Duration.ofMillis(Long.parseLong(value.replace("ms", "")));
    if (value.endsWith("s")) return java.time.Duration.ofSeconds(Long.parseLong(value.replace("s", "")));
    throw new IllegalArgumentException("Unsupported duration format: " + value);
  }
}

// Register via ServiceLoader
// file: META-INF/services/org.eclipse.microprofile.config.spi.Converter
//   your.pkg.MemorySizeConverter

Defaults, Profiles, and Namespaces

• Defaults: use @ConfigProperty(defaultValue = "...") for safe fallbacks.
• Namespaces: group related keys with a common prefix (e.g., messaging. or db.). This keeps microprofile-config.properties readable.
• Profiles: if your runtime supports MicroProfile profiles (e.g., mp.config.profile), profile-specific files like microprofile-config-dev.properties can override defaults. Treat this as optional; consult GUIDES for the chosen approach in this repository.

MicroProfile Config Files

Place one or more microprofile-config.properties files on the classpath under META-INF/:

# META-INF/microprofile-config.properties
messaging.enabled=true
messaging.bootstrap.servers=localhost:9092
liveness.port=8081

JPMS & SPI

• JPMS-friendly; the implementation exposes MicroProfile Config services via ServiceLoader.
• If you ship custom Converter<T> or ConfigSource implementations, register them under META-INF/services and add JPMS provides ... with ... entries if your module is named.

📚 Docs & Rules

• Pact: PACT.md
• Rules: RULES.md
• Guides: GUIDES.md (see the configuration guide and secrets policy)
• Architecture: docs/architecture/README.md
• MicroProfile Config Spec: https://github.com/eclipse/microprofile-config

📝 License & Contributions

• License: Apache 2.0
• PRs welcome; keep docs updated. When adding new configuration keys, also update .env.example, the configuration guide, and any CI references.