Blammo

Blammo provides enhanced functionality for java.util.logging, with a focus on structured logging through JSON formatting.

Core Features

JSON Formatter

The JsonFormatter class formats log records as JSON objects, making them easier to parse and analyze with log management tools. Each log entry includes:

• Timestamp
• Log level
• Logger name
• Message
• Thread information
• Stack traces (for errors)

Example JSON output:

{
  "timestamp": "2025-01-25T04:36:00Z",
  "level": "INFO",
  "logger": "com.example.MyApp",
  "message": "Application started",
  "thread": "main"
}

JsonConsoleLogger Trait

The JsonConsoleLogger trait provides a convenient way to add JSON logging to your classes:

class MyService extends JsonConsoleLogger {
  // Logger is automatically available
  logger.info("Service initialized")

  def doSomething(): Unit = {
    logger.fine("Performing operation")
    // ... your code ...
    logger.info("Operation completed")
  }
}

Usage

Setting up the JSON Formatter

import java.util.logging.{Logger, ConsoleHandler}
import dev.wishingtree.branch.blammo.JsonFormatter

val logger = Logger.getLogger("MyApp")
val handler = new ConsoleHandler()
handler.setFormatter(new JsonFormatter())
logger.addHandler(handler)

Using the JsonConsoleLogger Trait

import dev.wishingtree.branch.blammo.JsonConsoleLogger

class MyApp extends JsonConsoleLogger {
  def start(): Unit = {
    logger.info("Starting application")
    try {
      // Your application code
    } catch {
      case e: Exception =>
        // Stack trace will be included in JSON output
        logger.severe(s"Application failed: ${e.getMessage}")
    }
  }
}

Integration with Other Libraries

Blammo works seamlessly with other Branch libraries:

• Lzy can use Blammo for its logging functionality
• Piggy can use Blammo for SQL query logging
• Ursula can use Blammo for CLI application logging

Custom Formatter

You can customize the JSON output format by extending the Formatter class and overriding the format method similar to how the JsonFormatter works:

import dev.wishingtree.branch.friday.Json
import dev.wishingtree.branch.friday.Json.*
import java.util.logging.{Formatter, LogRecord}

class CustomJsonFormatter extends Formatter {
  override def format(record: LogRecord): String = {
    Json.obj(
      "name" -> jsonOrNull(record.getLoggerName),
      "level" -> JsonString(record.getLevel.toString),
      "time" -> JsonString(record.getInstant.toString),
      "message" -> jsonOrNull(record.getMessage),
      "jsonMessage" -> Json.parse(record.getMessage).getOrElse(JsonNull),
      "error" -> Json.throwable(record.getThrown),
      // Add custom fields
      "environment" -> JsonString(sys.env.getOrElse("ENV", "development")),
      "application" -> JsonString("MyApp")
    ).toJsonString + System.lineSeparator()
  }
}

This will produce log entries with additional fields:

{
  "name": "com.example.MyApp",
  "level": "INFO",
  "time": "2025-01-25T04:36:00Z",
  "message": "Application started",
  "jsonMessage": null,
  "error": null,
  "environment": "production",
  "application": "MyApp"
}