Logging

Iotellect libraries report their activities via logging. To enable and configure logging in the Java application that uses Iotellect Server API or Agent SDK, call Log.start() method and pass the URL of logging configuration file to it. You can copy this file from Iotellect Server or Iotellect Client installation directory. Edit this file by changing logging level in certain categories for debugging purposes.

It's also possible to use logging in server or widget scripts. Logging produced by server scripts will be appended to server log file (logs/server.log). Widget script logging will be appended to Iotellect Client log file (logs/client.log) or java applet console (if using Web UI).

By default, all categories in the logging configuration files are set up to pass messages at INFO and higher levels. Thus, to write a certain string to a log file, you can use the following code: 

Logger.getLogger("ag.mycategory").info("Hello world!");

Standard Logging Categories

Standard logging categories used by Iotellect core modules and some plugins are defined in the Log class. It has a lot of pre-configured static loggers that can be used directly:

Log.DATABASE.info("Database problem detected");

Logging via Info Events

Sometimes it may be practical to use system events for logging arbitrary information. Logging data via events has several benefits:

  • System operators will be able to see logging output in event logs or even operator-level UIs
  • Logging will be bound to a specific context representing a device, system resource or user-defined resource
  • Logging output will be persistently stored in the server database

Use programmatic generation of Info events to enable event-based development logging. Each instance of Info event contains an arbitrary informational string that may include your custom output.

Was this page helpful?