Handle plugin errorsΒΆ

When a plugin throws an exception, the related end user messaging can be handled automatically, for example setting the plugin description accordingly and stopping the plugin itself.

Here is an example of correct exception handling in onRun()

  public void onStart() throws PluginStartupException {
     try {
          // This code may generate a SerialPortException if there are connection problems
          serial = new SerialHelper(PORTNAME, BAUDRATE, DATABITS, STOPBITS, PARITY, new SerialPortListener() {
             public void onDataAvailable(String data) {
     "MySensors received: " + data);

      } catch (SerialPortException ex) {
          throw new PluginStartupException("Error while connecting to serial device", ex);
  • onStart() throws PluginStartupException
  • onRun() throws PluginRuntimeException
  • onStop() throws PluginShutdownException

After catching the exception Freedomotic will:

  1. print the error message on the GUI
  2. change the plugin description using the exception message
  3. log the exception
  4. stop the plugin if it is a PluginRuntimeException