The SaxEventRecorder class from the logback.core package can be used to record SAX events for use in a Logback configuration file.

Here is an example of how the SaxEventRecorder class could be used to record SAX events from a XML configuration file:

import ch.qos.logback.core.joran.spi.JoranException;
import ch.qos.logback.core.joran.spi.SaxEventRecorder;
import org.xml.sax.InputSource;

//...

SaxEventRecorder recorder = new SaxEventRecorder();
try {
    recorder.recordEvents(new InputSource(new FileInputStream("logback.xml")));
} catch (FileNotFoundException | JoranException e) {
    // handle exceptions
}

List<SaxEvent> events = recorder.saxEventList;

// process events

In this example, a new SaxEventRecorder object is created and its recordEvents() method is called to record events from the XML configuration file "logback.xml".

The events are stored in the saxEventList field of the recorder object and can be processed later as per your requirement.

This class is mainly used for recording the SAX event which is useful for debugging and testing of Logback configuration. You can use it for maintaining the SAX event which can be used for further processing.

It's up to the developer to choose when and how to use this class, but it's commonly used to record the SAX events from configuration file.

Please note that in the example above, there is an assumption that the logback.xml file exist in the current folder and have necessary permission to read the file.