Listener

Listener receives execution callbacks.

Callbacks

runStarted(Runner runner, Action action)
runCompleted(Runner runner, Action action)
beforeAction(Context context, Action action)
actionThrowable(Context context, Action action, Throwable throwable)
afterAction(Context context, Action action, Result result)

Built-in listener factories

Listener.defaultListener()
Listener.treeListener()

Current behavior:

• defaultListener() combines status output with table summary output
• treeListener() combines status output with tree summary output

These are implemented with classes in org.paramixel.core.listener, including CompositeListener, StatusListener, SummaryListener, TableSummaryRenderer, and TreeSummaryRenderer.

Safe listener wrapper

org.paramixel.core.listener.SafeListener wraps another listener and catches listener-thrown exceptions so they do not break execution. Error subclasses (such as OutOfMemoryError and StackOverflowError) are rethrown immediately rather than caught and logged.

Custom listener example

Listener listener = new Listener() {
    @Override
    public void beforeAction(Context context, Action action) {
        System.out.println("starting " + action.getName());
    }
};

Runner runner = Runner.builder().listener(listener).build();