ReactorListener (Jenkins Task Reactor 1.8 API)

All Known Implementing Classes:

ReactorListener.Aggregator
```
public interface ReactorListener
```
Receives callback during the Reactor.execute(Executor, ReactorListener). The callback happens by using the threads of Executor, which means these callbacks can occur concurrently. The callee is responsible for synchronization, if that's desired.

Author:

Kohsuke Kawaguchi

Nested Class Summary

Nested Classes
Modifier and Type Interface Description

static class ReactorListener.Aggregator
Bundles multiple listeners into one.

Field Summary

Fields
Modifier and Type Field Description

static ReactorListener NOOP

Method Summary

All Methods Instance Methods Default Methods
Modifier and Type	Method	Description
`default void`	`onAttained(Milestone milestone)`	Indicates that the following milestone was attained.
`default void`	`onTaskCompleted(Task t)`	Notifies that the execution of the task is about to finish.
`default void`	`onTaskFailed(Task t, Throwable err, boolean fatal)`	Notifies that the execution of the task have failed with an exception.
`default void`	`onTaskStarted(Task t)`	Notifies that the execution of the task is about to start.

- Field Detail
  - NOOP
```
static final ReactorListener NOOP
```
- Method Detail
  - onTaskStarted
```
default void onTaskStarted(Task t)
```
    Notifies that the execution of the task is about to start.
  - onTaskCompleted
```
default void onTaskCompleted(Task t)
```
    Notifies that the execution of the task is about to finish. This happens on the same thread that called onTaskStarted(Task).
  - onTaskFailed
```
default void onTaskFailed(Task t,
                          Throwable err,
                          boolean fatal)
```
    Notifies that the execution of the task have failed with an exception.
    
    Parameters:
    
    err - Either Error or Exception, indicating the cause of the failure.
    
    fatal - If true, this problem is fatal, and the reactor is going to terminate. If false, the reactor will continue executing after this failure.
  - onAttained
```
default void onAttained(Milestone milestone)
```
    Indicates that the following milestone was attained.