ComputerListener (Jenkins core 2.331 API)

java.lang.Object
- hudson.slaves.ComputerListener

All Implemented Interfaces:

ExtensionPoint

Direct Known Subclasses:

ChannelPinger, Computer.DisplayExecutor.InternalComputerListener, JnlpSlaveRestarterInstaller, LogRecorder.ComputerLogInitializer, Node.InternalComputerListener, NodeMonitorUpdater, StandardOutputSwapper, SystemProperties.AgentCopier
```
public abstract class ComputerListener
extends Object
implements ExtensionPoint
```
Receives notifications about status changes of Computers.

Since:

1.246

Author:

Kohsuke Kawaguchi

Nested Class Summary
- Nested classes/interfaces inherited from interface hudson.ExtensionPoint
  ExtensionPoint.LegacyInstancesAreScopedToHudson

Constructor Summary

Constructors
Constructor and Description

ComputerListener()

Constructors
Constructor and Description
`ComputerListener()`

Method Summary

All Methods Static Methods Instance Methods Concrete Methods Deprecated Methods
Modifier and Type	Method and Description
`static ExtensionList<ComputerListener>`	`all()` All the registered `ComputerListener`s.
`void`	`onConfigurationChange()` Called when configuration of the node was changed, a node is added/removed, etc.
`void`	`onLaunchFailure(Computer c, TaskListener taskListener)` Called when an agent attempted to connect via `ComputerLauncher` but it failed.
`void`	`onOffline(Computer c)` Deprecated. since 1.571. Use `onOffline(Computer, OfflineCause)` instead.
`void`	`onOffline(Computer c, OfflineCause cause)` Called right after a `Computer` went offline.
`void`	`onOnline(Computer c)` Deprecated. as of 1.292 Use `onOnline(Computer, TaskListener)`
`void`	`onOnline(Computer c, TaskListener listener)` Called right after a `Computer` comes online.
`void`	`onTemporarilyOffline(Computer c, OfflineCause cause)` Indicates that the computer was marked as temporarily offline by the administrator.
`void`	`onTemporarilyOnline(Computer c)` Indicates that the computer was marked as temporarily online by the administrator.
`void`	`preLaunch(Computer c, TaskListener taskListener)` Called before a `ComputerLauncher` is asked to launch a connection with `Computer`.
`void`	`preOnline(Computer c, hudson.remoting.Channel channel, FilePath root, TaskListener listener)` Called before a `Computer` is marked online.
`void`	`register()` Deprecated. as of 1.286 put `Extension` on your class to have it auto-registered.
`boolean`	`unregister()` Unregisters this `ComputerListener` so that it will never receive further events.

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Constructor Detail
  - ComputerListener
```
public ComputerListener()
```
- Method Detail
  - preLaunch
```
public void preLaunch(Computer c,
                      TaskListener taskListener)
               throws IOException,
                      InterruptedException
```
    Called before a ComputerLauncher is asked to launch a connection with Computer.
    This enables you to do some configurable checks to see if we want to bring this agent online or if there are considerations that would keep us from doing so.
    Throwing AbortException would let you veto the launch operation. Other thrown exceptions will also have the same effect, but their stack trace will be dumped, so they are meant for error situation.
    
    Parameters:
    
    c - Computer that's being launched. Never null.
    
    taskListener - Connected to the agent console log. Useful for reporting progress/errors on a lengthy operation. Never null.
    
    Throws:
    
    AbortException - Exceptions will be recorded to the listener, and the computer will not become online.
    
    IOException
    
    InterruptedException
    
    Since:
    
    1.402
  - onLaunchFailure
```
public void onLaunchFailure(Computer c,
                            TaskListener taskListener)
                     throws IOException,
                            InterruptedException
```
    Called when an agent attempted to connect via ComputerLauncher but it failed.
    
    Parameters:
    
    c - Computer that was trying to launch. Never null.
    
    taskListener - Connected to the agent console log. Useful for reporting progress/errors on a lengthy operation. Never null.
    
    Throws:
    
    IOException
    
    InterruptedException
    
    Since:
    
    1.402
  - preOnline
```
public void preOnline(Computer c,
                      hudson.remoting.Channel channel,
                      FilePath root,
                      TaskListener listener)
               throws IOException,
                      InterruptedException
```
    Called before a Computer is marked online.
    This enables you to do some work on all the agents as they get connected. Unlike onOnline(Computer, TaskListener), a failure to carry out this function normally will prevent a computer from marked as online.
    
    Parameters:
    
    channel - This is the channel object to talk to the agent. (This is the same object returned by Computer.getChannel() once it's connected.
    
    root - The directory where this agent stores files. The same as Node.getRootPath(), except that method returns null until the agent is connected. So this parameter is passed explicitly instead.
    
    listener - This is connected to the launch log of the computer. Since this method is called synchronously from the thread that launches a computer, if this method performs a time-consuming operation, this listener should be notified of the progress. This is also a good listener for reporting problems.
    
    Throws:
    
    IOException - Exceptions will be recorded to the listener, and the computer will not become online.
    
    InterruptedException - Exceptions will be recorded to the listener, and the computer will not become online.
    
    Since:
    
    1.295
    
    See Also:
    
    onOnline(Computer, TaskListener)
  - onOnline
```
@Deprecated
public void onOnline(Computer c)
```
    Deprecated. as of 1.292 Use onOnline(Computer, TaskListener)
    
    Called right after a Computer comes online.
  - onOnline
```
public void onOnline(Computer c,
                     TaskListener listener)
              throws IOException,
                     InterruptedException
```
    Called right after a Computer comes online.
    This enables you to do some work on all the agents as they get connected. Any thrown Exceptions will be recorded to the listener. No Exception will put the computer offline, however any Error will put the computer offline since they indicate unrecoverable conditions.
    Starting Hudson 1.312, this method is also invoked for the master, not just for agents.
    
    Parameters:
    
    listener - This is connected to the launch log of the computer or Jenkins master. Since this method is called synchronously from the thread that launches a computer, if this method performs a time-consuming operation, this listener should be notified of the progress. This is also a good listener for reporting problems.
    
    Throws:
    
    IOException - Exceptions will be recorded to the listener. Note that throwing an exception doesn't put the computer offline.
    
    InterruptedException - Exceptions will be recorded to the listener. Note that throwing an exception doesn't put the computer offline.
    
    See Also:
    
    preOnline(Computer, Channel, FilePath, TaskListener)
  - onOffline
```
@Deprecated
public void onOffline(Computer c)
```
    Deprecated. since 1.571. Use onOffline(Computer, OfflineCause) instead.
    
    Called right after a Computer went offline.
  - onOffline
```
public void onOffline(@NonNull
                      Computer c,
                      @CheckForNull
                      OfflineCause cause)
```
    Called right after a Computer went offline.
    
    Since:
    
    1.571
  - onTemporarilyOnline
```
public void onTemporarilyOnline(Computer c)
```
    Indicates that the computer was marked as temporarily online by the administrator. This is the reverse operation of onTemporarilyOffline(Computer, OfflineCause)
    
    Since:
    
    1.452
  - onTemporarilyOffline
```
public void onTemporarilyOffline(Computer c,
                                 OfflineCause cause)
```
    Indicates that the computer was marked as temporarily offline by the administrator. This is the reverse operation of onTemporarilyOnline(Computer)
    
    Since:
    
    1.452
  - onConfigurationChange
```
public void onConfigurationChange()
```
    Called when configuration of the node was changed, a node is added/removed, etc.
    This callback is to signal when there's any change to the list of agents registered to the system, including addition, removal, changing of the setting, and so on.
    
    Since:
    
    1.377
  - register
```
@Deprecated
public final void register()
```
    Deprecated. as of 1.286 put Extension on your class to have it auto-registered.
    
    Registers this ComputerListener so that it will start receiving events.
  - unregister
```
public final boolean unregister()
```
    Unregisters this ComputerListener so that it will never receive further events.
    Unless ComputerListener is unregistered, it will never be a subject of GC.
  - all
```
public static ExtensionList<ComputerListener> all()
```
    All the registered ComputerListeners.

Class ComputerListener

Nested Class Summary

Nested classes/interfaces inherited from interface hudson.ExtensionPoint

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Constructor Detail

ComputerListener

Method Detail

preLaunch

onLaunchFailure

preOnline

onOnline

onOnline

onOffline

onOffline

onTemporarilyOnline

onTemporarilyOffline

onConfigurationChange

register

unregister

all