org.neo4j.kernel.lifecycle
Class LifeSupport

java.lang.Object
  org.neo4j.kernel.lifecycle.LifeSupport

All Implemented Interfaces:

Lifecycle

public class LifeSupport
extends Object
implements Lifecycle

Support class for handling collections of Lifecycle instances. Manages the transitions from one state to another.

To use this, first add instances to it that implement the Lifecycle interface. When lifecycle methods on this class are called it will try to invoke the same methods on the registered instances.

Components that internally owns other components that has a lifecycle can use this to control them as well.

Constructor Summary

LifeSupport()

Method Summary

<T> T	add(T instance) Add a new Lifecycle instance.
void	addLifecycleListener(LifecycleListener listener)
void	clear() Shutdown and throw away all the current instances.
void	dump(org.neo4j.kernel.impl.util.StringLogger logger)
Iterable<Lifecycle>	getLifecycleInstances()
LifecycleStatus	getStatus()
void	init() Initialize all registered instances, transitioning from status NONE to STOPPED.
boolean	remove(Object instance)
void	removeLifecycleListener(LifecycleListener listener)
void	restart(Lifecycle instance) Restart an individual instance.
void	shutdown() Shutdown all registered instances, transitioning from either STARTED or STOPPED to SHUTDOWN.
void	start() Start all registered instances, transitioning from STOPPED to STARTED.
void	stop() Stop all registered instances, transitioning from STARTED to STOPPED.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

LifeSupport

public LifeSupport()

Method Detail

init

public void init()
          throws LifecycleException

Initialize all registered instances, transitioning from status NONE to STOPPED.

If transition fails, then it goes to STOPPED and then SHUTDOWN, so it cannot be restarted again.

Specified by:

init in interface Lifecycle

Throws:

LifecycleException

start

public void start()
           throws LifecycleException

Start all registered instances, transitioning from STOPPED to STARTED.

If it was previously not initialized, it will be initialized first.

If any instance fails to start, the already started instances will be stopped, so that the overall status is STOPPED.

Specified by:

start in interface Lifecycle

Throws:

LifecycleException

stop

public void stop()
          throws LifecycleException

Stop all registered instances, transitioning from STARTED to STOPPED.

If any instance fails to stop, the rest of the instances will still be stopped, so that the overall status is STOPPED.

Specified by:

stop in interface Lifecycle

Throws:

Exception

LifecycleException

shutdown

public void shutdown()
              throws LifecycleException

Shutdown all registered instances, transitioning from either STARTED or STOPPED to SHUTDOWN.

If any instance fails to shutdown, the rest of the instances will still be shut down, so that the overall status is SHUTDOWN.

Specified by:

shutdown in interface Lifecycle

Throws:

Exception

LifecycleException

restart

public void restart(Lifecycle instance)
             throws LifecycleException,
                    IllegalArgumentException

Restart an individual instance. All instances "after" the instance will be stopped first, so that they don't try to use it during the restart. A restart is effectively a stop followed by a start.

Parameters:

instance -

Throws:

Throwable - if any start or stop fails

IllegalArgumentException - if instance is not registered

LifecycleException

add

public <T> T add(T instance)
      throws LifecycleException

Add a new Lifecycle instance. It will immediately be transitioned to the state of this LifeSupport.

Type Parameters:

T - type of the instance

Parameters:

instance - the Lifecycle instance to add

Returns:

the instance itself

Throws:

LifecycleException - if the instance could not be transitioned properly

remove

public boolean remove(Object instance)

getLifecycleInstances

public Iterable<Lifecycle> getLifecycleInstances()

clear

public void clear()

Shutdown and throw away all the current instances. After this you can add new instances. This method does not change the status of the LifeSupport (i.e. if it was started it will remain started)

getStatus

public LifecycleStatus getStatus()

addLifecycleListener

public void addLifecycleListener(LifecycleListener listener)

removeLifecycleListener

public void removeLifecycleListener(LifecycleListener listener)

dump

public void dump(org.neo4j.kernel.impl.util.StringLogger logger)