Module org.eclipse.jetty.util

Package org.eclipse.jetty.util.thread

Class Sweeper

java.lang.Object

org.eclipse.jetty.util.component.AbstractLifeCycle

org.eclipse.jetty.util.thread.Sweeper

All Implemented Interfaces:

java.lang.Runnable, LifeCycle

public class Sweeper
extends AbstractLifeCycle
implements java.lang.Runnable

A utility class to perform periodic sweeping of resources.

Sweeper.Sweepable resources may be added to or removed from a Sweeper and the resource implementation decides whether it should be swept or not.

If a Sweeper.Sweepable resources is itself a container of other sweepable resources, it will forward the sweep operation to children resources, and so on recursively.

Typical usage is to add Sweeper as a bean to an existing container:

 Server server = new Server();
 server.addBean(new Sweeper(), true);
 server.start();
 

Code that knows it has sweepable resources can then lookup the Sweeper and offer the sweepable resources to it:

 class MyComponent implements Sweeper.Sweepable
 {
     private final long creation;
     private volatile destroyed;

     MyComponent(Server server)
     {
         this.creation = System.nanoTime();
         Sweeper sweeper = server.getBean(Sweeper.class);
         sweeper.offer(this);
     }

     void destroy()
     {
         destroyed = true;
     }

     @Override
     public boolean sweep()
     {
         return destroyed;
     }
 }
 

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static interface	Sweeper.Sweepable	A Sweeper.Sweepable resource implements this interface to signal to a Sweeper or to a parent container if it needs to be swept or not.

Nested classes/interfaces inherited from class org.eclipse.jetty.util.component.AbstractLifeCycle

AbstractLifeCycle.AbstractLifeCycleListener, AbstractLifeCycle.StopException

Nested classes/interfaces inherited from interface org.eclipse.jetty.util.component.LifeCycle

LifeCycle.Listener

Field Summary

Fields inherited from class org.eclipse.jetty.util.component.AbstractLifeCycle

FAILED, STARTED, STARTING, STOPPED, STOPPING

Constructor Summary

Constructors

Constructor	Description
Sweeper(Scheduler scheduler, long period)

Method Summary

Modifier and Type	Method	Description
protected void	doStart()	Method to override to start the lifecycle
protected void	doStop()	Method to override to stop the lifecycle
int	getSize()
boolean	offer(Sweeper.Sweepable sweepable)
boolean	remove(Sweeper.Sweepable sweepable)
void	run()

Methods inherited from class org.eclipse.jetty.util.component.AbstractLifeCycle

addEventListener, getEventListeners, getState, getState, isFailed, isRunning, isStarted, isStarting, isStopped, isStopping, removeEventListener, setEventListeners, start, stop, toString

Methods inherited from class java.lang.Object

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

Constructor Detail

Sweeper

public Sweeper(Scheduler scheduler,
               long period)

Method Detail

doStart

protected void doStart()
                throws java.lang.Exception

Description copied from class: AbstractLifeCycle

Method to override to start the lifecycle

Overrides:

doStart in class AbstractLifeCycle

Throws:

AbstractLifeCycle.StopException - If thrown, the lifecycle will immediately be stopped.

java.lang.Exception - If there was a problem starting. Will cause a transition to FAILED state

doStop

protected void doStop()
               throws java.lang.Exception

Description copied from class: AbstractLifeCycle

Method to override to stop the lifecycle

Overrides:

doStop in class AbstractLifeCycle

Throws:

java.lang.Exception - If there was a problem stopping. Will cause a transition to FAILED state

getSize

public int getSize()

offer

public boolean offer(Sweeper.Sweepable sweepable)

remove

public boolean remove(Sweeper.Sweepable sweepable)

run

public void run()

Specified by:

run in interface java.lang.Runnable