org.mortbay.component.AbstractLifeCycle Maven / Gradle / Ivy
//========================================================================
//$Id: AbstractLifeCycle.java,v 1.3 2005/11/11 22:55:41 gregwilkins Exp $
//Copyright 2004-2005 Mort Bay Consulting Pty. Ltd.
//------------------------------------------------------------------------
//Licensed under the Apache License, Version 2.0 (the "License");
//you may not use this file except in compliance with the License.
//You may obtain a copy of the License at
//http://www.apache.org/licenses/LICENSE-2.0
//Unless required by applicable law or agreed to in writing, software
//distributed under the License is distributed on an "AS IS" BASIS,
//WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
//See the License for the specific language governing permissions and
//limitations under the License.
//========================================================================
package org.mortbay.component;
import org.mortbay.log.Log;
import org.mortbay.util.LazyList;
/**
* Basic implementation of the life cycle interface for components.
*
* @author gregw
*/
public abstract class AbstractLifeCycle implements LifeCycle
{
private Object _lock = new Object();
private final int FAILED = -1, STOPPED = 0, STARTING = 1, STARTED = 2, STOPPING = 3;
private volatile int _state = STOPPED;
protected LifeCycle.Listener[] _listeners;
protected void doStart() throws Exception
{
}
protected void doStop() throws Exception
{
}
public final void start() throws Exception
{
synchronized (_lock)
{
try
{
if (_state == STARTED || _state == STARTING)
return;
setStarting();
doStart();
Log.debug("started {}",this);
setStarted();
}
catch (Exception e)
{
setFailed(e);
throw e;
}
catch (Error e)
{
setFailed(e);
throw e;
}
}
}
public final void stop() throws Exception
{
synchronized (_lock)
{
try
{
if (_state == STOPPING || _state == STOPPED)
return;
setStopping();
doStop();
Log.debug("stopped {}",this);
setStopped();
}
catch (Exception e)
{
setFailed(e);
throw e;
}
catch (Error e)
{
setFailed(e);
throw e;
}
}
}
public boolean isRunning()
{
return _state == STARTED || _state == STARTING;
}
public boolean isStarted()
{
return _state == STARTED;
}
public boolean isStarting()
{
return _state == STARTING;
}
public boolean isStopping()
{
return _state == STOPPING;
}
public boolean isStopped()
{
return _state == STOPPED;
}
public boolean isFailed()
{
return _state == FAILED;
}
public void addLifeCycleListener(LifeCycle.Listener listener)
{
_listeners = (LifeCycle.Listener[])LazyList.addToArray(_listeners,listener,LifeCycle.Listener.class);
}
public void removeLifeCycleListener(LifeCycle.Listener listener)
{
_listeners = (LifeCycle.Listener[])LazyList.removeFromArray(_listeners,listener);
}
private void setStarted()
{
_state = STARTED;
if (_listeners != null)
{
for (int i = 0; i < _listeners.length; i++)
{
_listeners[i].lifeCycleStarted(this);
}
}
}
private void setStarting()
{
_state = STARTING;
if (_listeners != null)
{
for (int i = 0; i < _listeners.length; i++)
{
_listeners[i].lifeCycleStarting(this);
}
}
}
private void setStopping()
{
_state = STOPPING;
if (_listeners != null)
{
for (int i = 0; i < _listeners.length; i++)
{
_listeners[i].lifeCycleStopping(this);
}
}
}
private void setStopped()
{
_state = STOPPED;
if (_listeners != null)
{
for (int i = 0; i < _listeners.length; i++)
{
_listeners[i].lifeCycleStopped(this);
}
}
}
private void setFailed(Throwable th)
{
Log.warn("failed "+this+": "+th);
Log.debug(th);
_state = FAILED;
if (_listeners != null)
{
for (int i = 0; i < _listeners.length; i++)
{
_listeners[i].lifeCycleFailure(this,th);
}
}
}
}