org.eclipse.jetty.util.component.LifeCycle Maven / Gradle / Ivy
//
// ========================================================================
// Copyright (c) 1995-2018 Mort Bay Consulting Pty. Ltd.
// ------------------------------------------------------------------------
// All rights reserved. This program and the accompanying materials
// are made available under the terms of the Eclipse Public License v1.0
// and Apache License v2.0 which accompanies this distribution.
//
// The Eclipse Public License is available at
// http://www.eclipse.org/legal/epl-v10.html
//
// The Apache License v2.0 is available at
// http://www.opensource.org/licenses/apache2.0.php
//
// You may elect to redistribute this code under either of these licenses.
// ========================================================================
//
package org.eclipse.jetty.util.component;
import java.util.EventListener;
import org.eclipse.jetty.util.annotation.ManagedObject;
import org.eclipse.jetty.util.annotation.ManagedOperation;
/* ------------------------------------------------------------ */
/**
* The lifecycle interface for generic components.
*
* Classes implementing this interface have a defined life cycle
* defined by the methods of this interface.
*
*
*/
@ManagedObject("Lifecycle Interface for startable components")
public interface LifeCycle
{
/* ------------------------------------------------------------ */
/**
* Starts the component.
* @throws Exception If the component fails to start
* @see #isStarted()
* @see #stop()
* @see #isFailed()
*/
@ManagedOperation(value="Starts the instance", impact="ACTION")
public void start()
throws Exception;
/* ------------------------------------------------------------ */
/**
* Stops the component.
* The component may wait for current activities to complete
* normally, but it can be interrupted.
* @exception Exception If the component fails to stop
* @see #isStopped()
* @see #start()
* @see #isFailed()
*/
@ManagedOperation(value="Stops the instance", impact="ACTION")
public void stop()
throws Exception;
/* ------------------------------------------------------------ */
/**
* @return true if the component is starting or has been started.
*/
public boolean isRunning();
/* ------------------------------------------------------------ */
/**
* @return true if the component has been started.
* @see #start()
* @see #isStarting()
*/
public boolean isStarted();
/* ------------------------------------------------------------ */
/**
* @return true if the component is starting.
* @see #isStarted()
*/
public boolean isStarting();
/* ------------------------------------------------------------ */
/**
* @return true if the component is stopping.
* @see #isStopped()
*/
public boolean isStopping();
/* ------------------------------------------------------------ */
/**
* @return true if the component has been stopped.
* @see #stop()
* @see #isStopping()
*/
public boolean isStopped();
/* ------------------------------------------------------------ */
/**
* @return true if the component has failed to start or has failed to stop.
*/
public boolean isFailed();
/* ------------------------------------------------------------ */
public void addLifeCycleListener(LifeCycle.Listener listener);
/* ------------------------------------------------------------ */
public void removeLifeCycleListener(LifeCycle.Listener listener);
/* ------------------------------------------------------------ */
/** Listener.
* A listener for Lifecycle events.
*/
public interface Listener extends EventListener
{
public void lifeCycleStarting(LifeCycle event);
public void lifeCycleStarted(LifeCycle event);
public void lifeCycleFailure(LifeCycle event,Throwable cause);
public void lifeCycleStopping(LifeCycle event);
public void lifeCycleStopped(LifeCycle event);
}
/**
* Utility to start an object if it is a LifeCycle and to convert
* any exception thrown to a {@link RuntimeException}
* @param object The instance to start.
* @throws RuntimeException if the call to start throws an exception.
*/
public static void start(Object object)
{
if (object instanceof LifeCycle)
{
try
{
((LifeCycle)object).start();
}
catch(Exception e)
{
throw new RuntimeException(e);
}
}
}
/**
* Utility to stop an object if it is a LifeCycle and to convert
* any exception thrown to a {@link RuntimeException}
* @param object The instance to stop.
* @throws RuntimeException if the call to stop throws an exception.
*/
public static void stop(Object object)
{
if (object instanceof LifeCycle)
{
try
{
((LifeCycle)object).stop();
}
catch(Exception e)
{
throw new RuntimeException(e);
}
}
}
}