https://github.com/spring-projects/spring-framework: Spring Context (Spring IO)
  • Juergen Hoeller 
/*
 * Copyright 2002-2018 the original author or authors.
 *
 * 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.springframework.context;


A common interface defining methods for start/stop lifecycle control.
The typical use case for this is to control asynchronous processing.
NOTE: This interface does not imply specific auto-startup semantics. Consider implementing SmartLifecycle for that purpose.

Can be implemented by both components (typically a Spring bean defined in a Spring context) and containers (typically a Spring ApplicationContext itself). Containers will propagate start/stop signals to all components that apply within each container, e.g. for a stop/restart scenario at runtime. 
Can be used for direct invocations or for management operations via JMX. In the latter case, the MBeanExporter will typically be defined with an InterfaceBasedMBeanInfoAssembler, restricting the visibility of activity-controlled components to the Lifecycle interface. 
Note that the present Lifecycle interface is only supported on top-level singleton beans. On any other component, the Lifecycle interface will remain undetected and hence ignored. Also, note that the extended SmartLifecycle interface provides sophisticated integration with the application context's startup and shutdown phases. 
Author:Juergen Hoeller
See Also:
Since:2.0
/**
 * A common interface defining methods for start/stop lifecycle control.
 * The typical use case for this is to control asynchronous processing.
 * <b>NOTE: This interface does not imply specific auto-startup semantics.
 * Consider implementing {@link SmartLifecycle} for that purpose.</b>
 *
 * <p>Can be implemented by both components (typically a Spring bean defined in a
 * Spring context) and containers  (typically a Spring {@link ApplicationContext}
 * itself). Containers will propagate start/stop signals to all components that
 * apply within each container, e.g. for a stop/restart scenario at runtime.
 *
 * <p>Can be used for direct invocations or for management operations via JMX.
 * In the latter case, the {@link org.springframework.jmx.export.MBeanExporter}
 * will typically be defined with an
 * {@link org.springframework.jmx.export.assembler.InterfaceBasedMBeanInfoAssembler},
 * restricting the visibility of activity-controlled components to the Lifecycle
 * interface.
 *
 * <p>Note that the present {@code Lifecycle} interface is only supported on
 * <b>top-level singleton beans</b>. On any other component, the {@code Lifecycle}
 * interface will remain undetected and hence ignored. Also, note that the extended
 * {@link SmartLifecycle} interface provides sophisticated integration with the
 * application context's startup and shutdown phases.
 *
 * @author Juergen Hoeller
 * @since 2.0
 * @see SmartLifecycle
 * @see ConfigurableApplicationContext
 * @see org.springframework.jms.listener.AbstractMessageListenerContainer
 * @see org.springframework.scheduling.quartz.SchedulerFactoryBean
 */
public interface Lifecycle {

	
Start this component.

Should not throw an exception if the component is already running.

In the case of a container, this will propagate the start signal to all
components that apply.

See Also:
  • isAutoStartup.isAutoStartup()
/**
	 * Start this component.
	 * <p>Should not throw an exception if the component is already running.
	 * <p>In the case of a container, this will propagate the start signal to all
	 * components that apply.
	 * @see SmartLifecycle#isAutoStartup()
	 */
	void start();

	
Stop this component, typically in a synchronous fashion, such that the component is fully stopped upon return of this method. Consider implementing SmartLifecycle and its stop(Runnable) variant when asynchronous stop behavior is necessary. 
Note that this stop notification is not guaranteed to come before destruction: On regular shutdown, Lifecycle beans will first receive a stop notification before the general destruction callbacks are being propagated; however, on hot refresh during a context's lifetime or on aborted refresh attempts, a given bean's destroy method will be called without any consideration of stop signals upfront. 
Should not throw an exception if the component is not running (not started yet).

In the case of a container, this will propagate the stop signal to all components
that apply.

See Also:
/**
	 * Stop this component, typically in a synchronous fashion, such that the component is
	 * fully stopped upon return of this method. Consider implementing {@link SmartLifecycle}
	 * and its {@code stop(Runnable)} variant when asynchronous stop behavior is necessary.
	 * <p>Note that this stop notification is not guaranteed to come before destruction:
	 * On regular shutdown, {@code Lifecycle} beans will first receive a stop notification
	 * before the general destruction callbacks are being propagated; however, on hot
	 * refresh during a context's lifetime or on aborted refresh attempts, a given bean's
	 * destroy method will be called without any consideration of stop signals upfront.
	 * <p>Should not throw an exception if the component is not running (not started yet).
	 * <p>In the case of a container, this will propagate the stop signal to all components
	 * that apply.
	 * @see SmartLifecycle#stop(Runnable)
	 * @see org.springframework.beans.factory.DisposableBean#destroy()
	 */
	void stop();

	
Check whether this component is currently running.

In the case of a container, this will return true only if all
components that apply are currently running.

Returns:whether the component is currently running
/**
	 * Check whether this component is currently running.
	 * <p>In the case of a container, this will return {@code true} only if <i>all</i>
	 * components that apply are currently running.
	 * @return whether the component is currently running
	 */
	boolean isRunning();

}