org.springframework.context

Interface SmartLifecycle

All Superinterfaces:

Lifecycle, Phased

All Known Subinterfaces:

MessageListenerContainer

All Known Implementing Classes:

AbstractBrokerMessageHandler, AbstractJmsListeningContainer, AbstractMessageListenerContainer, AbstractPollingMessageListenerContainer, AnnotatedEndpointConnectionManager, ConnectionManagerSupport, DefaultMessageListenerContainer, EndpointConnectionManager, GenericMessageEndpointManager, JmsListenerEndpointRegistry, JmsMessageEndpointManager, SchedulerFactoryBean, SimpAnnotationMethodMessageHandler, SimpleBrokerMessageHandler, SimpleMessageListenerContainer, StompBrokerRelayMessageHandler, SubProtocolWebSocketHandler, UserDestinationMessageHandler, WebSocketAnnotationMethodMessageHandler, WebSocketConnectionManager, WebSocketHandlerMapping, WebSocketStompClient

public interface SmartLifecycle
extends Lifecycle, Phased

An extension of the Lifecycle interface for those objects that require to be started upon ApplicationContext refresh and/or shutdown in a particular order.

The isAutoStartup() return value indicates whether this object should be started at the time of a context refresh. The callback-accepting stop(Runnable) method is useful for objects that have an asynchronous shutdown process. Any implementation of this interface must invoke the callback's run() method upon shutdown completion to avoid unnecessary delays in the overall ApplicationContext shutdown.

This interface extends Phased, and the getPhase() method's return value indicates the phase within which this Lifecycle component should be started and stopped. The startup process begins with the lowest phase value and ends with the highest phase value (Integer.MIN_VALUE is the lowest possible, and Integer.MAX_VALUE is the highest possible). The shutdown process will apply the reverse order. Any components with the same value will be arbitrarily ordered within the same phase.

Example: if component B depends on component A having already started, then component A should have a lower phase value than component B. During the shutdown process, component B would be stopped before component A.

Any explicit "depends-on" relationship will take precedence over the phase order such that the dependent bean always starts after its dependency and always stops before its dependency.

Any Lifecycle components within the context that do not also implement SmartLifecycle will be treated as if they have a phase value of 0. This allows a SmartLifecycle component to start before those Lifecycle components if the SmartLifecycle component has a negative phase value, or the SmartLifecycle component may start after those Lifecycle components if the SmartLifecycle component has a positive phase value.

Note that, due to the auto-startup support in SmartLifecycle, a SmartLifecycle bean instance will usually get initialized on startup of the application context in any case. As a consequence, the bean definition lazy-init flag has very limited actual effect on SmartLifecycle beans.

Since:

3.0

Author:

Mark Fisher, Juergen Hoeller, Sam Brannen

See Also:

LifecycleProcessor, ConfigurableApplicationContext

Field Summary

Fields

Modifier and Type	Field and Description
static int	DEFAULT_PHASE The default phase for SmartLifecycle: Integer.MAX_VALUE.

Method Summary

Modifier and Type	Method and Description
default int	getPhase() Return the phase that this lifecycle object is supposed to run in.
default boolean	isAutoStartup() Returns true if this Lifecycle component should get started automatically by the container at the time that the containing ApplicationContext gets refreshed.
default void	stop(Runnable callback) Indicates that a Lifecycle component must stop if it is currently running.

Methods inherited from interface org.springframework.context.Lifecycle

isRunning, start, stop

Field Detail

DEFAULT_PHASE

static final int DEFAULT_PHASE

The default phase for SmartLifecycle: Integer.MAX_VALUE.

This is different from the common phase 0 associated with regular Lifecycle implementations, putting the typically auto-started SmartLifecycle beans into a later startup phase and an earlier shutdown phase.

Since:

5.1

See Also:

getPhase(), DefaultLifecycleProcessor.getPhase(Lifecycle), Constant Field Values

Method Detail

isAutoStartup

default boolean isAutoStartup()

Returns true if this Lifecycle component should get started automatically by the container at the time that the containing ApplicationContext gets refreshed.

A value of false indicates that the component is intended to be started through an explicit Lifecycle.start() call instead, analogous to a plain Lifecycle implementation.

The default implementation returns true.

See Also:

Lifecycle.start(), getPhase(), LifecycleProcessor.onRefresh(), ConfigurableApplicationContext.refresh()

stop

default void stop(Runnable callback)

Indicates that a Lifecycle component must stop if it is currently running.

The provided callback is used by the LifecycleProcessor to support an ordered, and potentially concurrent, shutdown of all components having a common shutdown order value. The callback must be executed after the SmartLifecycle component does indeed stop.

The LifecycleProcessor will call only this variant of the stop method; i.e. Lifecycle.stop() will not be called for SmartLifecycle implementations unless explicitly delegated to within the implementation of this method.

The default implementation delegates to Lifecycle.stop() and immediately triggers the given callback in the calling thread. Note that there is no synchronization between the two, so custom implementations may at least want to put the same steps within their common lifecycle monitor (if any).

See Also:

Lifecycle.stop(), getPhase()

getPhase

default int getPhase()

Return the phase that this lifecycle object is supposed to run in.

The default implementation returns DEFAULT_PHASE in order to let stop() callbacks execute after regular Lifecycle implementations.

Specified by:

getPhase in interface Phased

See Also:

isAutoStartup(), Lifecycle.start(), stop(Runnable), DefaultLifecycleProcessor.getPhase(Lifecycle)