Interface Lifecycle

All Known Subinterfaces:
Container, Context, Engine, Executor, Host, Server, Service, WebResourceRoot, WebResourceSet, Wrapper
All Known Implementing Classes:
AbstractAccessLogValve, AbstractArchiveResourceSet, AbstractFileResourceSet, AbstractResourceSet, AbstractSingleArchiveResourceSet, AccessLogValve, AuthenticatorBase, BackupManager, BasicAuthenticator, ClusterManagerBase, ClusterSingleSignOn, CombinedRealm, Connector, ContainerBase, CrawlerSessionManagerValve, DataSourceRealm, DataSourceStore, DeltaManager, DigestAuthenticator, DirResourceSet, EmptyResourceSet, ErrorReportValve, ExtendedAccessLogValve, ExtractingRoot, FailedContext, FileResourceSet, FileStore, FormAuthenticator, JAASMemoryLoginModule, JAASRealm, JarResourceSet, JarWarResourceSet, JDBCAccessLogValve, JDBCRealm, JDBCStore, JNDIRealm, JsonAccessLogValve, JsonErrorReportValve, JvmRouteBinderValve, LifecycleBase, LifecycleMBeanBase, LoadBalancerDrainingValve, LockOutRealm, ManagerBase, MapperListener, MemoryRealm, NamingResourcesImpl, NonLoginAuthenticator, NullRealm, ParallelWebappClassLoader, PersistentManager, PersistentManagerBase, PersistentValve, ProxyErrorReportValve, RealmBase, RemoteAddrValve, RemoteCIDRValve, RemoteHostValve, RemoteIpValve, ReplicatedContext, ReplicationValve, RequestFilterValve, RewriteValve, SemaphoreValve, SessionIdGeneratorBase, SimpleTcpCluster, SingleSignOn, SpnegoAuthenticator, SSLAuthenticator, SSLValve, StandardContext, StandardEngine, StandardHost, StandardManager, StandardPipeline, StandardRoot, StandardServer, StandardService, StandardSessionIdGenerator, StandardThreadExecutor, StandardVirtualThreadExecutor, StandardWrapper, StoreBase, StuckThreadDetectionValve, Tomcat.ExistingStandardWrapper, UserDatabaseRealm, ValveBase, WarResourceSet, WebappClassLoader, WebappClassLoaderBase, WebappLoader

public interface Lifecycle
Common interface for component life cycle methods. Catalina components may implement this interface (as well as the appropriate interface(s) for the functionality they support) in order to provide a consistent mechanism to start and stop the component.
The valid state transitions for components that support Lifecycle are:
            start()
  -----------------------------
  |                           |
  | init()                    |
 NEW -»-- INITIALIZING        |
 | |           |              |     ------------------«-----------------------
 | |           |auto          |     |                                        |
 | |          \|/    start() \|/   \|/     auto          auto         stop() |
 | |      INITIALIZED --»-- STARTING_PREP --»- STARTING --»- STARTED --»---  |
 | |         |                                                            |  |
 | |destroy()|                                                            |  |
 | --»-----«--    ------------------------«--------------------------------  ^
 |     |          |                                                          |
 |     |         \|/          auto                 auto              start() |
 |     |     STOPPING_PREP ----»---- STOPPING ------»----- STOPPED -----»-----
 |    \|/                               ^                     |  ^
 |     |               stop()           |                     |  |
 |     |       --------------------------                     |  |
 |     |       |                                              |  |
 |     |       |    destroy()                       destroy() |  |
 |     |    FAILED ----»------ DESTROYING ---«-----------------  |
 |     |                        ^     |                          |
 |     |     destroy()          |     |auto                      |
 |     --------»-----------------    \|/                         |
 |                                 DESTROYED                     |
 |                                                               |
 |                            stop()                             |
 ----»-----------------------------»------------------------------

 Any state can transition to FAILED.

 Calling start() while a component is in states STARTING_PREP, STARTING or
 STARTED has no effect.

 Calling start() while a component is in state NEW will cause init() to be
 called immediately after the start() method is entered.

 Calling stop() while a component is in states STOPPING_PREP, STOPPING or
 STOPPED has no effect.

 Calling stop() while a component is in state NEW transitions the component
 to STOPPED. This is typically encountered when a component fails to start and
 does not start all its sub-components. When the component is stopped, it will
 try to stop all sub-components - even those it didn't start.

 Attempting any other transition will throw LifecycleException.

 
The LifecycleEvents fired during state changes are defined in the methods that trigger the changed. No LifecycleEvents are fired if the attempted transition is not valid.
Author:
Craig R. McClanahan
  • Nested Class Summary

    Nested Classes
    Modifier and Type
    Interface
    Description
    static interface 
    Marker interface used to indicate that the instance should only be used once.
  • Field Summary

    Fields
    Modifier and Type
    Field
    Description
    static final String
    The LifecycleEvent type for the "component after destroy" event.
    static final String
    The LifecycleEvent type for the "component after init" event.
    static final String
    The LifecycleEvent type for the "component after start" event.
    static final String
    The LifecycleEvent type for the "component after stop" event.
    static final String
    The LifecycleEvent type for the "component before destroy" event.
    static final String
    The LifecycleEvent type for the "component before init" event.
    static final String
    The LifecycleEvent type for the "component before start" event.
    static final String
    The LifecycleEvent type for the "component before stop" event.
    static final String
    The LifecycleEvent type for the "configure_start" event.
    static final String
    The LifecycleEvent type for the "configure_stop" event.
    static final String
    The LifecycleEvent type for the "periodic" event.
    static final String
    The LifecycleEvent type for the "component start" event.
    static final String
    The LifecycleEvent type for the "component stop" event.
  • Method Summary

    Modifier and Type
    Method
    Description
    void
    Add a LifecycleEvent listener to this component.
    void
    Prepare to discard the object.
    Get the life cycle listeners associated with this life cycle.
    Obtain the current state of the source component.
    Obtain a textual representation of the current component state.
    void
    Prepare the component for starting.
    void
    Remove a LifecycleEvent listener from this component.
    void
    Prepare for the beginning of active use of the public methods other than property getters/setters and life cycle methods of this component.
    void
    Gracefully terminate the active use of the public methods other than property getters/setters and life cycle methods of this component.
  • Field Details

    • BEFORE_INIT_EVENT

      static final String BEFORE_INIT_EVENT
      The LifecycleEvent type for the "component before init" event.
      See Also:
    • AFTER_INIT_EVENT

      static final String AFTER_INIT_EVENT
      The LifecycleEvent type for the "component after init" event.
      See Also:
    • START_EVENT

      static final String START_EVENT
      The LifecycleEvent type for the "component start" event.
      See Also:
    • BEFORE_START_EVENT

      static final String BEFORE_START_EVENT
      The LifecycleEvent type for the "component before start" event.
      See Also:
    • AFTER_START_EVENT

      static final String AFTER_START_EVENT
      The LifecycleEvent type for the "component after start" event.
      See Also:
    • STOP_EVENT

      static final String STOP_EVENT
      The LifecycleEvent type for the "component stop" event.
      See Also:
    • BEFORE_STOP_EVENT

      static final String BEFORE_STOP_EVENT
      The LifecycleEvent type for the "component before stop" event.
      See Also:
    • AFTER_STOP_EVENT

      static final String AFTER_STOP_EVENT
      The LifecycleEvent type for the "component after stop" event.
      See Also:
    • AFTER_DESTROY_EVENT

      static final String AFTER_DESTROY_EVENT
      The LifecycleEvent type for the "component after destroy" event.
      See Also:
    • BEFORE_DESTROY_EVENT

      static final String BEFORE_DESTROY_EVENT
      The LifecycleEvent type for the "component before destroy" event.
      See Also:
    • PERIODIC_EVENT

      static final String PERIODIC_EVENT
      The LifecycleEvent type for the "periodic" event.
      See Also:
    • CONFIGURE_START_EVENT

      static final String CONFIGURE_START_EVENT
      The LifecycleEvent type for the "configure_start" event. Used by those components that use a separate component to perform configuration and need to signal when configuration should be performed - usually after BEFORE_START_EVENT and before START_EVENT.
      See Also:
    • CONFIGURE_STOP_EVENT

      static final String CONFIGURE_STOP_EVENT
      The LifecycleEvent type for the "configure_stop" event. Used by those components that use a separate component to perform configuration and need to signal when de-configuration should be performed - usually after STOP_EVENT and before AFTER_STOP_EVENT.
      See Also:
  • Method Details

    • addLifecycleListener

      void addLifecycleListener(LifecycleListener listener)
      Add a LifecycleEvent listener to this component.
      Parameters:
      listener - The listener to add
    • findLifecycleListeners

      LifecycleListener[] findLifecycleListeners()
      Get the life cycle listeners associated with this life cycle.
      Returns:
      An array containing the life cycle listeners associated with this life cycle. If this component has no listeners registered, a zero-length array is returned.
    • removeLifecycleListener

      void removeLifecycleListener(LifecycleListener listener)
      Remove a LifecycleEvent listener from this component.
      Parameters:
      listener - The listener to remove
    • init

      void init() throws LifecycleException
      Prepare the component for starting. This method should perform any initialization required post object creation. The following LifecycleEvents will be fired in the following order:
      1. INIT_EVENT: On the successful completion of component initialization.
      Throws:
      LifecycleException - if this component detects a fatal error that prevents this component from being used
    • start

      void start() throws LifecycleException
      Prepare for the beginning of active use of the public methods other than property getters/setters and life cycle methods of this component. This method should be called before any of the public methods other than property getters/setters and life cycle methods of this component are utilized. The following LifecycleEvents will be fired in the following order:
      1. BEFORE_START_EVENT: At the beginning of the method. It is as this point the state transitions to LifecycleState.STARTING_PREP.
      2. START_EVENT: During the method once it is safe to call start() for any child components. It is at this point that the state transitions to LifecycleState.STARTING and that the public methods other than property getters/setters and life cycle methods may be used.
      3. AFTER_START_EVENT: At the end of the method, immediately before it returns. It is at this point that the state transitions to LifecycleState.STARTED.
      Throws:
      LifecycleException - if this component detects a fatal error that prevents this component from being used
    • stop

      void stop() throws LifecycleException
      Gracefully terminate the active use of the public methods other than property getters/setters and life cycle methods of this component. Once the STOP_EVENT is fired, the public methods other than property getters/setters and life cycle methods should not be used. The following LifecycleEvents will be fired in the following order:
      1. BEFORE_STOP_EVENT: At the beginning of the method. It is at this point that the state transitions to LifecycleState.STOPPING_PREP.
      2. STOP_EVENT: During the method once it is safe to call stop() for any child components. It is at this point that the state transitions to LifecycleState.STOPPING and that the public methods other than property getters/setters and life cycle methods may no longer be used.
      3. AFTER_STOP_EVENT: At the end of the method, immediately before it returns. It is at this point that the state transitions to LifecycleState.STOPPED.
      Note that if transitioning from LifecycleState.FAILED then the three events above will be fired but the component will transition directly from LifecycleState.FAILED to LifecycleState.STOPPING, bypassing LifecycleState.STOPPING_PREP
      Throws:
      LifecycleException - if this component detects a fatal error that needs to be reported
    • destroy

      void destroy() throws LifecycleException
      Prepare to discard the object. The following LifecycleEvents will be fired in the following order:
      1. DESTROY_EVENT: On the successful completion of component destruction.
      Throws:
      LifecycleException - if this component detects a fatal error that prevents this component from being used
    • getState

      LifecycleState getState()
      Obtain the current state of the source component.
      Returns:
      The current state of the source component.
    • getStateName

      String getStateName()
      Obtain a textual representation of the current component state. Useful for JMX. The format of this string may vary between point releases and should not be relied upon to determine component state. To determine component state, use getState().
      Returns:
      The name of the current component state.