com.att.inno.env.impl

Class NullLifeCycle

java.lang.Object

com.att.inno.env.impl.NullLifeCycle

All Implemented Interfaces:

LifeCycle

public class NullLifeCycle
extends Object
implements LifeCycle

NullLifeCycle

This is a convenience class for those Objects which should implement LifeCycle, but don't have anything to do in any of the LifeCycle methods defined. Extending NullLifeCycle reduces the required methods for the class by 5. Any one or two of them can be overloaded.

If more are overloaded, it is recommended just to implement LifeCycle.

This only works, though, if the Object doesn't need to extend something else, due to Java's Single Extension policy. In other cases, just implement LifeCycle, and leave them empty.

Constructor Summary

Constructors

Constructor and Description
NullLifeCycle()

Method Summary

Modifier and Type	Method and Description
void	refresh(Env env) The Service will call this when (service-defined) configurations change.
void	serviceDestroy(Env env) Parallel to servicePrestart, serviceDestroy tells the implementor that the service is ending, and to take this opportunity to close out any content under it's control that can or should be closed explicitly.
void	servicePrestart(Env env) The Service using LifeCycle Elements is required to call this method at the appropriate startup time.
void	threadDestroy(Env env) Parallel to threadPrestart, threadDestroy tells the implementor that the service is ending this particular thread, and to take this opportunity to close out any content specific to this thread that can be closed.
void	threadPrestart(Env env) Many cases of implementations are not thread safe, and mechanisms must be derived to accomodate them by holding per Thread.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

NullLifeCycle

public NullLifeCycle()

Method Detail

servicePrestart

public void servicePrestart(Env env)
                     throws APIException

Description copied from interface: LifeCycle

The Service using LifeCycle Elements is required to call this method at the appropriate startup time. This is better for services than a simple static call, because the exact moment of starting can be determined programatically.

An excellent use is to establish security credentials with a backend after appropriate configurations have been read and available as part of the Env Object.

Specified by:

servicePrestart in interface LifeCycle

Throws:

APIException

threadPrestart

public void threadPrestart(Env env)
                    throws APIException

Description copied from interface: LifeCycle

Many cases of implementations are not thread safe, and mechanisms must be derived to accomodate them by holding per Thread.

ThreadLocal is a valuable resource, but start up times within the thread, depending on what it is, can be substantial.

Use ThreadPrestart to do all that is possible before actually performing work, i.e. inside of a client transaction.

Specified by:

threadPrestart in interface LifeCycle

Throws:

APIException

refresh

public void refresh(Env env)
             throws APIException

Description copied from interface: LifeCycle

The Service will call this when (service-defined) configurations change.

This mechanism allows the Service to recognize events, such as file changes, and pass on the event to all LifeCycle implementors.

The code should take the opportunity to evaluate configuration and change as necessary.

IMPORTANT:

The LifeCycle implementor cannot guarantee it will not be in the middle of a transaction, so it would behoove the implementor to construct content that does not affect anything until finished, then apply to an appropriate atomic action (i.e. setting an Object to a field), or even synchronizing. If you are using Java's "ThreadLocal", consider RefreshableThreadObject, because it implements LifeCycle, and responds to the refresh command.

Specified by:

refresh in interface LifeCycle

Throws:

APIException

threadDestroy

public void threadDestroy(Env env)
                   throws APIException

Description copied from interface: LifeCycle

Parallel to threadPrestart, threadDestroy tells the implementor that the service is ending this particular thread, and to take this opportunity to close out any content specific to this thread that can be closed.

Specified by:

threadDestroy in interface LifeCycle

Throws:

APIException

serviceDestroy

public void serviceDestroy(Env env)
                    throws APIException

Description copied from interface: LifeCycle

Parallel to servicePrestart, serviceDestroy tells the implementor that the service is ending, and to take this opportunity to close out any content under it's control that can or should be closed explicitly.

Specified by:

serviceDestroy in interface LifeCycle

Throws:

APIException