Package jakarta.enterprise.concurrent

Annotation Type ManagedScheduledExecutorDefinition

@Repeatable(List.class)
@Retention(RUNTIME)
@Target(TYPE)
public @interface ManagedScheduledExecutorDefinition

Defines a ManagedScheduledExecutorService to be registered in JNDI by the container under the JNDI name that is specified in the name() attribute.

Application components can refer to this JNDI name in the lookup attribute of a Resource annotation,

 @ManagedScheduledExecutorDefinition(
     name = "java:comp/concurrent/MyScheduledExecutor",
     context = "java:comp/concurrent/MyScheduledExecutorContext",
     hungTaskThreshold = 30000,
     maxAsync = 3)
 @ContextServiceDefinition(
     name = "java:comp/concurrent/MyScheduledExecutorContext",
     propagated = APPLICATION)
  public class MyServlet extends HttpServlet {
    @Resource(lookup = "java:comp/concurrent/MyScheduledExecutor",
               name = "java:comp/concurrent/env/MyScheduledExecutorRef")
     ManagedScheduledExecutorService myScheduledExecutor;
 

Resource environment references in a deployment descriptor can similarly specify the lookup-name,

 <resource-env-ref>
    <resource-env-ref-name>java:comp/env/concurrent/MyScheduledExecutorRef</resource-env-ref-name>
    <resource-env-ref-type>jakarta.enterprise.concurrent.ManagedScheduledExecutorService</resource-env-ref-type>
    <lookup-name>java:comp/concurrent/MyScheduledExecutor</lookup-name>
 </resource-env-ref>
 

You can also define a ManagedScheduledExecutorService with the <managed-scheduled-executor> deployment descriptor element. For example,

 <managed-scheduled-executor>
    <name>java:module/concurrent/MyExecutor</name>
    <context-service-ref>java:module/concurrent/MyExecutorContext</context-service-ref>
    <hung-task-threshold>120000</hung-task-threshold>
    <max-async>5</max-async>
 </managed-scheduled-executor>
 

If a managed-scheduled-executor and ManagedScheduledExecutorDefinition have the same name, their attributes are merged to define a single ManagedScheduledExecutorService definition, with each attribute that is specified in the managed-scheduled-executor deployment descriptor entry taking precedence over the corresponding attribute of the annotation.

Since:

3.0

Required Element Summary

Required Elements

Modifier and Type	Required Element	Description
String	name	JNDI name of the ManagedScheduledExecutorService instance.

Optional Element Summary

Optional Elements

Modifier and Type	Optional Element	Description
String	context	The name of a ContextService instance which determines how context is applied to tasks and actions that run on this executor.
long	hungTaskThreshold	The amount of time in milliseconds that a task or action can execute before it is considered hung.
int	maxAsync	Upper bound on contextual tasks and actions that this executor will simultaneously execute asynchronously.

Element Detail

name

String name

JNDI name of the ManagedScheduledExecutorService instance. The JNDI name must be in a valid Jakarta EE namespace, such as,

• java:comp
• java:module
• java:app
• java:global

Returns:

ManagedScheduledExecutorService JNDI name.

context

String context

The name of a ContextService instance which determines how context is applied to tasks and actions that run on this executor.

The name can be the name of a ContextServiceDefinition or the name of a context-service deployment descriptor element or the JNDI name of the Jakarta EE default ContextService instance, java:comp/DefaultContextService.

The name of the ContextService must be no more granular than the name of this ManagedScheduledExecutorDefinition. For example, if this ManagedScheduledExecutorDefinition has a name in java:app, the ContextService can be in java:app or java:global, but not in java:module which would be ambiguous as to which module's ContextService definition should be used.

The default value, java:comp/DefaultContextService, is the JNDI name of the Jakarta EE default ContextService.

Returns:

name of the ContextService for capturing and propagating or clearing context.

Default:

"java:comp/DefaultContextService"

hungTaskThreshold

long hungTaskThreshold

The amount of time in milliseconds that a task or action can execute before it is considered hung.

The default value of -1 indicates unlimited.

Returns:

number of milliseconds after which a task or action is considered hung.

Default:

-1L

maxAsync

int maxAsync

Upper bound on contextual tasks and actions that this executor will simultaneously execute asynchronously. This constraint does not apply to tasks and actions that the executor runs inline, such as when a thread requests CompletableFuture.join() and the action runs inline if it has not yet started. This constraint also does not apply to tasks that are scheduled via the schedule* methods.

The default value of -1 indicates unbounded, although still subject to resource constraints of the system.

Returns:

upper limit on asynchronous execution.

Default:

-1