Class SyncTaskExecutor

java.lang.Object

org.springframework.util.ConcurrencyThrottleSupport

org.springframework.core.task.SyncTaskExecutor

All Implemented Interfaces:

Serializable, Executor, TaskExecutor

public class SyncTaskExecutor
extends ConcurrencyThrottleSupport
implements TaskExecutor, Serializable

TaskExecutor implementation that executes each task synchronously in the calling thread. This can be used for testing purposes but also for bounded execution in a Virtual Threads setup, relying on concurrency throttling as inherited from the base class: see ConcurrencyThrottleSupport.setConcurrencyLimit(int) (as of 7.0).

Execution in the calling thread does have the advantage of participating in its thread context, for example the thread context class loader or the thread's current transaction association. That said, in many cases, asynchronous execution will be preferable: choose an asynchronous TaskExecutor instead for such scenarios.

Since:

2.0

Author:

Juergen Hoeller

See Also:

• SimpleAsyncTaskExecutor
• Serialized Form

Field Summary

Fields inherited from class ConcurrencyThrottleSupport

logger, NO_CONCURRENCY, UNBOUNDED_CONCURRENCY

Constructor Summary

Constructors

Constructor	Description
SyncTaskExecutor()

Method Summary

Modifier and Type	Method	Description
void	execute(Runnable task)	Execute the given task synchronously, through direct invocation of its run() method.
<V extends @Nullable Object, E extends Exception> V	execute(TaskCallback<V,E> task)	Execute the given task synchronously, through direct invocation of its call() method.
protected void	onAccessRejected(String msg)	Triggered when access has been rejected due to the concurrency policy or due to interruption.
protected void	onLimitReached()	Triggered by ConcurrencyThrottleSupport.beforeAccess() when the concurrency limit has been reached.
void	setRejectTasksWhenLimitReached(boolean rejectTasksWhenLimitReached)	Specify whether to reject tasks when the concurrency limit has been reached, throwing TaskRejectedException (which extends the common RejectedExecutionException) on any further execution attempts.

Methods inherited from class ConcurrencyThrottleSupport

afterAccess, beforeAccess, getConcurrencyLimit, isThrottleActive, setConcurrencyLimit

Methods inherited from class Object

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

Constructor Details

SyncTaskExecutor

public SyncTaskExecutor()

Method Details

setRejectTasksWhenLimitReached

public void setRejectTasksWhenLimitReached(boolean rejectTasksWhenLimitReached)

Specify whether to reject tasks when the concurrency limit has been reached, throwing TaskRejectedException (which extends the common RejectedExecutionException) on any further execution attempts.

The default is false, blocking the caller until the submission can be accepted. Switch this to true for immediate rejection instead.

Since:

7.0.3

See Also:

• ConcurrencyThrottleSupport.setConcurrencyLimit(int)

execute

public void execute(Runnable task)

Execute the given task synchronously, through direct invocation of its run() method.

This can be used with a concurrency limit, analogous to a concurrency-bounded SimpleAsyncTaskExecutor setup. Also, the provided task may apply a retry policy via RetryTask.

Specified by:

execute in interface Executor

Specified by:

execute in interface TaskExecutor

Parameters:

task - the Runnable to execute (never null)

Throws:

RuntimeException - if propagated from the given Runnable

See Also:

• ConcurrencyThrottleSupport.setConcurrencyLimit(int)
• setRejectTasksWhenLimitReached(boolean)
• RetryTask.wrap(Runnable)

execute

public <V extends @Nullable Object, E extends Exception>
V execute(TaskCallback<V,E> task)
   throws E

Execute the given task synchronously, through direct invocation of its call() method.

This can be used with a concurrency limit, analogous to a concurrency-bounded SimpleAsyncTaskExecutor setup. Also, the provided task may apply a retry policy via RetryTask.

Type Parameters:

V - the returned value type, if any

E - the exception propagated, if any

Throws:

E - if propagated from the given TaskCallback

Since:

7.0

See Also:

• ConcurrencyThrottleSupport.setConcurrencyLimit(int)
• setRejectTasksWhenLimitReached(boolean)
• RetryTask(TaskCallback)

onLimitReached

protected void onLimitReached()

Description copied from class: ConcurrencyThrottleSupport

Triggered by ConcurrencyThrottleSupport.beforeAccess() when the concurrency limit has been reached. The default implementation blocks until the concurrency count allows for entering.

Overrides:

onLimitReached in class ConcurrencyThrottleSupport

onAccessRejected

protected void onAccessRejected(String msg)

Description copied from class: ConcurrencyThrottleSupport

Triggered when access has been rejected due to the concurrency policy or due to interruption.

Implementations will typically throw a corresponding exception. When returning normally, regular access will still be attempted.

The default implementation throws an IllegalStateException.

Overrides:

onAccessRejected in class ConcurrencyThrottleSupport

Parameters:

msg - the rejection message (common exception messages are designed so that they can be appended with an identifier separated by a space in custom subclasses)