Module io.helidon.common.context

Package io.helidon.common.context

Class Contexts

java.lang.Object

io.helidon.common.context.Contexts

public final class Contexts
extends Object

Support for handling Context across thread boundaries.

Method Summary

Modifier and Type	Method	Description
static Optional<Context>	context()	Get context registry associated with current thread.
static Context	globalContext()	Global context is always present and statically shared in this JVM.
static void	runInContext(Context context, Runnable runnable)	Run the runnable in the provided context.
static <T> T	runInContext(Context context, Callable<T> callable)	Run the callable in the provided context.
static <T> T	runInContextWithThrow(Context context, Callable<T> callable)	Run the callable in the provided context throwing any exception from its execution.
static ExecutorService	wrap(ExecutorService toWrap)	Wrap an executor service to correctly propagate context to its threads.
static ScheduledExecutorService	wrap(ScheduledExecutorService toWrap)	Wrap a scheduled executor service to correctly propagate context to its threads.

Methods inherited from class java.lang.Object

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

Method Detail

context

public static Optional<Context> context()

Get context registry associated with current thread.

Returns:

context that is associated with current thread or empty if none is

globalContext

public static Context globalContext()

Global context is always present and statically shared in this JVM. This is similar to Singleton scope when using an injection engine. Global context is also used as a parent for newly created contexts, unless you specify a parent using Context.Builder.parent(Context). Registering any instance in this context will make it available to any component in this JVM.

Returns:

global context instance, never null

wrap

public static ExecutorService wrap(ExecutorService toWrap)

Wrap an executor service to correctly propagate context to its threads.

Parameters:

toWrap - executor service

Returns:

a new executor service wrapping the provided one

wrap

public static ScheduledExecutorService wrap(ScheduledExecutorService toWrap)

Wrap a scheduled executor service to correctly propagate context to its threads. Note that all scheduled methods are going to run in context of the thread scheduling the tasks.

Parameters:

toWrap - executor service

Returns:

a new executor service wrapping the provided one

runInContext

public static void runInContext(Context context,
                                Runnable runnable)

Run the runnable in the provided context. The runnable can use context() to retrieve the context.

Parameters:

context - context to run in

runnable - runnable to execute in context

runInContext

public static <T> T runInContext(Context context,
                                 Callable<T> callable)

Run the callable in the provided context. The callable can use context() to retrieve the context.

Type Parameters:

T - return type of the callable

Parameters:

context - context to run in

callable - callable to execute in context

Returns:

the result of the callable

Throws:

RuntimeException - in case the Callable.call() threw a runtime exception

runInContextWithThrow

public static <T> T runInContextWithThrow(Context context,
                                          Callable<T> callable)
                                   throws Exception

Run the callable in the provided context throwing any exception from its execution. The callable can use context() to retrieve the context.

Type Parameters:

T - return type of the callable

Parameters:

context - context to run in

callable - callable to execute in context

Returns:

the result of the callable

Throws:

Exception - If thrown in Callable.call()