Module it.tidalwave.util

Package it.tidalwave.util

Interface ContextManager

public interface ContextManager

A facility to register and unregister global and local DCI contexts.

Author:

Fabrizio Giudici

Nested Class Summary

Nested Classes

Modifier and Type	Interface	Description
static class	ContextManager.Binder	A binder of local contexts, created by binder(Object...) and meant to be used in a try-with-resources: it binds the contexts to the current thread when it's created and unbinds them when it's closed.
static class	ContextManager.Inner	A locator for the ContextManager which uses the ServiceLoader facility to be independent of any DI framework.
static interface	ContextManager.RunnableWithException<E extends Throwable>	A variant of Runnable that can throw a checked exception.
static interface	ContextManager.SupplierWithException<T,E extends Throwable>	A variant of Supplier that can throw a checked exception.

Method Summary

Modifier and Type	Method	Description
void	addGlobalContext(Object context)	Adds a global context.
void	addLocalContext(Object context)	Adds a local context.
default ContextManager.Binder	binder(Object... contexts)	Creates a binder that makes it possible to bind a local context by means of a try-with-resources instead of a try/finally.
<T> Optional<T>	findContextOfType(Class<T> contextType)	Finds a current context instance of the given type.
List<Object>	getContexts()	Returns the list of current contexts, ordered by their priority.
static ContextManager	getInstance()	Returns a singleton instance.
static boolean	isInstantiated()	Returns true if the singleton has already been instantiated.
void	removeGlobalContext(Object context)	Removes a global context.
void	removeLocalContext(Object context)	Removes a local context.
static void	reset()	This method is for testing only. Resets the global ContextManagerProvider; it must be called at the test completion whenever set(ContextManagerProvider) has been called, to avoid polluting the context of further tests.
default <E extends Throwable> void	runEWithContexts(ContextManager.RunnableWithException<E> runnable, Object... contexts)	Calls a runnable with some local contexts.
<T, E extends Throwable> T	runEWithContexts(ContextManager.SupplierWithException<T,E> task, Object... contexts)	Calls a task with some local contexts.
default <V, T extends Throwable> V	runWithContext(Object context, Task<V,T> task)	Deprecated. Use runWithContexts(Runnable, Object...) or runWithContexts(Supplier, Object...)
default <V> V	runWithContext(Object context, Supplier<V> task)	Deprecated. Use runWithContexts(Runnable, Object...) or runWithContexts(Supplier, Object...)
default void	runWithContexts(Runnable runnable, Object... contexts)	Calls a runnable with some local contexts.
default <T> T	runWithContexts(Supplier<T> supplier, Object... contexts)	Calls a supplier with some local contexts.
default <V, T extends Throwable> V	runWithContexts(List<Object> contexts, Task<V,T> task)	Deprecated. Use runWithContexts(Runnable, Object...) or runWithContexts(Supplier, Object...)
default <V> V	runWithContexts(List<Object> contexts, Supplier<V> task)	Deprecated. Use runWithContexts(Runnable, Object...) or runWithContexts(Supplier, Object...)
static void	set(ContextManagerProvider provider)	This method is for testing only. Sets the global ContextManagerProvider.

Method Details

getInstance

@Nonnull
static ContextManager getInstance()

Returns a singleton instance.

Returns:

the singleton instance

isInstantiated

static boolean isInstantiated()

Returns true if the singleton has already been instantiated.. This method never instantiates it.

Returns:

true if the singleton has already been instantiated

Since:

5.0-ALPHA-4

set

static void set(@Nonnull
 ContextManagerProvider provider)

This method is for testing only. Sets the global ContextManagerProvider. See note about reset().

Parameters:

provider - the provider

See Also:

• reset()

reset

static void reset()

This method is for testing only. Resets the global ContextManagerProvider; it must be called at the test completion whenever set(ContextManagerProvider) has been called, to avoid polluting the context of further tests.

See Also:

• set(ContextManagerProvider)

getContexts

@Nonnull
List<Object> getContexts()

Returns the list of current contexts, ordered by their priority.

Returns:

the list of current contexts

findContextOfType

@Nonnull
<T> Optional<T> findContextOfType(@Nonnull
 Class<T> contextType)

Finds a current context instance of the given type.

Type Parameters:

T - the static context type

Parameters:

contextType - the dynamic context type

Returns:

the requested context

addGlobalContext

void addGlobalContext(@Nonnull
 Object context)

Adds a global context.

Parameters:

context - the new context

removeGlobalContext

void removeGlobalContext(@Nonnull
 Object context)

Removes a global context.

Parameters:

context - the context

addLocalContext

void addLocalContext(@Nonnull
 Object context)

Adds a local context.

Parameters:

context - the new context

removeLocalContext

void removeLocalContext(@Nonnull
 Object context)

Removes a local context.

Parameters:

context - the context

runWithContext

@Deprecated
default <V,
T extends Throwable> V runWithContext(@Nonnull
 Object context,
 @Nonnull
 Task<V,T> task)
                                           throws T

Deprecated.

Use runWithContexts(Runnable, Object...) or runWithContexts(Supplier, Object...)

Runs a Task associated with a new local context.

Type Parameters:

V - the type of the returned value

T - the type of the exception that can be thrown

Parameters:

context - the context

task - the task

Returns:

the value produced by the task

Throws:

T - the exception(s) thrown by the task

runWithContexts

@Deprecated
default <V,
T extends Throwable> V runWithContexts(@Nonnull
 List<Object> contexts,
 @Nonnull
 Task<V,T> task)
                                            throws T

Deprecated.

Use runWithContexts(Runnable, Object...) or runWithContexts(Supplier, Object...)

Runs a Task associated with a new bunch of local contexts.

Type Parameters:

V - the type of the returned value

T - the type of the exception that can be thrown

Parameters:

contexts - the contexts

task - the task

Returns:

the value produced by the task

Throws:

T - the exception(s) thrown by the task

runWithContext

@Deprecated
default <V> V runWithContext(@Nonnull
 Object context,
 @Nonnull
 Supplier<V> task)

Deprecated.

Use runWithContexts(Runnable, Object...) or runWithContexts(Supplier, Object...)

Runs a task associated with a new local context. This variant fits functional interfaces.

Type Parameters:

V - the type of the returned value of the task

Parameters:

context - the context

task - the task

Returns:

the value produced by the task

runWithContexts

@Deprecated
default <V> V runWithContexts(@Nonnull
 List<Object> contexts,
 @Nonnull
 Supplier<V> task)

Deprecated.

Use runWithContexts(Runnable, Object...) or runWithContexts(Supplier, Object...)

Runs a task associated with a new bunch of local contexts. This variant fits functional interfaces.

Type Parameters:

V - the type of the returned value

Parameters:

contexts - the contexts

task - the task

Returns:

the value produced by the task

runWithContexts

default void runWithContexts(@Nonnull
 Runnable runnable,
 @Nonnull
 Object... contexts)

Calls a runnable with some local contexts. This method fits functional interfaces.

Parameters:

runnable - the runnable

contexts - the contexts

Since:

3.2-ALPHA-12

runWithContexts

@Nonnull
default <T> T runWithContexts(@Nonnull
 Supplier<T> supplier,
 @Nonnull
 Object... contexts)

Calls a supplier with some local contexts. This method fits functional interfaces.

Type Parameters:

T - the type of the result

Parameters:

supplier - the supplier

contexts - the contexts

Returns:

the value returned by the supplier

Since:

3.2-ALPHA-12

runEWithContexts

default <E extends Throwable> void runEWithContexts(@Nonnull
 ContextManager.RunnableWithException<E> runnable,
 @Nonnull
 Object... contexts)
                                             throws E

Calls a runnable with some local contexts. This method fits functional interfaces.

Type Parameters:

E - the type of the thrown exception

Parameters:

runnable - the runnable to call

contexts - the contexts

Throws:

E - the original exception thrown by task

Since:

3.2-ALPHA-12

runEWithContexts

@Nonnull
<T,
E extends Throwable> T runEWithContexts(@Nonnull
 ContextManager.SupplierWithException<T,E> task,
 @Nonnull
 Object... contexts)
                                     throws E

Calls a task with some local contexts. This method fits functional interfaces.

Type Parameters:

T - the type of the returned value

E - the type of the thrown exception

Parameters:

task - the task to call

contexts - the contexts

Returns:

the value returned by the supplier

Throws:

E - the original exception thrown by task

Since:

3.2-ALPHA-12

binder

@Nonnull
default ContextManager.Binder binder(@Nonnull
 Object... contexts)

Creates a binder that makes it possible to bind a local context by means of a try-with-resources instead of a try/finally.

 try (final ContextManager.Binder binder = contextManager.binder(context))
   {
     ...
   }
 

Parameters:

contexts - the contexts

Returns:

a binder that can be used in try-with-resources

Since:

3.2-ALPHA-12