Package org.jgrapes.core

Class Components

java.lang.Object

org.jgrapes.core.Components

public class Components
extends Object

This class provides some utility functions.

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static interface	Components.IdInfoProvider	Implemented by classes that want a special class (scope) to be used for looking up their id or want to map to another object for getting the id (see objectId(Object)).
static class	Components.PoolingIndex<K,V>	An index of pooled items.
static interface	Components.TimeoutHandler	Instances are added to the scheduler in order to be invoked at a given time.
static class	Components.Timer	Represents a timer as created by schedule(TimeoutHandler, Instant).

Method Summary

Modifier and Type	Method	Description
static void	awaitExhaustion()	Wait until all generators and event queues are exhausted.
static boolean	awaitExhaustion(long timeout)	Wait until all generators and event queues are exhausted or the maximum wait time has expired.
static void	checkAssertions()	Utility method that checks if an assertion error has occurred while executing handlers.
static String	className(Class<?> clazz)	Returns the full name or simple name of the class depending on the log level.
static ExecutorService	defaultExecutorService()	Return the default executor service for the framework.
static String	fullObjectName(Object object)	Returns the full name of the object’s class together with an id (see objectId(Object)).
static Manager	manager(ComponentType component)	Returns a component’s manager.
static Manager	manager(ComponentType component, Channel componentChannel)	Returns a component’s manager like manager(ComponentType).
static <K, V> Map<K,V>	mapOf()	Deprecated.
static <K, V> Map<K,V>	mapOf(K k1, V v1)	Deprecated.
static <K, V> Map<K,V>	mapOf(K k1, V v1, K k2, V v2)	Deprecated.
static <K, V> Map<K,V>	mapOf(K k1, V v1, K k2, V v2, K k3, V v3)	Deprecated.
static <K, V> Map<K,V>	mapOf(K k1, V v1, K k2, V v2, K k3, V v3, K k4, V v4)	Deprecated.
static <K, V> Map<K,V>	mapOf(K k1, V v1, K k2, V v2, K k3, V v3, K k4, V v4, K k5, V v5)	Deprecated.
static <K, V> Map<K,V>	mapOf(K k1, V v1, K k2, V v2, K k3, V v3, K k4, V v4, K k5, V v5, K k6, V v6)	Deprecated.
static <K, V> Map<K,V>	mapOf(K k1, V v1, K k2, V v2, K k3, V v3, K k4, V v4, K k5, V v5, K k6, V v6, K k7, V v7)	Deprecated.
static <K, V> Map<K,V>	mapOf(K k1, V v1, K k2, V v2, K k3, V v3, K k4, V v4, K k5, V v5, K k6, V v6, K k7, V v7, K k8, V v8)	Deprecated.
static <K, V> Map<K,V>	mapOf(K k1, V v1, K k2, V v2, K k3, V v3, K k4, V v4, K k5, V v5, K k6, V v6, K k7, V v7, K k8, V v8, K k9, V v9)	Deprecated.
static <K, V> Map<K,V>	mapOf(K k1, V v1, K k2, V v2, K k3, V v3, K k4, V v4, K k5, V v5, K k6, V v6, K k7, V v7, K k8, V v8, K k9, V v9, K k10, V v10)	Deprecated.
static String	objectId(Object object)	Returns an id of the object that is unique within a specific scope.
static String	objectName(Object object)	Returns the name of the object’s class together with an id (see objectId(Object)).
static <K, V> Map<K,V>	put(Map<K,V> map, K key, V value)	Puts the given key and value in the given Map and returns the map.
static Components.Timer	schedule(Components.TimeoutHandler timeoutHandler, Duration scheduledFor)	Schedules the given timeout handler for the given offset from now.
static Components.Timer	schedule(Components.TimeoutHandler timeoutHandler, Instant scheduledFor)	Schedules the given timeout handler for the given instance.
static void	setDefaultExecutorService(ExecutorService defaultExecutorService)	Set the default executor service for the framework.
static void	setTimerExecutorService(ExecutorService timerExecutorService)	Sets the executor service used for executing timers.
static String	simpleClassName(Class<?> clazz)	Returns the simple name of a class.
static String	simpleObjectName(Object object)	Returns the simple name of the object’s class together with an id (see objectId(Object)).
static void	start(ComponentType application)	Fires a Start event with an associated Started completion event on the broadcast channel of the given application and wait for the completion of the Start event.
static ExecutorService	timerExecutorService()	Returns the executor service used for executing timers.
static boolean	useVirtualThreads()	JGrapes uses virtual thread by default.

Methods inherited from class java.lang.Object

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

Method Details

useVirtualThreads

public static boolean useVirtualThreads()

JGrapes uses virtual thread by default.

However, as of 2024, some debuggers still have problems with virtual threads. Therefore it is possible to switch back to platform threads by starting the JVM with property -Djgrapes.useVirtualThreads=false.

Returns:

true, if successful

defaultExecutorService

public static ExecutorService defaultExecutorService()

Return the default executor service for the framework.

Returns:

the defaultExecutorService

setDefaultExecutorService

public static void setDefaultExecutorService(ExecutorService defaultExecutorService)

Set the default executor service for the framework.

The default value is a cached thread pool (see @link Executors.newCachedThreadPool()) with daemon threads.

Parameters:

defaultExecutorService - the executor service to set

manager

public static Manager manager(ComponentType component)

Returns a component’s manager.

For a component that inherits from Component this method simply returns the component as it is its own manager.

For components that implement ComponentType but don’t inherit from Component the method returns the value of the attribute annotated as manager slot. If this attribute is still empty, this method makes the component the root of a new tree and returns its manager.

Parameters:

component - the component

Returns:

the component (with its manager attribute set)

manager

public static Manager manager(ComponentType component,
 Channel componentChannel)

Returns a component’s manager like manager(ComponentType).

If the manager slot attribute is empty, the component is initialized with its component channel set to the given parameter. Invoking this method overrides any channel set in the ComponentManager annotation.

This method is usually invoked by the constructor of a class that implements ComponentType.

Parameters:

component - the component

componentChannel - the channel that the component’s handlers listen on by default and that Manager.fire(Event, Channel...) sends the event to

Returns:

the component (with its manager attribute set)

See Also:

• Component(Channel)

start

public static void start(ComponentType application)
                  throws InterruptedException

Fires a Start event with an associated Started completion event on the broadcast channel of the given application and wait for the completion of the Start event.

Parameters:

application - the application to start

Throws:

InterruptedException - if the execution was interrupted

awaitExhaustion

public static void awaitExhaustion()
                            throws InterruptedException

Wait until all generators and event queues are exhausted.

When this stage is reached, nothing can happen anymore unless a new event is sent from an external thread.

Throws:

InterruptedException - if the current thread was interrupted while waiting

awaitExhaustion

public static boolean awaitExhaustion(long timeout)
                               throws InterruptedException

Wait until all generators and event queues are exhausted or the maximum wait time has expired.

Parameters:

timeout - the wait time in milliseconds

Returns:

true if exhaustion state was reached

Throws:

InterruptedException - if the execution was interrupted

See Also:

• awaitExhaustion()

checkAssertions

public static void checkAssertions()

Utility method that checks if an assertion error has occurred while executing handlers.

If so, the error is thrown and the assertion error store is reset.

This method is intended for junit tests. It enables easy propagation of assertion failures to the main thread.

Throws:

AssertionError - if an assertion error occurred while executing the application

fullObjectName

public static String fullObjectName(Object object)

Returns the full name of the object’s class together with an id (see objectId(Object)).

The result can be used as a unique human readable identifier for arbitrary objects.

Parameters:

object - the object

Returns:

the object’s name

simpleObjectName

public static String simpleObjectName(Object object)

Returns the simple name of the object’s class together with an id (see objectId(Object)).

Can be used to create a human readable, though not necessarily unique, label for an object.

Parameters:

object - the object

Returns:

the object’s name

objectName

public static String objectName(Object object)

Returns the name of the object’s class together with an id (see objectId(Object)).

May be used to implement toString() with identifiable objects. If the log level is “finer”, the full class name will be used for the returned value, else the simple name.

Parameters:

object - the object

Returns:

the object’s name

className

public static String className(Class<?> clazz)

Returns the full name or simple name of the class depending on the log level.

Parameters:

clazz - the class

Returns:

the name

simpleClassName

public static String simpleClassName(Class<?> clazz)

Returns the simple name of a class.

Contrary to Class.getSimpleName(), this method returns the last segement of the full name for anonymous classes (instead of an empty string).

Parameters:

clazz - the class

Returns:

the name

objectId

public static String objectId(Object object)

Returns an id of the object that is unique within a specific scope.

Ids are generated and looked up in the scope of the object’s class unless the class implements Components.IdInfoProvider.

Parameters:

object - the object

Returns:

the object’s name

timerExecutorService

public static ExecutorService timerExecutorService()

Returns the executor service used for executing timers.

Returns:

the timer executor service

setTimerExecutorService

public static void setTimerExecutorService(ExecutorService timerExecutorService)

Sets the executor service used for executing timers.

Defaults to the defaultExecutorService().

Parameters:

timerExecutorService - the timerExecutorService to set

schedule

public static Components.Timer schedule(Components.TimeoutHandler timeoutHandler,
 Instant scheduledFor)

Schedules the given timeout handler for the given instance.

Parameters:

timeoutHandler - the handler

scheduledFor - the instance in time

Returns:

the timer

schedule

public static Components.Timer schedule(Components.TimeoutHandler timeoutHandler,
 Duration scheduledFor)

Schedules the given timeout handler for the given offset from now.

Parameters:

timeoutHandler - the handler

scheduledFor - the time to wait

Returns:

the timer

put

public static <K,
V> Map<K,V> put(Map<K,V> map,
 K key,
 V value)

Puts the given key and value in the given Map and returns the map.

Looks ugly when nested, but comes in handy sometimes.

Type Parameters:

K - the key type

V - the value type

Parameters:

map - the map

key - the key

value - the value

Returns:

the map

mapOf

@Deprecated
public static <K,
V> Map<K,V> mapOf()

Deprecated.

Provisional replacement for method available in Java 9.

Returns:

an empty map

mapOf

@Deprecated
public static <K,
V> Map<K,V> mapOf(K k1,
 V v1)

Deprecated.

Provisional replacement for method available in Java 9.

Returns:

an immutable map filled with the given values

mapOf

@Deprecated
public static <K,
V> Map<K,V> mapOf(K k1,
 V v1,
 K k2,
 V v2)

Deprecated.

Provisional replacement for method available in Java 9.

Returns:

an immutable map filled with the given values

mapOf

@Deprecated
public static <K,
V> Map<K,V> mapOf(K k1,
 V v1,
 K k2,
 V v2,
 K k3,
 V v3)

Deprecated.

Provisional replacement for method available in Java 9.

Returns:

an immutable map filled with the given values

mapOf

@Deprecated
public static <K,
V> Map<K,V> mapOf(K k1,
 V v1,
 K k2,
 V v2,
 K k3,
 V v3,
 K k4,
 V v4)

Deprecated.

Provisional replacement for method available in Java 9.

Returns:

an immutable map filled with the given values

mapOf

@Deprecated
public static <K,
V> Map<K,V> mapOf(K k1,
 V v1,
 K k2,
 V v2,
 K k3,
 V v3,
 K k4,
 V v4,
 K k5,
 V v5)

Deprecated.

Provisional replacement for method available in Java 9.

Returns:

an immutable map filled with the given values

mapOf

@Deprecated
public static <K,
V> Map<K,V> mapOf(K k1,
 V v1,
 K k2,
 V v2,
 K k3,
 V v3,
 K k4,
 V v4,
 K k5,
 V v5,
 K k6,
 V v6)

Deprecated.

Provisional replacement for method available in Java 9.

Returns:

an immutable map filled with the given values

mapOf

@Deprecated
public static <K,
V> Map<K,V> mapOf(K k1,
 V v1,
 K k2,
 V v2,
 K k3,
 V v3,
 K k4,
 V v4,
 K k5,
 V v5,
 K k6,
 V v6,
 K k7,
 V v7)

Deprecated.

Provisional replacement for method available in Java 9.

Returns:

an immutable map filled with the given values

mapOf

@Deprecated
public static <K,
V> Map<K,V> mapOf(K k1,
 V v1,
 K k2,
 V v2,
 K k3,
 V v3,
 K k4,
 V v4,
 K k5,
 V v5,
 K k6,
 V v6,
 K k7,
 V v7,
 K k8,
 V v8)

Deprecated.

Provisional replacement for method available in Java 9.

Returns:

an immutable map filled with the given values

mapOf

@Deprecated
public static <K,
V> Map<K,V> mapOf(K k1,
 V v1,
 K k2,
 V v2,
 K k3,
 V v3,
 K k4,
 V v4,
 K k5,
 V v5,
 K k6,
 V v6,
 K k7,
 V v7,
 K k8,
 V v8,
 K k9,
 V v9)

Deprecated.

Provisional replacement for method available in Java 9.

Returns:

an immutable map filled with the given values

mapOf

@Deprecated
public static <K,
V> Map<K,V> mapOf(K k1,
 V v1,
 K k2,
 V v2,
 K k3,
 V v3,
 K k4,
 V v4,
 K k5,
 V v5,
 K k6,
 V v6,
 K k7,
 V v7,
 K k8,
 V v8,
 K k9,
 V v9,
 K k10,
 V v10)

Deprecated.

Provisional replacement for method available in Java 9.

Returns:

an immutable map filled with the given values