Package overit.geocall.platform

Class ClassInstances<T>

java.lang.Object

overit.geocall.platform.ClassInstances<T>

Type Parameters:

T - type of registered objects

public class ClassInstances<T>
extends Object

The purpose of this class is to allow a set of objects to be recorded, and then to be able to recover by a name, that uniquely identifies the instance, or by the java class to which it belongs. Duplicate names are not allowed. However, it is possible to register instances of the same class, but with different names. In this case, be careful when invoking the get(Class) method because, since there are several instances registered with the same class, it will not be possible to distinguish them by class, and therefore an exception will be raised.

Field Summary

Fields

Modifier and Type	Field	Description
protected final ConcurrentHashMap<Class<?>,Optional<T>>	classes
protected final ConcurrentHashMap<String,T>	names

Constructor Summary

Constructors

Constructor	Description
ClassInstances()

Method Summary

Modifier and Type	Method	Description
T	get(Class<?> cls)	Returns the class instance from the class object under which it was registered.
T	get(String name)	Returns the class instance from the name under which it was registered.
void	register(String name, T instance)	Register a new instance by associating it with a certain name.
protected void	register(String name, T instance, Function<T,Class<?>> classExtractor)
protected void	unregisterAll()
Collection<T>	values()

Methods inherited from class java.lang.Object

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

Field Details

classes

protected final ConcurrentHashMap<Class<?>,Optional<T>> classes

names

protected final ConcurrentHashMap<String,T> names

Constructor Details

ClassInstances

public ClassInstances()

Method Details

register

public void register(String name,
 T instance)

Register a new instance by associating it with a certain name.

Parameters:

name - name that uniquely identifies the instance

instance - instance of the object to be registered

Throws:

IllegalArgumentException - if there is already an instance registered under the same name

register

protected void register(String name,
 T instance,
 Function<T,Class<?>> classExtractor)

unregisterAll

protected void unregisterAll()

get

public T get(String name)

Returns the class instance from the name under which it was registered. If there is no instance registered to that name, a null value is returned

Parameters:

name - the instance's name

Returns:

the class instance or null if there's no instances registered with the passed name.

get

public T get(Class<?> cls)

Returns the class instance from the class object under which it was registered. If there is no instance registered to that class, a null value is returned.

Parameters:

cls - the instance's class

Returns:

the class instance or null if there's no instances registered with the passed class.

Throws:

IllegalArgumentException - if several instances of the same class have been registered

values

public Collection<T> values()

Returns:

all registered instances