Apache Commons Collections 4.4 · org.apache.commons.collections4.FactoryUtils

Access	Constructor and Description
private	FactoryUtils() This class is not normally instantiated.

Method Summary

Modifier and Type	Method and Description
public static < the type that the factory creates T> Factory<T>	Returns: the `constant` factory. constantFactory(final T the constant object to return each time in the factory constantToReturn) Creates a Factory that will return the same object each time the factory is used.
public static < the type that the factory creates T> Factory<T>	Returns: the factory exceptionFactory() Gets a Factory that always throws an exception.
public static < the type that the factory creates T> Factory<T>	Returns: the `reflection` factory instantiateFactory(final Class<T> the Class to instantiate each time in the factory classToInstantiate) Creates a Factory that can create objects of a specific type using a no-args constructor.
public static < the type that the factory creates T> Factory<T>	Returns: the `reflection` factory instantiateFactory(final Class<T> the Class to instantiate each time in the factory classToInstantiate, final Class<?>[] parameter types for the constructor, can be null paramTypes, final Object[] the arguments to pass to the constructor, can be null args) Creates a Factory that can create objects of a specific type using the arguments specified to this method.
public static < the "type" of null object the factory should return. T> Factory<T>	Returns: the factory nullFactory() Gets a Factory that will return null each time the factory is used.
public static < the type that the factory creates T> Factory<T>	Returns: the `prototype` factory, or a `ConstantFactory#NULL_INSTANCE` if the `prototype` is `null` prototypeFactory(final T the object to clone each time in the factory prototype) Creates a Factory that will return a clone of the same prototype object each time the factory is used.

Inherited from java.lang.Object:: clone equals finalize getClass hashCode notify notifyAll toString wait wait wait

FactoryUtils	back to summary
private FactoryUtils() This class is not normally instantiated.

Method Detail

constantFactory back to summary

constantFactory	back to summary
public static <T> Factory<T> constantFactory(final T constantToReturn) Creates a Factory that will return the same object each time the factory is used. No check is made that the object is immutable. In general, only immutable objects should use the constant factory. Mutable objects should use the prototype factory. Parameters <T> the type that the factory creates constantToReturn:T the constant object to return each time in the factory Returns:Factory<T> the `constant` factory. See Also `org.apache.commons.collections4.functors.ConstantFactory`

public static <T> Factory<T> constantFactory(final T constantToReturn)

Creates a Factory that will return the same object each time the factory is used. No check is made that the object is immutable. In general, only immutable objects should use the constant factory. Mutable objects should use the prototype factory.

Parameters

<T>: the type that the factory creates
constantToReturn:T: the constant object to return each time in the factory

Returns:Factory<T>

the constant factory.

exceptionFactory back to summary

exceptionFactory	back to summary
public static <T> Factory<T> exceptionFactory() Gets a Factory that always throws an exception. This could be useful during testing as a placeholder. Parameters <T> the type that the factory creates Returns:Factory<T> the factory See Also `org.apache.commons.collections4.functors.ExceptionFactory`

public static <T> Factory<T> exceptionFactory()

Gets a Factory that always throws an exception. This could be useful during testing as a placeholder.

Parameters

<T>: the type that the factory creates

Returns:Factory<T>

the factory

instantiateFactory back to summary

instantiateFactory	back to summary
public static <T> Factory<T> instantiateFactory(final Class<T> classToInstantiate) Creates a Factory that can create objects of a specific type using a no-args constructor. Parameters <T> the type that the factory creates classToInstantiate:Class<T> the Class to instantiate each time in the factory Returns:Factory<T> the `reflection` factory Exceptions NullPointerException: if the classToInstantiate is null See Also `org.apache.commons.collections4.functors.InstantiateFactory`

public static <T> Factory<T> instantiateFactory(final Class<T> classToInstantiate)

Creates a Factory that can create objects of a specific type using a no-args constructor.

Parameters

<T>: the type that the factory creates
classToInstantiate:Class<T>: the Class to instantiate each time in the factory

Returns:Factory<T>

the reflection factory

Exceptions

NullPointerException:: if the classToInstantiate is null

instantiateFactory back to summary

instantiateFactory	back to summary
public static <T> Factory<T> instantiateFactory(final Class<T> classToInstantiate, final Class<?>[] paramTypes, final Object[] args) Creates a Factory that can create objects of a specific type using the arguments specified to this method. Parameters <T> the type that the factory creates classToInstantiate:Class<T> the Class to instantiate each time in the factory paramTypes:Class<?>[] parameter types for the constructor, can be null args:Object[] the arguments to pass to the constructor, can be null Returns:Factory<T> the `reflection` factory Exceptions NullPointerException: if the classToInstantiate is null IllegalArgumentException: if the paramTypes and args don't match if the constructor doesn't exist See Also `org.apache.commons.collections4.functors.InstantiateFactory`

public static <T> Factory<T> instantiateFactory(final Class<T> classToInstantiate, final Class<?>[] paramTypes, final Object[] args)

Creates a Factory that can create objects of a specific type using the arguments specified to this method.

Parameters

<T>: the type that the factory creates
classToInstantiate:Class<T>: the Class to instantiate each time in the factory
paramTypes:Class<?>[]: parameter types for the constructor, can be null
args:Object[]: the arguments to pass to the constructor, can be null

Returns:Factory<T>

the reflection factory

Exceptions

NullPointerException:

if the classToInstantiate is null

IllegalArgumentException:

if the paramTypes and args don't match
if the constructor doesn't exist

nullFactory back to summary

nullFactory	back to summary
public static <T> Factory<T> nullFactory() Gets a Factory that will return null each time the factory is used. This could be useful during testing as a placeholder. Parameters <T> the "type" of null object the factory should return. Returns:Factory<T> the factory See Also `org.apache.commons.collections4.functors.ConstantFactory`

public static <T> Factory<T> nullFactory()

Gets a Factory that will return null each time the factory is used. This could be useful during testing as a placeholder.

Parameters

<T>: the "type" of null object the factory should return.

Returns:Factory<T>

the factory

prototypeFactory back to summary

prototypeFactory	back to summary
public static <T> Factory<T> prototypeFactory(final T prototype) Creates a Factory that will return a clone of the same prototype object each time the factory is used. The prototype will be cloned using one of these techniques (in order): public clone method public copy constructor serialization clone Parameters <T> the type that the factory creates prototype:T the object to clone each time in the factory Returns:Factory<T> the `prototype` factory, or a `ConstantFactory#NULL_INSTANCE` if the `prototype` is `null` Exceptions IllegalArgumentException: if the prototype cannot be cloned See Also `org.apache.commons.collections4.functors.PrototypeFactory`

public static <T> Factory<T> prototypeFactory(final T prototype)

Creates a Factory that will return a clone of the same prototype object each time the factory is used. The prototype will be cloned using one of these techniques (in order):

public clone method
public copy constructor
serialization clone

Parameters

<T>: the type that the factory creates
prototype:T: the object to clone each time in the factory

Returns:Factory<T>

the prototype factory, or a ConstantFactory#NULL_INSTANCE if the prototype is null

Exceptions

IllegalArgumentException:: if the prototype cannot be cloned

public Class FactoryUtils

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Constructor Detail

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