de.jstacs.io

Class ArrayHandler

java.lang.Object

de.jstacs.io.ArrayHandler

public final class ArrayHandler
extends Object

This class handles arrays with elements of generic type and enables the user to cast, clone, and create arrays easily.

Author:

Jens Keilwagen

Constructor Summary

Constructors

Constructor and Description
ArrayHandler()

Method Summary

Modifier and Type	Method and Description
static <S> S[]	cast(Class<? extends S> c, Object[] o) This method returns an array of a user-specified class with all elements in the given array o.
static Object[]	cast(Object[] o) This method creates a new array of the superclass of all elements of the given array and copies the elements.
static <T extends Cloneable> T[]	clone(T... t) This method returns a deep copy of a (multi-dimensional) array of Cloneables or primitives.
static <T extends Cloneable> T[]	createArrayOf(T t, int l) This method returns an array of length l that has at each position a clone of t.
static <T> Class	getSuperClassOf(T... o) This method returns the deepest class in the class hierarchy that is the class or a superclass of all instances in the array.

Methods inherited from class java.lang.Object

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

Constructor Detail

ArrayHandler

public ArrayHandler()

Method Detail

getSuperClassOf

public static <T> Class getSuperClassOf(T... o)

This method returns the deepest class in the class hierarchy that is the class or a superclass of all instances in the array.

Type Parameters:

T - the type of the array elements

Parameters:

o - the array

Returns:

the superclass of all elements of the given array

cast

public static Object[] cast(Object[] o)

This method creates a new array of the superclass of all elements of the given array and copies the elements. The order of the elements is not changed.

Here is an example that demonstrates what can be done:

Object[] o = { new UniformTrainSM( alphabetContainer ), new UniformTrainSM( alphabetContainer ) };
AbstractTrainableStatisticalModel[] a = (AbstractTrainableStatisticalModel[]) ArrayHandler.cast( o );

This should work fine, while
AbstractTrainableStatisticalModel[] a = (AbstractTrainableStatisticalModel[]) o;
will not.

Parameters:

o - the array

Returns:

the casted array with the copied elements

See Also:

getSuperClassOf(Object[]), cast(Class, Object[])

cast

public static <S> S[] cast(Class<? extends S> c,
                           Object[] o)

This method returns an array of a user-specified class with all elements in the given array o. If the given array is already from the correct class it is directly returned, otherwise a new array is created and filled with the elements of o. In both cases, the order of the elements is not changed.

Here is an example that demonstrates what can be done:

Object[] o = { new UniformTrainSM( alphabetContainer ), new UniformTrainSM( alphabetContainer ) };
AbstractTrainableStatisticalModel[] a = ArrayHandler.cast( AbstractTrainableStatisticalModel.class, o );

This should work fine, while
AbstractTrainableStatisticalModel[] a = (AbstractTrainableStatisticalModel[]) o;
will not.

Type Parameters:

S - the type of the array elements

Parameters:

c - the class of the array items

o - the array

Returns:

the casted array with the copied elements

See Also:

getSuperClassOf(Object[])

clone

public static <T extends Cloneable> T[] clone(T... t)
                                       throws CloneNotSupportedException

This method returns a deep copy of a (multi-dimensional) array of Cloneables or primitives. For arrays of Cloneables, each element of the array is cloned using its clone()-method.

Type Parameters:

T - the type of the array elements

Parameters:

t - the array

Returns:

a deep copy of the given array

Throws:

CloneNotSupportedException - if an element could not be cloned

See Also:

Cloneable

createArrayOf

public static <T extends Cloneable> T[] createArrayOf(T t,
                                                      int l)
                                               throws CloneNotSupportedException

This method returns an array of length l that has at each position a clone of t.

Type Parameters:

T - the type of the array elements that implements Cloneable

Parameters:

t - the original element

l - the dimension of the new array

Returns:

an array of length l that has at each position a clone of t

Throws:

CloneNotSupportedException - if t could not be cloned

See Also:

Cloneable