Package org.projecthusky.common.utils

Class OptionalUtils

java.lang.Object

org.projecthusky.common.utils.OptionalUtils

public class OptionalUtils
extends Object

Helper utilities related to Optionals.

Author:

Quentin Ligier

Method Summary

Modifier and Type	Method	Description
static <T> @Nullable T	castOrNull(Object object, Class<T> type)	Cast the given object to the required class or return null to filter the value in the Optional.
static <T> @Nullable T	getListElementAtIndex(List<T> list, int index)	Safe accessor to Lists that returns null instead of throwing IndexOutOfBoundsException.
static <T> @Nullable T	getListFirstElement(List<T> list)	Safe accessor to Lists that returns null instead of throwing IndexOutOfBoundsException.
static <T> @Nullable T	getListOnlyElement(List<T> list)	Safe accessor to Lists that returns null if the list contains no or multiple elements.

Methods inherited from class java.lang.Object

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

Method Details

getListElementAtIndex

public static <T> @Nullable T getListElementAtIndex(List<T> list,
 int index)

Safe accessor to Lists that returns null instead of throwing IndexOutOfBoundsException.

Type Parameters:

T - The type of the list content.

Parameters:

list - The list.

index - The index to access, positive or null.

Returns:

the value of the list at the requested index as type T or null.

getListFirstElement

public static <T> @Nullable T getListFirstElement(List<T> list)

Safe accessor to Lists that returns null instead of throwing IndexOutOfBoundsException.

Type Parameters:

T - The type of the list content.

Parameters:

list - The list.

Returns:

the first value of the list as type T or null.

getListOnlyElement

public static <T> @Nullable T getListOnlyElement(List<T> list)

Safe accessor to Lists that returns null if the list contains no or multiple elements.

Type Parameters:

T - The type of the list content.

Parameters:

list - The list.

Returns:

the only value of the list as type T or null.

castOrNull

public static <T> @Nullable T castOrNull(Object object,
 Class<T> type)

Cast the given object to the required class or return null to filter the value in the Optional.

Type Parameters:

T - The required type.

Parameters:

object - The instance to cast or filter.

type - The required type.

Returns:

the casted object or null if it wasn't an instance of the required type.