com.atlassian.bamboo.util

Class Narrow

java.lang.Object

com.atlassian.bamboo.util.Narrow

public class Narrow
extends Object

Utility for narrowing object instances to Class types See to(Object, Class)

Since:

2.7

Method Summary

Modifier and Type	Method and Description
static <X,T extends X> T	downTo(X o, Class<T> aClass) Should be used for casting down the hierarchy of classes.
static <X,T extends X> Iterable<T>	iterableDownTo(Iterable<X> iterable, Class<T> aClass) Filters given Iterable returning only these objects which could be narrowed to given type.
static <T> Iterable<T>	iterableTo(Iterable<?> iterable, Class<T> aClass) Filters given Iterable returning only these objects which could be narrowed to given type
static <R> Function<Object,R>	reinterpret(Class<R> aClass) Returns a Function that narrows supplied arguments.
static <T> T	reinterpret(Object o, Class<T> aClass) Narrows the given Object to the type of the Class.
static <X,T extends X> Stream<T>	streamDownTo(Stream<X> stream, Class<T> aClass) Filters given Stream returning only these objects which could be narrowed to given type.
static <X,T> Stream<T>	streamTo(Stream<X> stream, Class<T> aClass) Filters given Stream returning only these objects which could be narrowed to given type.
static <T> T	to(Object o, Class<T> aClass) Narrows the given Object to the type of the Class.

Methods inherited from class java.lang.Object

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

Method Detail

reinterpret

@Nullable
public static <T> T reinterpret(@Nullable
                                          Object o,
                                          @NotNull
                                          Class<T> aClass)

Narrows the given Object to the type of the Class. Using downTo(Object, Class) is always preferred over using this method. If object cannot be narrowed to the given type this method returns null This is a non-throwing form of Class.cast(Object)

Type Parameters:

T - the type to be narrowed to

Parameters:

o - the object to be narrowed. This object can be a null reference

aClass - the class to narrow to

Returns:

narrowed object

reinterpret

@NotNull
public static <R> Function<Object,R> reinterpret(@NotNull
                                                          Class<R> aClass)

Returns a Function that narrows supplied arguments.

to

@Nullable
public static <T> T to(@Nullable
                                 Object o,
                                 @NotNull
                                 Class<T> aClass)

Narrows the given Object to the type of the Class. Using downTo(Object, Class) is always preferred over using this method. If object cannot be narrowed to the given type this method returns null This is a non-throwing form of Class.cast(Object)

Type Parameters:

T - the type to be narrowed to

Parameters:

o - the object to be narrowed. This object can be a null reference

aClass - the class to narrow to

Returns:

narrowed object

downTo

@Nullable
public static <X,T extends X> T downTo(@Nullable
                                                 X o,
                                                 @NotNull
                                                 Class<T> aClass)

Should be used for casting down the hierarchy of classes. See to(Object, Class).

iterableTo

public static <T> Iterable<T> iterableTo(@NotNull
                                         Iterable<?> iterable,
                                         @NotNull
                                         Class<T> aClass)

Filters given Iterable returning only these objects which could be narrowed to given type

Type Parameters:

T -

Parameters:

iterable - input iterable containing elements to filter

aClass - class used to narrow elements of iterable

Returns:

filtered iterable with non-null elements narrowed to aClass

iterableDownTo

public static <X,T extends X> Iterable<T> iterableDownTo(@NotNull
                                                         Iterable<X> iterable,
                                                         @NotNull
                                                         Class<T> aClass)

Filters given Iterable returning only these objects which could be narrowed to given type. This version is more typesafe that iterableTo(Iterable, Class) and should be used when casting down the class structure. (e.g. List<ImmutablePlan> -> Iterable<ImmutableChain>)

Parameters:

iterable - input iterable containing elements to filter

aClass - class used to narrow elements of iterable

Returns:

filtered iterable with non-null elements narrowed to aClass

streamTo

public static <X,T> Stream<T> streamTo(@NotNull
                                       Stream<X> stream,
                                       @NotNull
                                       Class<T> aClass)

Filters given Stream returning only these objects which could be narrowed to given type.

Parameters:

stream - input iterable containing elements to filter

aClass - class used to narrow elements of iterable

Returns:

filtered iterable with non-null elements narrowed to aClass

streamDownTo

public static <X,T extends X> Stream<T> streamDownTo(@NotNull
                                                     Stream<X> stream,
                                                     @NotNull
                                                     Class<T> aClass)

Filters given Stream returning only these objects which could be narrowed to given type. This version is more typesafe that streamTo(Stream, Class) and should be used when casting down the class structure. (e.g. List<ImmutablePlan> -> Iterable<ImmutableChain>)

Parameters:

stream - input iterable containing elements to filter

aClass - class used to narrow elements of iterable

Returns:

filtered iterable with non-null elements narrowed to aClass