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, @NotNull Class<T> aClass) Should be used for casting down the hierarchy of classes.
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.
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
static <R> Function<Object,R>	reinterpret(@NotNull Class<R> aClass) Returns a Function that narrows supplied arguments.
static <T> T	reinterpret(@Nullable Object o, @NotNull Class<T> aClass) Narrows the given Object to the type of the Class.
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.
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.
static <T> T	to(@Nullable Object o, @NotNull 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
                                          @Nullable Object o,
                                          @NotNull
                                          @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
                                                          @NotNull Class<R> aClass)

Returns a Function that narrows supplied arguments.

to

@Nullable
public static <T> T to(@Nullable
                                 @Nullable Object o,
                                 @NotNull
                                 @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
                                                 @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
                                         @NotNull Iterable<?> iterable,
                                         @NotNull
                                         @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
                                                         @NotNull Iterable<X> iterable,
                                                         @NotNull
                                                         @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
                                       @NotNull Stream<X> stream,
                                       @NotNull
                                       @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
                                                     @NotNull Stream<X> stream,
                                                     @NotNull
                                                     @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