org.gonn.gava

Class Box<T>

java.lang.Object

org.gonn.gava.Box<T>

Type Parameters:

T -

public class Box<T>
extends Object

Box an object just like the java.util.Optional

Version:

0.0.1

Author:

Gon Yi

See Also:

Optional

Constructor Summary

Constructors

Constructor and Description
Box(T t)

Method Summary

Modifier and Type	Method and Description
boolean	equals(Object obj)
T	get() Get underlying value of the box.
T	get(T fallback) Get underlying value of the box.
int	hashCode()
boolean	isEmpty() If the box's underlying value is NULL.
boolean	isFull() If the box's underlying value is NOT NULL.
<R> Box<R>	map(java.util.function.Function<T,R> valueFunction) Map current underlying value of T into value of Box of R.
<R> Box<R>	map(java.util.function.Function<T,R> valueFunction, java.util.function.Supplier<R> fallbackSupplier) When valueFunction failed during map(), use output from fallbackSupplier()
static <T> Box<T>	of(T obj) Static constructor.
Box<T>	or(java.util.function.Supplier<T> fallbackSupplier) If not exists, function mod's value will be set for the value.
<X extends Throwable> Box<T>	orThrow(java.util.function.Supplier<? extends X> exceptionSupplier) If the Box is empty, throw an exception.
Box<T>	then(java.util.function.Consumer<T> valueConsumer) Run consumer mod.
Box<T>	update(java.util.function.UnaryOperator<T> valueOperator) Update will replace underlying T value.

Methods inherited from class java.lang.Object

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

Constructor Detail

Box

public Box(T t)

Method Detail

of

public static <T> Box<T> of(T obj)

Static constructor. Box.of("1123").map(v->v.length()).get()

Type Parameters:

T -

Parameters:

obj -

Returns:

Box of type T.

isEmpty

public boolean isEmpty()

If the box's underlying value is NULL.

Returns:

true if value is NULL.

isFull

public boolean isFull()

If the box's underlying value is NOT NULL.

Returns:

true if value is NOT NULL.

get

public T get()

Get underlying value of the box. When the box is empty, this will return null.

Returns:

get

public T get(T fallback)

Get underlying value of the box. However, if the box is empty, returns fallback of T.

Parameters:

fallback -

Returns:

content of T.

then

public Box<T> then(java.util.function.Consumer<T> valueConsumer)

Run consumer mod. Any modification should be done within the consumer. Box's value will not be changed. Use "update" method to change Box's value.

Parameters:

valueConsumer -

Returns:

update

public Box<T> update(java.util.function.UnaryOperator<T> valueOperator)

Update will replace underlying T value. Box's value will be changed within same value type. Use "map" method in order to change to a different type.

Parameters:

valueOperator -

Returns:

or

public Box<T> or(java.util.function.Supplier<T> fallbackSupplier)

If not exists, function mod's value will be set for the value. Box.of(new StringBuilder()).with(sb->sb.append("Hello")).map(sb->sb.size()).get()

Parameters:

fallbackSupplier -

Returns:

self

orThrow

public <X extends Throwable> Box<T> orThrow(java.util.function.Supplier<? extends X> exceptionSupplier)
                                     throws X extends Throwable

If the Box is empty, throw an exception.

Type Parameters:

X -

Parameters:

exceptionSupplier -

Returns:

self

Throws:

X - extends Throwable

X extends Throwable

map

public <R> Box<R> map(java.util.function.Function<T,R> valueFunction)

Map current underlying value of T into value of Box of R.

Type Parameters:

R - new type

Parameters:

valueFunction - modification function

Returns:

new boxed R.

map

public <R> Box<R> map(java.util.function.Function<T,R> valueFunction,
                      java.util.function.Supplier<R> fallbackSupplier)

When valueFunction failed during map(), use output from fallbackSupplier()

Type Parameters:

R - new type

Parameters:

valueFunction -

fallbackSupplier -

Returns:

new boxed R

hashCode

public int hashCode()

Overrides:

hashCode in class Object

equals

public boolean equals(Object obj)

Overrides:

equals in class Object