org.gonn.gava

Class Box<T>

java.lang.Object

org.gonn.gava.Box<T>

Type Parameters:

T - Type of the content to be boxed

All Implemented Interfaces:

AutoCloseable

public class Box<T>
extends Object
implements AutoCloseable

Box an object just like the java.util.Optional

Version:

0.0.5

Author:

Gon Yi

Constructor Summary

Constructors

Constructor and Description
Box(T t) Box object with T in it.

Method Summary

Modifier and Type	Method and Description
void	close()
Box<T>	eval(Fx10<T> evalFn) Evaluate the value regardless of whether the box is empty or not.
T	get() Get the box content.
T	get(T fallback) Get the box content.
boolean	isEmpty() Check if the box content is NULL.
boolean	isFull() Check if the box content is NOT NULL.
<R> Box<R>	map(Fx11<T,R> mapFn) Converts box content to a new content in a box.
static <T> Box<T>	of(T obj) Static constructor:
Box<T>	or(Runnable r) If the box is empty, execute the Runnable.
Box<T>	orSet(Fx01<T> valueFn) If the box is empty, returns the box with a new value
Box<T>	set(Fx01<T> setFn) Regardless of the box's state (whether full or not), set the content of the box.
Box<T>	skip(Fx11b<T> skipFn) If the condition function returns true, empty the box.
Box<T>	then(Fx10<T> modFn) View or modifying the box content.
Box<T>	thenSet(Fx11<T,T> modFn) Replace the box content.
String	toString()
<X extends Throwable> Box<T>	validate(Fx11b<T> validationFn, X throwable) Validate the box with validation function.

Methods inherited from class java.lang.Object

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

Constructor Detail

Box

public Box(T t)

Box object with T in it.

Parameters:

t - Boxed T.

Method Detail

of

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

Static constructor:

Type Parameters:

T - Type of the target object.

Parameters:

obj - A target object to be boxed.

Returns:

Boxed target object.

isEmpty

public boolean isEmpty()

Check if the box content is NULL.

Returns:

true if the content is NULL.

isFull

public boolean isFull()

Check if the box content is NOT NULL.

Returns:

true if the content is full.

get

public T get()

Get the box content. When the box is empty, this will return null.

Returns:

Content of the box.

get

public T get(T fallback)

Get the box content. If it is null, return the fallback instead.

Parameters:

fallback - A value to be returned when the box is empty.

Returns:

Content of the box.

skip

public Box<T> skip(Fx11b<T> skipFn)

If the condition function returns true, empty the box.

Parameters:

skipFn - A lambda function returning true means empty the box.

Returns:

Self

then

public Box<T> then(Fx10<T> modFn)

View or modifying the box content. This is for a mutable content. Use thenSet() for immutable content.

Parameters:

modFn - A function that can view or modify the content.

Returns:

self

thenSet

public Box<T> thenSet(Fx11<T,T> modFn)

Replace the box content. This is to replace the immutable content in a box. Content of the box will be replaced with the output of modFn. NOTE: This is between same content type. Use "map" method in order to change to a different type.

Parameters:

modFn - A function that takes and returns type T data.

Returns:

self

or

public Box<T> or(Runnable r)

If the box is empty, execute the Runnable.

Parameters:

r - A runnable to be executed. Since the box is empty, it won't do anything to the box. To modify the box, use orSet instead.

Returns:

Self

orSet

public Box<T> orSet(Fx01<T> valueFn)

If the box is empty, returns the box with a new value

Parameters:

valueFn - A function that returns new value for the box.

Returns:

Self

eval

public Box<T> eval(Fx10<T> evalFn)

Evaluate the value regardless of whether the box is empty or not.

Parameters:

evalFn - A lambda function to evaluate the value. This does not return anything.

Returns:

Self

validate

public <X extends Throwable> Box<T> validate(Fx11b<T> validationFn,
                                             X throwable)
                                      throws X extends Throwable

Validate the box with validation function. This will validate regardless of box's state. If the validation function couldn't validate the content of box, it will throw the throwable.

Type Parameters:

X - Any throwable types

Parameters:

validationFn - A function validating the value. Returns true if validated.

throwable - A throwable or an exception to be thrown if didn't get validated.

Returns:

Self

Throws:

X - Throwable if didn't get validated

X extends Throwable

set

public Box<T> set(Fx01<T> setFn)

Regardless of the box's state (whether full or not), set the content of the box.

Parameters:

setFn - A function returning new value

Returns:

A box with new value.

map

public <R> Box<R> map(Fx11<T,R> mapFn)

Converts box content to a new content in a box.

Type Parameters:

R - New return type

Parameters:

mapFn - Lambda function which takes current content, and returns a Box with new type of content.

Returns:

new boxed R.

toString

public String toString()

Overrides:

toString in class Object

close

public void close()

Specified by:

close in interface AutoCloseable