com.landawn.abacus.util

Class Holder<T>

java.lang.Object

com.landawn.abacus.util.Holder<T>

public final class Holder<T>
extends java.lang.Object

Since:

0.8

Author:

Haiyang Li

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	Holder.R<T>

Constructor Summary

Constructors

Constructor and Description
Holder()

Method Summary

Modifier and Type	Method and Description
<E extends java.lang.Exception> void	accept(Try.Consumer<? super T,E> action)
<E extends java.lang.Exception> void	acceptIfNotNull(Try.Consumer<? super T,E> action)
boolean	equals(java.lang.Object obj)
<E extends java.lang.Exception> Nullable<T>	filter(Try.Predicate<? super T,E> predicate)
<E extends java.lang.Exception> Nullable<T>	filterIfNotNull(Try.Predicate<? super T,E> predicate)
T	getAndSet(T value)
<E extends java.lang.Exception> T	getAndUpdate(Try.UnaryOperator<T,E> updateFunction)
T	getValue()
int	hashCode()
boolean	isNotNull()
<U,E extends java.lang.Exception> U	map(Try.Function<? super T,U,E> mapper)
<U,E extends java.lang.Exception> Nullable<U>	mapIfNotNull(Try.Function<? super T,U,E> mapper) Execute the specified action if value is not null, otherwise return null directly.
static <T> Holder<T>	of(T value)
<E extends java.lang.Exception> T	orGetIfNull(Try.Supplier<? extends T,E> other) Return the value is not null, otherwise invoke other and return the result of that invocation.
T	orIfNull(T other) Return the value is not null, otherwise return other.
<X extends java.lang.Throwable> T	orThrowIfNull(Supplier<? extends X> exceptionSupplier) Return the value is not null, otherwise throw an exception to be created by the provided supplier.
T	setAndGet(T value)
<E extends java.lang.Exception> boolean	setIf(T newValue, Try.BiPredicate<? super T,? super T,E> predicate) Set with the specified new value and returns true if predicate returns true.
<E extends java.lang.Exception> boolean	setIf(T newValue, Try.Predicate<? super T,E> predicate) Set with the specified new value and returns true if predicate returns true.
R	setValue(T value)
Stream<T>	stream()
Stream<T>	streamIfNotNull()
java.lang.String	toString()
<E extends java.lang.Exception> T	updateAndGet(Try.UnaryOperator<T,E> updateFunction)
T	value()

Methods inherited from class java.lang.Object

getClass, notify, notifyAll, wait, wait, wait

Constructor Detail

Holder

public Holder()

Method Detail

of

public static <T> Holder<T> of(T value)

value

public T value()

getValue

public T getValue()

setValue

public R setValue(T value)

getAndSet

public T getAndSet(T value)

setAndGet

public T setAndGet(T value)

getAndUpdate

public final <E extends java.lang.Exception> T getAndUpdate(Try.UnaryOperator<T,E> updateFunction)
                                                     throws E extends java.lang.Exception

Throws:

E extends java.lang.Exception

updateAndGet

public final <E extends java.lang.Exception> T updateAndGet(Try.UnaryOperator<T,E> updateFunction)
                                                     throws E extends java.lang.Exception

Throws:

E extends java.lang.Exception

setIf

public <E extends java.lang.Exception> boolean setIf(T newValue,
                                                     Try.Predicate<? super T,E> predicate)
                                              throws E extends java.lang.Exception

Set with the specified new value and returns true if predicate returns true. Otherwise just return false without setting the value to new value.

Parameters:

newValue -

predicate - - test the current value.

Returns:

Throws:

E extends java.lang.Exception

setIf

public <E extends java.lang.Exception> boolean setIf(T newValue,
                                                     Try.BiPredicate<? super T,? super T,E> predicate)
                                              throws E extends java.lang.Exception

Set with the specified new value and returns true if predicate returns true. Otherwise just return false without setting the value to new value.

Parameters:

newValue -

predicate - the first parameter is the current value, the second parameter is the new value.

Returns:

Throws:

E extends java.lang.Exception

isNotNull

public boolean isNotNull()

accept

public <E extends java.lang.Exception> void accept(Try.Consumer<? super T,E> action)
                                            throws E extends java.lang.Exception

Throws:

E extends java.lang.Exception

acceptIfNotNull

public <E extends java.lang.Exception> void acceptIfNotNull(Try.Consumer<? super T,E> action)
                                                     throws E extends java.lang.Exception

Throws:

E extends java.lang.Exception

map

public <U,E extends java.lang.Exception> U map(Try.Function<? super T,U,E> mapper)
                                        throws E extends java.lang.Exception

Throws:

E extends java.lang.Exception

mapIfNotNull

public <U,E extends java.lang.Exception> Nullable<U> mapIfNotNull(Try.Function<? super T,U,E> mapper)
                                                           throws E extends java.lang.Exception

Execute the specified action if value is not null, otherwise return null directly.

Parameters:

mapper -

Returns:

Throws:

E extends java.lang.Exception

filter

public <E extends java.lang.Exception> Nullable<T> filter(Try.Predicate<? super T,E> predicate)
                                                   throws E extends java.lang.Exception

Throws:

E extends java.lang.Exception

filterIfNotNull

public <E extends java.lang.Exception> Nullable<T> filterIfNotNull(Try.Predicate<? super T,E> predicate)
                                                            throws E extends java.lang.Exception

Throws:

E extends java.lang.Exception

stream

public Stream<T> stream()

streamIfNotNull

public Stream<T> streamIfNotNull()

Returns:

an empty Stream if the value is null.

orIfNull

public T orIfNull(T other)

Return the value is not null, otherwise return other.

Parameters:

other - the value to be returned if not present or null, may be null

Returns:

the value, if not present or null, otherwise other

orGetIfNull

public <E extends java.lang.Exception> T orGetIfNull(Try.Supplier<? extends T,E> other)
                                              throws E extends java.lang.Exception

Return the value is not null, otherwise invoke other and return the result of that invocation.

Parameters:

other - a Supplier whose result is returned if not present or null

Returns:

the value if not present or null otherwise the result of other.get()

Throws:

java.lang.NullPointerException - if value is not present and other is null

E extends java.lang.Exception

orThrowIfNull

public <X extends java.lang.Throwable> T orThrowIfNull(Supplier<? extends X> exceptionSupplier)
                                                throws X extends java.lang.Throwable

Return the value is not null, otherwise throw an exception to be created by the provided supplier.

Type Parameters:

X - Type of the exception to be thrown

Parameters:

exceptionSupplier - The supplier which will return the exception to be thrown

Returns:

the present value

Throws:

X - if not present or null

java.lang.NullPointerException - if not present or null and exceptionSupplier is null

X extends java.lang.Throwable

hashCode

public int hashCode()

Overrides:

hashCode in class java.lang.Object

equals

public boolean equals(java.lang.Object obj)

Overrides:

equals in class java.lang.Object

toString

public java.lang.String toString()

Overrides:

toString in class java.lang.Object