org.dbflute.optional

インタフェース OptionalThing<THING>

型パラメータ:

THING - The type of thing.

既知の実装クラスのリスト:

BaseOptional, OptionalEntity, OptionalObject, OptionalScalar

public interface OptionalThing<THING>

導入されたバージョン:

1.0.5F (2014/05/05 Monday)

作成者:

jflute

メソッドのサマリー

修飾子とタイプ	メソッドと説明
void	alwaysPresent(OptionalThingConsumer<THING> oneArgLambda) Handle the thing in the optional thing or exception if not present.
static <EMPTY> OptionalThing<EMPTY>	empty()
OptionalThing<THING>	filter(OptionalThingPredicate<THING> oneArgLambda) Filter the thing by the predicate.
<RESULT> OptionalThing<RESULT>	flatMap(OptionalThingFunction<? super THING,OptionalThing<RESULT>> oneArgLambda) Apply the flat-mapping of thing to result thing.
THING	get() Get the thing or exception if null.
OptionalThingIfPresentAfter	ifPresent(OptionalThingConsumer<THING> oneArgLambda) Handle the wrapped thing if it is present.
boolean	isPresent() Is the object instance present?
<RESULT> OptionalThing<RESULT>	map(OptionalThingFunction<? super THING,? extends RESULT> oneArgLambda) Apply the mapping of thing to result thing.
static <THING> OptionalThing<THING>	of(THING object)
static <THING> OptionalThing<THING>	ofNullable(THING object, OptionalThingExceptionThrower noArgLambda)
THING	orElse(THING other) Get the wrapped instance or returns the specified thing.
THING	orElseGet(OptionalThingSupplier<THING> noArgLambda) Get the thing or get from the supplier.
THING	orElseNull() 非推奨です。 basically use ifPresent() or use orElse(null)
<CAUSE extends Throwable> THING	orElseThrow(OptionalThingSupplier<? extends CAUSE> supplier) Get the thing or throw the exception.
Optional<THING>	toOptional() Convert to Java standard optional class.

メソッドの詳細

empty

static <EMPTY> OptionalThing<EMPTY> empty()

型パラメータ:

EMPTY - The type of empty optional thing.

戻り値:

The fixed instance as empty. (NotNull)

of

static <THING> OptionalThing<THING> of(THING object)

型パラメータ:

THING - The type of thing wrapped in the optional thing.

パラメータ:

object - The wrapped thing which is optional. (NotNull)

戻り値:

The new-created instance as existing optional thing. (NotNull)

ofNullable

static <THING> OptionalThing<THING> ofNullable(THING object,
                                               OptionalThingExceptionThrower noArgLambda)

型パラメータ:

THING - The type of thing wrapped in the optional thing.

パラメータ:

object - The wrapped instance or thing. (NullAllowed)

noArgLambda - The callback for exception when illegal access. (NotNull)

戻り値:

The new-created instance as existing or empty optional thing. (NotNull)

ifPresent

OptionalThingIfPresentAfter ifPresent(OptionalThingConsumer<THING> oneArgLambda)

Handle the wrapped thing if it is present.
You should call this if null object handling is unnecessary (do nothing if null).
If exception is preferred when null object, use required().

パラメータ:

oneArgLambda - The callback interface to consume the optional thing. (NotNull)

戻り値:

The handler of after process when if not present. (NotNull)

isPresent

boolean isPresent()

Is the object instance present? (existing?)

戻り値:

The determination, true or false.

get

THING get()

Get the thing or exception if null.

戻り値:

The instance of the wrapped thing. (NotNull)

例外:

EntityAlreadyDeletedException - When the object instance wrapped in this optional thing is null, which means object has already been deleted (point is not found).

filter

OptionalThing<THING> filter(OptionalThingPredicate<THING> oneArgLambda)

Filter the thing by the predicate.

パラメータ:

oneArgLambda - The callback to predicate whether the object is remained. (NotNull)

戻り値:

The filtered optional thing, might be empty. (NotNull)

map

<RESULT> OptionalThing<RESULT> map(OptionalThingFunction<? super THING,? extends RESULT> oneArgLambda)

Apply the mapping of thing to result thing.

型パラメータ:

RESULT - The type of mapping result.

パラメータ:

oneArgLambda - The callback interface to apply, null return allowed as empty. (NotNull)

戻り値:

The optional thing as mapped result. (NotNull, EmptyOptionalAllowed: if not present or callback returns null)

flatMap

<RESULT> OptionalThing<RESULT> flatMap(OptionalThingFunction<? super THING,OptionalThing<RESULT>> oneArgLambda)

Apply the flat-mapping of thing to result thing.

型パラメータ:

RESULT - The type of mapping result.

パラメータ:

oneArgLambda - The callback interface to apply, cannot return null. (NotNull)

戻り値:

The optional thing as mapped result. (NotNull, EmptyOptionalAllowed: if not present or callback returns null)

orElse

THING orElse(THING other)

Get the wrapped instance or returns the specified thing.

パラメータ:

other - The object instance to be returned when the optional is empty. (NullAllowed)

戻り値:

The wrapped instance or specified other object. (NullAllowed:)

orElseGet

THING orElseGet(OptionalThingSupplier<THING> noArgLambda)

Get the thing or get from the supplier.

パラメータ:

noArgLambda - The supplier of other instance if null. (NotNull)

戻り値:

The object instance wrapped in this optional thing or specified value. (NullAllowed: if null specified)

orElseThrow

<CAUSE extends Throwable> THING orElseThrow(OptionalThingSupplier<? extends CAUSE> supplier)
                                     throws CAUSE extends Throwable

Get the thing or throw the exception.

型パラメータ:

CAUSE - The type of cause.

パラメータ:

supplier - The supplier of exception if null. (NotNull)

戻り値:

The object instance wrapped in this optional object. (NotNull: if null, exception)

例外:

CAUSE - When the value is null.

CAUSE extends Throwable

toOptional

Optional<THING> toOptional()

Convert to Java standard optional class.
For only when standard optional handling is needed, so basically you don't use this.

戻り値:

The new-created instance or empty. (NotNull)

alwaysPresent

void alwaysPresent(OptionalThingConsumer<THING> oneArgLambda)

Handle the thing in the optional thing or exception if not present.

パラメータ:

oneArgLambda - The callback interface to consume the optional thing. (NotNull)

例外:

EntityAlreadyDeletedException - When the object instance wrapped in this optional thing is null, which means object has already been deleted (point is not found).

orElseNull

THING orElseNull()

非推奨です。 basically use ifPresent() or use orElse(null)

Get the object instance or null if not present.
basically use ifPresent() if might be not present, this is for emergency

戻り値:

The object instance wrapped in this optional thing or null. (NullAllowed: if not present)