org.dbflute.optional

クラス OptionalObject<OBJ>

java.lang.Object

org.dbflute.optional.BaseOptional<OBJ>

org.dbflute.optional.OptionalObject<OBJ>

型パラメータ:

OBJ - The type of object.

すべての実装されたインタフェース:

Serializable, OptionalThing<OBJ>

public class OptionalObject<OBJ>
extends BaseOptional<OBJ>

導入されたバージョン:

1.1.0-sp1 (2015/01/19 Monday)

作成者:

jflute

関連項目:

直列化された形式

フィールドのサマリー

フィールド

修飾子とタイプ	フィールドと説明
protected static OptionalObject<Object>	EMPTY_INSTANCE
protected static OptionalThingExceptionThrower	NOWAY_THROWER

クラスから継承されたフィールド org.dbflute.optional.BaseOptional

_obj, _thrower, IF_PRESENT_AFTER_EMPTY, IF_PRESENT_AFTER_NONE_FIRE

コンストラクタのサマリー

コンストラクタ

コンストラクタと説明
OptionalObject(OBJ thing, OptionalThingExceptionThrower thrower)

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<? super OBJ> oneArgLambda) Handle the thing in the optional thing or (detail message) exception if not present.
protected <ARG> OptionalObject<ARG>	createOptionalFilteredObject(ARG obj)
protected <ARG> OptionalObject<ARG>	createOptionalFlatMappedObject(ARG obj)
protected <ARG> OptionalObject<ARG>	createOptionalMappedObject(ARG obj)
static <EMPTY> OptionalObject<EMPTY>	empty()
OptionalObject<OBJ>	filter(OptionalThingPredicate<? super OBJ> oneArgLambda) Filter the thing by the predicate.
<RESULT> OptionalThing<RESULT>	flatMap(OptionalThingFunction<? super OBJ,OptionalThing<RESULT>> oneArgLambda) Apply the flat-mapping of thing to result thing.
OBJ	get() Get the thing or (detail message) exception if not present.
OptionalThingIfPresentAfter	ifPresent(OptionalThingConsumer<? super OBJ> oneArgLambda) Handle the wrapped thing if it is present.
void	ifPresentOrElse(OptionalThingConsumer<? super OBJ> oneArgLambda, IndependentProcessor noArgLambda) Handle the wrapped thing if it is both present and empty.
boolean	isEmpty() Is the object instance empty?
boolean	isPresent() Is the object instance present?
<RESULT> OptionalThing<RESULT>	map(OptionalThingFunction<? super OBJ,? extends RESULT> oneArgLambda) Apply the mapping of thing to result thing.
static <OBJ> OptionalObject<OBJ>	of(OBJ object)
static <OBJ> OptionalObject<OBJ>	ofNullable(OBJ object, OptionalThingExceptionThrower noArgLambda)
OptionalThing<OBJ>	or(OptionalThingSupplier<? extends OptionalThing<? extends OBJ>> noArgLambda) Switch this to other optional if not present.
OBJ	orElse(OBJ other) Get the wrapped instance or returns the specified thing.
OBJ	orElseGet(OptionalThingSupplier<? extends OBJ> noArgLambda) Get the thing or get from the supplier.
OBJ	orElseThrow() Get the thing or throw the embedded exception.
<CAUSE extends Throwable> OBJ	orElseThrow(OptionalThingSupplier<? extends CAUSE> noArgLambda) Get the thing or throw the exception.
<CAUSE extends Throwable,TRANSLATED extends Throwable> OBJ	orElseTranslatingThrow(OptionalThingFunction<CAUSE,TRANSLATED> causeLambda) Get the thing or throw the exception with translating the cause.
Stream<OBJ>	stream() Handle the optional thing as stream.

クラスから継承されたメソッド org.dbflute.optional.BaseOptional

assertCauseLambdaNotNull, assertNoArgLambdaNotNull, assertOneArgLambdaNotNull, callbackAlwaysPresent, callbackFilter, callbackFlatMapping, callbackGetOrElseGet, callbackGetOrElseThrow, callbackGetOrElseTranslatingThrow, callbackIfPresent, callbackIfPresentOrElse, callbackMapping, callbackOr, convertToStream, determineEmpty, determinePresent, directlyGet, directlyGetOrElse, equals, exists, hashCode, toOptional, toString

クラスから継承されたメソッド java.lang.Object

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

インタフェースから継承されたメソッド org.dbflute.optional.OptionalThing

migratedFrom, translatedFrom

フィールドの詳細

EMPTY_INSTANCE

protected static final OptionalObject<Object> EMPTY_INSTANCE

NOWAY_THROWER

protected static final OptionalThingExceptionThrower NOWAY_THROWER

コンストラクタの詳細

OptionalObject

public OptionalObject(OBJ thing,
                      OptionalThingExceptionThrower thrower)

パラメータ:

thing - The wrapped instance of thing. (NullAllowed)

thrower - The exception thrower when illegal access. (NotNull)

メソッドの詳細

empty

public static <EMPTY> OptionalObject<EMPTY> empty()

型パラメータ:

EMPTY - The type of empty optional object.

戻り値:

The fixed instance as empty. (NotNull)

of

public static <OBJ> OptionalObject<OBJ> of(OBJ object)

型パラメータ:

OBJ - The type of object wrapped in the optional object.

パラメータ:

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

戻り値:

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

ofNullable

public static <OBJ> OptionalObject<OBJ> ofNullable(OBJ object,
                                                   OptionalThingExceptionThrower noArgLambda)

型パラメータ:

OBJ - The type of object wrapped in the optional object.

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 object. (NotNull)

ifPresent

public OptionalThingIfPresentAfter ifPresent(OptionalThingConsumer<? super OBJ> oneArgLambda)

Handle the wrapped thing if it is present.
You should call this if empty handling is unnecessary (do nothing if not present).
If exception is preferred when null object, use alwaysPresent().

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)

ifPresentOrElse

public void ifPresentOrElse(OptionalThingConsumer<? super OBJ> oneArgLambda,
                            IndependentProcessor noArgLambda)

Handle the wrapped thing if it is both present and empty.

パラメータ:

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

noArgLambda - The empty-case callback interface to handle or-else. (NotNull)

isPresent

public boolean isPresent()

Is the object instance present? (existing?)

戻り値:

The determination, true or false.

isEmpty

public boolean isEmpty()

Is the object instance empty? (not existing?)

戻り値:

The determination, true or false.

get

public OBJ get()

Get the thing or (detail message) exception if not present.

戻り値:

The instance of the wrapped thing. (NotNull)

or

public OptionalThing<OBJ> or(OptionalThingSupplier<? extends OptionalThing<? extends OBJ>> noArgLambda)

Switch this to other optional if not present.

パラメータ:

noArgLambda - The supplier of other optional if not present. (NotNull)

戻り値:

this or optional provided by supplier. (NotNull, EmptyAllowed: provided one may be empty)

orElse

public OBJ orElse(OBJ 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

public OBJ orElseGet(OptionalThingSupplier<? extends OBJ> noArgLambda)

Get the thing or get from the supplier.

パラメータ:

noArgLambda - The supplier of other instance if not present. (NotNull)

戻り値:

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

orElseThrow

public OBJ orElseThrow()

Get the thing or throw the embedded exception.
Actually same as get(), similar to alwaysPresent().

戻り値:

The object instance wrapped in this optional object. (NotNull: if not present, exception)

orElseThrow

public <CAUSE extends Throwable> OBJ orElseThrow(OptionalThingSupplier<? extends CAUSE> noArgLambda)
                                          throws CAUSE extends Throwable

Get the thing or throw the exception.
However the orElseTranslatingThrow() is recommended instead this.

型パラメータ:

CAUSE - The type of cause.

パラメータ:

noArgLambda - The supplier of exception if not present. (NotNull)

戻り値:

The object instance wrapped in this optional object. (NotNull: if not present, exception)

例外:

CAUSE - When the value is null.

CAUSE extends Throwable

orElseTranslatingThrow

public <CAUSE extends Throwable,TRANSLATED extends Throwable> OBJ orElseTranslatingThrow(OptionalThingFunction<CAUSE,TRANSLATED> causeLambda)
                                                                                  throws TRANSLATED extends Throwable

Get the thing or throw the exception with translating the cause.

 OptionalThing<String> optSea = ...
 String sea = optSea.orElseTranslatingThrow(cause -> {
     return new YourBusinessException("...", cause); // you can wrap the detail exception
 }
 

型パラメータ:

CAUSE - The type of original cause.

TRANSLATED - The type of translated cause.

パラメータ:

causeLambda - The translator function of cause exception if not present, returning your exception. (NotNull)

戻り値:

The object instance wrapped in this optional object. (NotNull: if not present, exception)

例外:

TRANSLATED - When the value is null.

TRANSLATED extends Throwable

filter

public OptionalObject<OBJ> filter(OptionalThingPredicate<? super OBJ> 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)

createOptionalFilteredObject

protected <ARG> OptionalObject<ARG> createOptionalFilteredObject(ARG obj)

定義:

createOptionalFilteredObject クラス内 BaseOptional<OBJ>

型パラメータ:

ARG - The type of value for optional thing.

パラメータ:

obj - The plain object for the optional thing. (NullAllowed: if null, returns empty optional)

戻り値:

The new-created instance of optional thing. (NotNull)

map

public <RESULT> OptionalThing<RESULT> map(OptionalThingFunction<? super OBJ,? 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)

createOptionalMappedObject

protected <ARG> OptionalObject<ARG> createOptionalMappedObject(ARG obj)

定義:

createOptionalMappedObject クラス内 BaseOptional<OBJ>

型パラメータ:

ARG - The type of value for optional thing.

パラメータ:

obj - The plain object for the optional thing. (NullAllowed: if null, returns empty optional)

戻り値:

The new-created instance of optional thing. (NotNull)

flatMap

public <RESULT> OptionalThing<RESULT> flatMap(OptionalThingFunction<? super OBJ,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)

createOptionalFlatMappedObject

protected <ARG> OptionalObject<ARG> createOptionalFlatMappedObject(ARG obj)

定義:

createOptionalFlatMappedObject クラス内 BaseOptional<OBJ>

型パラメータ:

ARG - The type of value for optional thing.

パラメータ:

obj - The plain object for the optional thing. (NullAllowed: if null, returns empty optional)

戻り値:

The new-created instance of optional thing. (NotNull)

stream

public Stream<OBJ> stream()

Handle the optional thing as stream.

戻り値:

The stream for the optional thing, may be empty (if not present). (NotNull, EmptyAllowed: if not present)

alwaysPresent

public void alwaysPresent(OptionalThingConsumer<? super OBJ> oneArgLambda)

Handle the thing in the optional thing or (detail message) exception if not present.

 memberBhv.selectEntity(cb -> {
     cb.setupSelect_MemberStatus();
     cb.query().setMemberId_Equal(1);
 }).alwaysPresent(member -> { // called if value exists, or exception
     ... = member.getMemberName();
     member.getMemberStatus().alwaysPresent(status -> { // also relationship
         ... = status.getMemberStatusName();
     });
 });
 

パラメータ:

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