OptionalThing (DBFlute Runtime 1.2.5 API)

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

すべてのメソッド staticメソッドインスタンス・メソッド abstractメソッドデフォルト・メソッド
修飾子とタイプ	メソッドと説明
`void`	`alwaysPresent(OptionalThingConsumer<? super THING> oneArgLambda)` Handle the thing in the optional thing or (detail message) exception if not present.
`static <EMPTY> OptionalThing<EMPTY>`	`empty()`
`OptionalThing<THING>`	`filter(OptionalThingPredicate<? super 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 (detail message) exception if not present.
`OptionalThingIfPresentAfter`	`ifPresent(OptionalThingConsumer<? super THING> oneArgLambda)` Handle the wrapped thing if it is present.
`void`	`ifPresentOrElse(OptionalThingConsumer<? super THING> 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 THING,? extends RESULT> oneArgLambda)` Apply the mapping of thing to result thing.
`static <THING> OptionalThing<THING>`	`migratedFrom(Optional<THING> java8opt, OptionalThingExceptionThrower noArgLambda)`
`static <THING> OptionalThing<THING>`	`of(THING object)`
`static <THING> OptionalThing<THING>`	`ofNullable(THING object, OptionalThingExceptionThrower noArgLambda)`
`OptionalThing<THING>`	`or(OptionalThingSupplier<? extends OptionalThing<? extends THING>> noArgLambda)` Switch this to other optional if not present.
`THING`	`orElse(THING other)` Get the wrapped instance or returns the specified thing.
`THING`	`orElseGet(OptionalThingSupplier<? extends THING> noArgLambda)` Get the thing or get from the supplier.
`THING`	`orElseThrow()` Get the thing or throw the embedded exception.
`<CAUSE extends Throwable> THING`	`orElseThrow(OptionalThingSupplier<? extends CAUSE> noArgLambda)` Get the thing or throw the exception.
`<CAUSE extends Throwable,TRANSLATED extends Throwable> THING`	`orElseTranslatingThrow(OptionalThingFunction<CAUSE,TRANSLATED> causeLambda)` Get the thing or throw the exception with translating the cause.
`Stream<THING>`	`stream()` Handle the optional thing as stream.
`Optional<THING>`	`toOptional()` Convert to Java standard optional class.
`static <THING> OptionalThing<THING>`	`translatedFrom(OptionalThing<THING> dfopt, OptionalThingExceptionThrower noArgLambda)`

- 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)
  - migratedFrom
```
static <THING> OptionalThing<THING> migratedFrom(Optional<THING> java8opt,
                                                 OptionalThingExceptionThrower noArgLambda)
```
    型パラメータ:
    
    THING - The type of thing wrapped in the optional thing.
    
    パラメータ:
    
    java8opt - The optional instance as Java8 standard optional. (NotNull)
    
    noArgLambda - The callback for exception when illegal access. (NotNull)
    
    戻り値:
    
    The new-created instance as existing or empty optional thing. (NotNull)
  - translatedFrom
```
static <THING> OptionalThing<THING> translatedFrom(OptionalThing<THING> dfopt,
                                                   OptionalThingExceptionThrower noArgLambda)
```
    型パラメータ:
    
    THING - The type of thing wrapped in the optional thing.
    
    パラメータ:
    
    dfopt - The optional instance as optional thing DBFlute provides. (NotNull)
    
    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<? super THING> 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
```
void ifPresentOrElse(OptionalThingConsumer<? super THING> 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
```
boolean isPresent()
```
    Is the object instance present? (existing?)
    
    戻り値:
    
    The determination, true or false.
  - isEmpty
```
boolean isEmpty()
```
    Is the object instance empty? (not existing?)
    
    戻り値:
    
    The determination, true or false.
  - get
```
THING get()
```
    Get the thing or (detail message) exception if not present.
    
    戻り値:
    
    The instance of the wrapped thing. (NotNull)
    
    例外:
    
    RuntimeException - When not present, which means object is already deleted (not found).
  - or
```
OptionalThing<THING> or(OptionalThingSupplier<? extends OptionalThing<? extends THING>> 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
```
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<? extends THING> 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
```
THING 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)
    
    例外:
    
    RuntimeException - When not present, which means object is already deleted (not found).
  - orElseThrow
```
<CAUSE extends Throwable> THING 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
```
<CAUSE extends Throwable,TRANSLATED extends Throwable> THING 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
```
OptionalThing<THING> filter(OptionalThingPredicate<? super 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)
  - stream
```
Stream<THING> 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
```
void alwaysPresent(OptionalThingConsumer<? super THING> 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)
    
    例外:
    
    RuntimeException - When not present, which means object is already deleted (not found).
  - 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)

インタフェース OptionalThing<THING>

メソッドのサマリー

メソッドの詳細

empty

of

ofNullable

migratedFrom

translatedFrom

ifPresent

ifPresentOrElse

isPresent

isEmpty

get

or

orElse

orElseGet

orElseThrow

orElseThrow

orElseTranslatingThrow

filter

map

flatMap

stream

alwaysPresent

toOptional