类的使用
com.github.jarvisframework.tool.core.lang.Optional

使用Optional的程序包

程序包	说明
com.github.jarvisframework.tool.core.lang

com.github.jarvisframework.tool.core.lang中Optional的使用

声明为Optional的com.github.jarvisframework.tool.core.lang中的字段

限定符和类型	字段和说明
private static Optional<?>	Optional.EMPTY Common instance for empty().

返回Optional的com.github.jarvisframework.tool.core.lang中的方法

限定符和类型	方法和说明
static <T> Optional<T>	Optional.empty() Returns an empty Optional instance.
Optional<T>	Optional.filter(java.util.function.Predicate<? super T> predicate) If a value is present, and the value matches the given predicate, return an Optional describing the value, otherwise return an empty Optional.
<U> Optional<U>	Optional.flatMap(java.util.function.Function<? super T,Optional<U>> mapper) If a value is present, apply the provided Optional-bearing mapping function to it, return that result, otherwise return an empty Optional.
<U> Optional<U>	Optional.map(java.util.function.Function<? super T,? extends U> mapper) If a value is present, apply the provided mapping function to it, and if the result is non-null, return an Optional describing the result.
static <T> Optional<T>	Optional.of(T value) Returns an Optional with the specified present non-null value.
static <T> Optional<T>	Optional.ofNullable(T value) Returns an Optional describing the specified value, if non-null, otherwise returns an empty Optional.

类型变量类型为Optional的com.github.jarvisframework.tool.core.lang中的方法参数

限定符和类型	方法和说明
<U> Optional<U>	Optional.flatMap(java.util.function.Function<? super T,Optional<U>> mapper) If a value is present, apply the provided Optional-bearing mapping function to it, return that result, otherwise return an empty Optional.