java.util

Class OptionalInt


  • public final class OptionalInt
extends Object
    A container object which may or may not contain a int value. If a value is present, isPresent() will return true and getAsInt() will return the value.

    Additional methods that depend on the presence or absence of a contained value are provided, such as orElse() (return a default value if value not present) and ifPresent() (execute a block of code if the value is present).

    This is a value-based class; use of identity-sensitive operations (including reference equality (==), identity hash code, or synchronization) on instances of OptionalInt may have unpredictable results and should be avoided.

    Since:
    1.8

    • Method Summary

      Modifier and Type Method and Description
      static OptionalInt empty()
      Returns an empty OptionalInt instance.
      boolean equals(Object obj)
      Indicates whether some other object is "equal to" this OptionalInt.
      int getAsInt()
      If a value is present in this OptionalInt, returns the value, otherwise throws NoSuchElementException.
      int hashCode()
      Returns the hash code value of the present value, if any, or 0 (zero) if no value is present.
      void ifPresent(IntConsumer consumer)
      Have the specified consumer accept the value if a value is present, otherwise do nothing.
      boolean isPresent()
      Return true if there is a value present, otherwise false.
      static OptionalInt of(int value)
      Return an OptionalInt with the specified value present.
      int orElse(int other)
      Return the value if present, otherwise return other.
      int orElseGet(IntSupplier other)
      Return the value if present, otherwise invoke other and return the result of that invocation.
      <X extends Throwable> int orElseThrow(Supplier<X> exceptionSupplier)
      Return the contained value, if present, otherwise throw an exception to be created by the provided supplier.
      String toString()
      Returns a string representation of the object.

    • Method Detail

      • empty

        public static OptionalInt empty()
        Returns an empty OptionalInt instance. No value is present for this OptionalInt.
        Returns:
        an empty OptionalInt

      • of

        public static OptionalInt of(int value)
        Return an OptionalInt with the specified value present.
        Parameters:
        value - the value to be present
        Returns:
        an OptionalInt with the value present

      • getAsInt

        public int getAsInt()
        If a value is present in this OptionalInt, returns the value, otherwise throws NoSuchElementException.
        Returns:
        the value held by this OptionalInt
        Throws:
        NoSuchElementException - if there is no value present
        See Also:
        isPresent()

      • isPresent

        public boolean isPresent()
        Return true if there is a value present, otherwise false.
        Returns:
        true if there is a value present, otherwise false

      • ifPresent

        public void ifPresent(IntConsumer consumer)
        Have the specified consumer accept the value if a value is present, otherwise do nothing.
        Parameters:
        consumer - block to be executed if a value is present
        Throws:
        NullPointerException - if value is present and consumer is null

      • orElse

        public int orElse(int other)
        Return the value if present, otherwise return other.
        Parameters:
        other - the value to be returned if there is no value present
        Returns:
        the value, if present, otherwise other

      • orElseGet

        public int orElseGet(IntSupplier other)
        Return the value if present, otherwise invoke other and return the result of that invocation.
        Parameters:
        other - a IntSupplier whose result is returned if no value is present
        Returns:
        the value if present otherwise the result of other.getAsInt()
        Throws:
        NullPointerException - if value is not present and other is null

      • orElseThrow

        public <X extends Throwable> int orElseThrow(Supplier<X> exceptionSupplier)
                                      throws X extends Throwable
        Return the contained value, if present, 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 there is no value present
        NullPointerException - if no value is present and exceptionSupplier is null
        X extends Throwable

      • equals

        public boolean equals(Object obj)
        Indicates whether some other object is "equal to" this OptionalInt. The other object is considered equal if:
        • it is also an OptionalInt and;
        • both instances have no value present or;
        • the present values are "equal to" each other via ==.
        Overrides:
        equals in class  Object
        Parameters:
        obj - an object to be tested for equality
        Returns:
        {code true} if the other object is "equal to" this object otherwise false
        See Also:
        Object.hashCode(), HashMap

      • toString

        public String toString()
        Returns a string representation of the object. In general, the toString method returns a string that "textually represents" this object. The result should be a concise but informative representation that is easy for a person to read. It is recommended that all subclasses override this method.

        The toString method for class Object returns a string consisting of the name of the class of which the object is an instance, the at-sign character `@', and the unsigned hexadecimal representation of the hash code of the object. In other words, this method returns a string equal to the value of: 

         getClass().getName() + '@' + Integer.toHexString(hashCode())
        Returns a non-empty string representation of this object suitable for debugging. The exact presentation format is unspecified and may vary between implementations and versions.
        Overrides:
        toString in class  Object
        Returns:
        the string representation of this instance