The
orElseThrow() method of
java.util.Optional class in Java is used to get the value of this Optional instance if present. If there is no value present in this Optional instance, then this method throws the exception generated from the specified supplier.
Syntax:
public <X> T
orElseThrow(Supplier<X> exceptionSupplier)
throws X extends Throwable
Parameters: This method accepts
supplier as a parameter of type X to throws an exception if there is no value present in this Optional instance.
Return supplier: This method returns the
value of this Optional instance, if present. If there is no value present in this Optional instance, then this method throws the exception generated from the specified supplier.
Exception: This method throws
NullPointerException if there is no value present in this Optional instance.
Below programs illustrate orElseThrow() method:
Program 1:
Output:
Optional: Optional[9455]
Value by orElseThrow(ArithmeticException::new) method: 9455
Program 2:
