The orElseThrow(Supplier) method of OptionalDouble class used to get the value contained by OptionalDouble. If a value is present, this method returns the value, otherwise, this method throws an exception produced by the exception supplying function. The exception Supplier function is passed as a parameter.
Syntax:
public <X extends Throwable> double
orElseThrow(Supplier<X> exceptionSupplier)
throws X extends Throwable
Parameters: This method accepts one parameter exceptionSupplier which is the supplying function that produces an exception to be thrown.
Return value: This method returns the value, if present.
Exception: This method throw following Exceptions:
- X – if no value is present.
- NullPointerException – if no value is present and the exception supplying function is null
- X extends Throwable
Below programs illustrate orElseThrow(Supplier) method:
Program 1:
// Java program to demonstrate// OptionalDouble.orElseThrow(Supplier) method  import java.util.OptionalDouble;  public class GFG {      public static void main(String[] args)    {          // create a OptionalDouble        OptionalDouble opDouble            = OptionalDouble.of(0.268924);          // apply orElseThrow(Supplier)        double value            = opDouble.orElseThrow(ArithmeticException::new);          System.out.println("value " + value);    }} |
Output:
Program 2:
// Java program to demonstrate// OptionalDouble.orElseThrow(Supplier) methodimport java.io.IOException;import java.util.OptionalDouble;  public class GFG {      public static void main(String[] args)    {          // create a OptionalDouble        OptionalDouble opDouble            = OptionalDouble.empty();          // apply orElseThrow(Supplier)        double value;          try {              value = opDouble.orElseThrow(IOException::new);        }        catch (IOException e) {              System.out.println("Exception " + e);        }    }} |
Output:
