What is the cause of java.util.NoSuchElementException: No value present

Share post:

The java.util.NoSuchElementException: No value present error is a runtime exception that occurs when an optional value is not present in a Java program.

I am accessing this code and getting the java.util.NoSuchElementException exception.

return productRepository.findById(i).get();

The java.util.NoSuchElementException: No value present error is a runtime exception that occurs when an optional value is not present in a Java program.

In Java, the Optional class is used to represent values that may be absent. When you call the get() method on an Optional an object that has no value, this error is thrown. This can happen if you try to access an empty Optional or if you try to retrieve a value from an Optional that was not set.

Here's an example of how this error can occur:

Optional<String> optionalValue = Optional.empty();
String value = optionalValue.get(); // throws NoSuchElementException

 

To avoid this error, you should always check if an Optional value is present before calling the get() method. You can do this using the isPresent() method or by using the orElse() method to provide a default value if the Optional value is not present.

Here's an example of how to avoid the error by using the isPresent() method:

Optional<String> optionalValue = Optional.empty();
if (optionalValue.isPresent()) {
    String value = optionalValue.get();
    // do something with the value
} else {
    // handle the case where the value is not present
}

 

And here's an example of how to avoid the error by using the orElse() method:

Optional<String> optionalValue = Optional.empty();
String value = optionalValue.orElse("default value");
// use the value, which will be "default value" in this case

Conclusion

Optional is a class in Java that was introduced in Java 8. It is a container object that may or may not contain a non-null value. In other words, it's a way of representing the possibility that a value may be absent.

The purpose of Optional is to provide a clearer and safer way of handling null values.  

Smashplus

Insights

Share post: