Is There a Standard Java Exception Class for 'Object Not Found'?

What is the standard Java exception class to indicate that an object was not found?

// Example code to find a User by name
User findUserByName(Collection<User> users, String name) throws ObjectNotFoundException {
    for(User user : users) {
        if(user.getName().equals(name)) {
            return user;
        }
    }
    throw new ObjectNotFoundException();
}

In Java, there isn't a specific built-in exception class dedicated to indicating 'object not found' situations. However, several existing exceptions can serve a similar purpose, depending on the context of your application.

// Example using NoSuchElementException
User findUserByName(Collection<User> users, String name) {
    for(User user : users) {
        if(user.getName().equals(name)) {
            return user;
        }
    }
    throw new NoSuchElementException("User not found with name: " + name);
}

Causes

• The object does not exist in the provided collection.
• The identifier used to search for the object was incorrect or not found.

Solutions

• Use an existing Java exception like NoSuchElementException or IllegalArgumentException, which can convey similar meanings.
• If specific functionality is needed, it's advisable to implement a custom exception class for better readability and maintainability.

Mistake: Creating a custom exception class without evaluating existing options.

Solution: Check built-in exceptions like NoSuchElementException or others suitable for your context.

Mistake: Not providing informative messages in custom exceptions.

Solution: Always include detailed messages for better debugging and logging.