If I couldn't find a user in my db with given id. I want to return an exception instead of null Dto, how can I do this?
public UserDto updateUser(Long id, UserDto userDto) {
UserDto userDtoNew = null;
if (userRepository.findById(id).isPresent()) {
User existingUser = userRepository.findById(id).get();
existingUser.setPassword(userDto.getPassword());
existingUser.setUserName(userDto.getUserName());
userDtoNew = userMapper.toDto(existingUser);
return userDtoNew;
}
return userDtoNew;
}
This is a terrible way to use a an Optional. Please learn how to properly use it.
return userRepository.findById(id)
.map(it -> {
it.setPassword(userDto.getPassword());
it.setUserName(userDto.getUserName());
}).map(userMapper::toDto)
.orElseThrow(() -> new IllegalArgumentException("No user found for " + id));
Something along those lines is how to properly use an Optional and to throw an exception if nothing is found.
Ideally the thing called inside the map function/method is just a oneliner. So instead of having the code block with {} you might want to move that to a method to make it more readable.
private User update(User user, UserDto userDto) {
user.setPassword(userDto.getPassword());
user.setUserName(userDto.getUserName());
return user;
}
return userRepository.findById(id)
.map(it -> update(it, userDto))
.map(userMapper::toDto)
.orElseThrow(() -> new IllegalArgumentException("No user found for " + id));