Issue
I have custom converter:
@Component
public class RoleConverter implements Converter<String, Role> {
@Autowired private Roles roles;
@Override
public Role convert(String id) {
return roles.findById(Long.parseLong(id));
}
}
But @Autowired is setting null value. Causing Nullpointerexception.
This is Roles class:
@Repository
@Transactional
public class Roles extends Domain<Role>{
public Roles() {
super(Role.class);
}
}
I'm using Java Configuration. Converter is registered:
@Configuration
@EnableWebMvc
//other annotations...
public class WebappConfig extends WebMvcConfigurerAdapter {
//....
@Override
public void addFormatters(FormatterRegistry registry) {
registry.addConverter(new RoleConverter());
super.addFormatters(registry);
}
/....
}
When I @Autowired Roles in controller its works.
Why @Autowired is setting null in Converter?
Solution
It is because here you are creating a new object of RoleConverter. Instead you should autowire the RoleConverter
Instead of
registry.addConverter(new RoleConverter());
Use
@Autowired
RoleConverter roleConverter;
@Override
public void addFormatters(FormatterRegistry registry)
{
registry.addConverter(roleConverter);
}
Answered By - Bhushan Bhangale
Answer Checked By - Cary Denson (JavaFixing Admin)
