In Spring 3 it is not possible to set @Autowired in either static fields or methods, so since I want to declare an utility class such as:
public class SchoolYearServiceUtil {
private static SchoolYearService schoolYearService;
public static SchoolYear getSchoolYear(Long id) {
return schoolYearService.get(id);
}
}
to avoid having to inject the schoolYearService everywhere (jsp, command class...) in which I need it. In this case, I don't need an interface to be implemented by SchoolYearServiceUtil.
I don't want to have to initialize the object through code but getting the same instance as the Spring's one.
Which would be the best option to implement the getSchoolYear as a static method?
Thanks.
Would this be conceptually wrong?:
@Component
public class SchoolYearServiceUtil {
private static SchoolYearService schoolYearService;
@Autowired(required = true)
private SchoolYearServiceUtil(@Qualifier("schoolYearServiceImpl") SchoolYearService schoolYearService) {
SchoolYearServiceUtil.schoolYearService = schoolYearService;
}
public static SchoolYearService getSchoolYearService() {
r开发者_JAVA技巧eturn schoolYearService;
}
public static SchoolYear getSchoolYear(Long id) {
return getSchoolYearService().get(id);
}
}
I would have to make sure that only Spring calls once the constructor and the constructor is called nowhere else, that's why I declared the constructor as private.
I fully support skaffman's comment. You don't need static
fields with DI. You just define a bean of scope singleton (default).
There is a way to obtain a bean statically, but you should be aware that it is not to be used in regular situations. (there are some valid applications). It is to use the WebApplicationContextUtils.getRequiredWebApplicationContext(servletContext)
You notice that you need to pass a ServletContext
argument.
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