java - Spring-MVC @ModelAttribute和@Autowired

我正在尝试使用方法上的@ModelAttribute Annontation初始化对象。当调用URL“ / p / PPP / scope”时，会发生奇怪的事情。调用@ModelAttribute方法时，似乎不会实例化ProjectService，但调用show（）方法时，ProjectService在那里。有谁知道这有什么问题吗？

以下是日志语句：

12:32:19 [DEBUG] ScopeController - getProject() - loading project for 'PPP'
12:32:19 [DEBUG] ScopeController - getProject() - projectService initialized? null
12:32:21 [DEBUG] ScopeController - show() - projectService initialized? ...project.ProjectService@20f2442e

以及来源：

@Controller
@RequestMapping("/p/{abbr}/scope")
@SessionAttributes("project")
public class ScopeController {

    public static final String SHOW_PROJECT_PAGE = "/projects/scope/show";

    private static final Logger log = LoggerFactory.getLogger(ScopeController.class);

    @Autowired
    private ProjectService projectService;

    @ModelAttribute("project")
    private Project getProject(@PathVariable(value = "abbr") String abbr) {
        log.debug("getProject() - loading project for '{}'", abbr);
        log.debug("getProject() - projectService initialized? {}", projectService);
        // should call this method:
        // return projectService.find(abbr);
        return new Project();
    }

    @RequestMapping(method = RequestMethod.GET)
    @Transactional
    public String show() throws BindException {
        log.debug("show() - projectService initialized? {}", projectService);
        return SHOW_PROJECT_PAGE;
    }
}

最佳答案

具有ModelAttibute批注的所有方法必须是公共的。

因此，当方法getProject为公共方法时，它将可以正常工作：

 @ModelAttribute("project")
 public Project getProject( ...