如何设置Controller范围的全局变量

Question

目前我@ModelAttribute用来设置全局变量(例如页脚的推文)@Controller:

public @Controller class MainController {
    public @ModelAttribute void global(ModelMap map) {
        map.addAttribute("tweets", /*...*/null);
    }
}

但是在创建另一个控制器以保持干净和分离时,它们在逻辑上已经消失了:

public @Controller class GalleryController {
    // ...
}

设置全局变量控制器范围的最佳做法是什么？

Answer 1

如果你想把一些数据放到每个页面,很容易使用拦截器:

public class PagePopulationInterceptor extends HandlerInterceptorAdapter {

    @Autowired
    private UserService userService;

    @Override
    public void postHandle(HttpServletRequest request, HttpServletResponse response, Object handler, ModelAndView modelAndView) throws Exception {
        if(modelAndView != null) {
            User user = userService.findOne(request);
            modelAndView.addObject("myUserProfile", user);
        }
    }

}

为了使这项工作也在webmvc-config.xml中声明拦截器(webapp的spring配置):

<mvc:interceptors>
    <mvc:interceptor>
        <mvc:mapping path="/**"/>
        <bean class="com.yourcompany.yourapp.util.PagePopulationInterceptor" />
    </mvc:interceptor>
    <!-- other interceptors (locale, theme and so on) -->
</mvc:interceptors>