• 通过原生Servlet方法
• 通过ModelAndView
• 通过Model
• 通过Map
• 通过ModelMap

index.html


This is index.html
使用RequestAPI向request域中传值

使用modelAndView向request域中传值

使用model向request域中传值

使用map向request域中传值

使用modelMap向request域中传值



success.html


success

@Controller
public class ScopeController {
    @RequestMapping("/testRequestAPI")
    public String testRequestAPI(HttpServletRequest request){
        request.setAttribute("requestScope","hello,RequestAPI");
        return "success";
    }

    @RequestMapping("/modelAndView")
    public ModelAndView testModelAndView(){
        ModelAndView mav = new ModelAndView();
        mav.setViewName("success");
        mav.addObject("requestScope","hello,session");
        return mav;
    }

    @RequestMapping("/model")
    public String testModel(Model model){
        model.addAttribute("requestScope","hello,model");
        return "success";
    }

    @RequestMapping("/map")
    public String testMap(Map map){
        map.put("requestScope","hello,map");
        return "success";
    }

    @RequestMapping("/modelMap")
    public String testMap(ModelMap modelMap){
        modelMap.addAttribute("requestScope","hello,modelMap");
        return "success";
    }
}

以上五种方式，都可以讲数据传输到request域中

model，map，modelMap的关系

我们在三个方法中分别加入一段输出全路径，结果都为org.springframework.validation.support.BindingAwareModelMap，可以得知三者的参数其实本质上都是 BindingAwareModelMap 类型的

    @RequestMapping("/model")
    public String testModel(Model model){
        model.addAttribute("requestScope","hello,model");
        System.out.println(model.getClass().getName());
        return "success";
    }

    @RequestMapping("/map")
    public String testMap(Map map){
        map.put("requestScope","hello,map");
        System.out.println(map.getClass().getName());
        return "success";
    }

    @RequestMapping("/modelMap")
    public String testMap(ModelMap modelMap){
        modelMap.addAttribute("requestScope","hello,modelMap");
        System.out.println(modelMap.getClass().getName());
        return "success";
    }

我们来看一下BindingAwareModelMap的结构

public interface Model{}
public interface Map{}
public class ModelMap extends linkedHashMap {}
public class ExtendedModelMap extends ModelMap implements Model {}
public class BindingAwareModelMap extends ExtendedModelMap {}

五个方法中，不论用哪种方法实现向域中传输数据，最后都是封装成ModelAndView对象来传递

无论哪种方法，都会经过前端控制器，前端控制器中有一个doDispatch方法，里面都会将这些值封装成一个ModelAndView对象

SpringMVC提供了注解方法来设置Session域中的值，但不如原生request方法来的简单，而像application域中传值，只需要调用Session即可

    @RequestMapping("/session")
    public String testSession(HttpSession session){
        session.setAttribute("requestScope","hello,session");
        return "success";
    }

    @RequestMapping("/application")
    public String testApplication(HttpSession session){
        ServletContext application = session.getServletContext();
        application.setAttribute("requestScope","hello,application");
        return "success";
    }

success