五、域对象共享数据

1、使用ServletAPI向request域对象共享数据

index.html

<a th:href="@{/testServletAPI}">testServletAPI</a>

success.html

<p th:text="${testScope}"></p>

    @RequestMapping("/testServletAPI")
    public String testServletAPI(HttpServletRequest request){
    
        request.setAttribute("testScope", "Hello,ServletAPI");
        return "success";
    }

2、使用ModelAndView向request域对象共享数据

   @RequestMapping("/testModelAndView")
    public ModelAndView testModelAndView(){
    
        /** * ModelAndView有Model和View的功能 * Model主要用于向请求域共享数据 * View主要用于设置视图，实现页面跳转 */
        ModelAndView mv = new ModelAndView();
        //向请求域共享数据
        mv.addObject("testModelAndView", "Hello,ModelAndView");
        //设置视图，实现页面跳转
        mv.setViewName("success");
        return mv;
    }

3、使用Model向request域对象共享数据

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

4、使用map向request域对象共享数据

    @RequestMapping("/testMap")
    public String testMap(Map<String, Object> map){
    
        map.put("testMap", "Hello,Map");
        return "success";
    }

5、使用ModelMap向request域对象共享数据

    @RequestMapping("/testModelMap")
    public String testModelMap(ModelMap modelMap){
    
        modelMap.addAttribute("testScope", "Hello,ModelMap");
        return "success";
    }

6、Model、ModelMap、Map的关系

Model、ModelMap、Map类型的参数本质上都是 BindingAwareModelMap 类型的

public interface Model{
    }
public class ModelMap extends LinkedHashMap<String, Object> {
    }
public class ExtendedModelMap extends ModelMap implements Model {
    }
public class BindingAwareModelMap extends ExtendedModelMap {
    }

7、向session域共享数据

<p th:text="${session.testScope}"></p>

    @RequestMapping("/testModelMap")
    public String testModelMap(ModelMap modelMap){
    
        modelMap.addAttribute("testScope", "Hello,ModelMap");
        return "success";
    }

    @RequestMapping("/testSession")
    public String testSession(HttpSession session){
    
        session.setAttribute("testScope", "Hello,Session");
        return "success";
    }

8、向application域共享数据

<p th:text="${application.testApplicationScope}"></p>

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