【springmvc】域对象共享数据

朱雀 2024-03-26 18:07 59阅读 0赞

## 域对象共享数据 ##

#### 1、使用ServletAPI向request域对象共享数据 ####

@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（推荐） ####

@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 mav = new ModelAndView();
        //向请求域共享数据
        mav.addObject("testScope", "hello,ModelAndView");
        //设置视图，实现页面跳转
        mav.setViewName("success");
        return mav;
    }

#### 3、使用Model向request域对象共享数据 ####

@RequestMapping("/testModel")
    public String testModel(Model model){
        
        model.addAttribute("testScope", "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("testScope", "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 ####

查看实际运行时类型 `map.getClass().getName()`

![image.png][]

Model、ModelMap、Map类型的参数其实本质上都是 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 {
 }

![image.png][image.png 1]

#### 7、向session域共享数据 ####

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

#### 8、向application域共享数据 ####

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

[image.png]: https://image.dandelioncloud.cn/pgy_files/images/2024/03/26/8760773d06614a749c90499a2775ef32.png
[image.png 1]: https://image.dandelioncloud.cn/pgy_files/images/2024/03/26/c1290d1d654e42cfa6de20245dfa9dd5.png