SpringMVC 域对象共享数据的实现示例

目录

• 使用ModelAndView向request域对象共享数据
• 使用Model向request域对象共享数据
• 使用map向request域对象共享数据
• 使用ModelMap向request域对象共享数据
• Model、ModelMap、Map的关系
• 向session域共享数据
• 向application域共享数据

<a th:href="@{/testModelAndView}" rel="external nofollow" >使用ModelAndView</a>

 /**
     * 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
     */
    @RequestMapping("/testModelAndView")
    public ModelAndView success(){
        ModelAndView modelAndView = new ModelAndView();
        modelAndView.addObject("username","gonghr");   //向请求域共享数据
        modelAndView.setViewName("success");  //设置视图名称，实现页面跳转
        return modelAndView;  //返回
    }

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

<a th:href="@{/testModel}" rel="external nofollow" >使用Model</a> <br>

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

sucess
<p th:text="${company}"></p> <br>

<a th:href="@{/testMap}" rel="external nofollow" >使用Map</a> <br>

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

sucess
<p th:text="${age}"></p> <br>

<a th:href="@{/testModelMap}" rel="external nofollow" >使用ModelMap</a> <br>

 @RequestMapping("/testModelMap")
    public String testModelMap(ModelMap modelMap){
        modelMap.addAttribute("major","software engineering");
        return "success";
    }

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

class of ModelAndView:  class org.springframework.web.servlet.ModelAndView
class of Model:         class org.springframework.validation.support.BindingAwareModelMap
class of Map:           class org.springframework.validation.support.BindingAwareModelMap
class of ModelMap:      class org.springframework.validation.support.BindingAwareModelMap

public class ModelAndView {

    @Nullable
    private ModelMap model;
   
    public ModelAndView() {
    }
	
    public ModelMap getModelMap() {
        if (this.model == null) {
            this.model = new ModelMap();
        }
        return this.model;
    }
    public ModelAndView addObject(String attributeName, @Nullable Object attributeValue) {
        this.getModelMap().addAttribute(attributeName, attributeValue);
        return this;
    }

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

<a th:href="@{/testSession}" rel="external nofollow" >使用Session</a> <br>

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

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

<a th:href="@{/testApplication}" rel="external nofollow" >使用Application</a> <br>

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

    }

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