SpringMVC——域对象共享数据

域对象共享数据

1、使用 ServletAPI 向 request 域对象共享数据

<a th:href="@{/testRequestByServletAPI}">通过servletAPI向request域对象共享数据a><br/>

@RequestMapping("/testRequestByServletAPI")
//使用servletAPI向request域对象共享数据
public String testRequestByServletAPI(HttpServletRequest request){
    request.setAttribute("testRequestScope", "hello, servletAPI");
    return "success";
}

<p th:text="${testRequestScope}">p>

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2、使用 ModelAndView 向request 域对象共享数据：推荐使用

<a th:href="@{/testModelAndView}">通过ModelAndView向request域对象共享数据a><br/>

@RequestMapping("/testModelAndView")
public ModelAndView testModelAndView(){
    ModelAndView mav = new ModelAndView();
    //处理模型数据，即向请求域request共享数据
    mav.addObject("testRequestScope", "hello, ModelAndView");
    //设置视图名称
    mav.setViewName("success");
    return mav;
}

注意：

• 返回值必须是 ModelAndView；

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3、使用 Model 向 request 域对象共享数据

<a th:href="@{/testModel}">通过Model向request域对象共享数据a><br/>

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

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4、使用 map 向 request 域对象共享数据

<a th:href="@{/testMap}">通过Map向request域对象共享数据a><br/>

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

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5、使用 ModelMap 向 request 域对象共享数据

<a th:href="@{/testModelMap}">通过ModelMap向request域对象共享数据a><br/>

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

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6、Model、ModelMap、Map 的关系

Model、ModelMap、Map 类型的参数其实本质上都是 BindingAwareModelMap 类型的。

@RequestMapping("/testModel")
public String testModel(Model model){
    model.addAttribute("testRequestScope", "hello, Model");
    System.out.println(model.getClass().getName());
    //org.springframework.validation.support.BindingAwareModelMap
    return "success";
}

@RequestMapping("/testMap")
public String testMap(Map<String, Object> map){
    map.put("testRequestScope", "hello, Map");
    System.out.println(map.getClass().getName());
    //org.springframework.validation.support.BindingAwareModelMap
    return "success";
}

@RequestMapping("/testModelMap")
public String testModelMap(ModelMap modelMap){
    modelMap.addAttribute("testRequestScope", "hello, ModelMap");
    System.out.println(modelMap.getClass().getName());
    //org.springframework.validation.support.BindingAwareModelMap
    return "success";
}

public interface Model{}

public class ModelMap extends LinkedHashMap {}

public class ExtendedModelMap extends ModelMap implements Model {}

public class BindingAwareModelMap extends ExtendedModelMap {}

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7、向 session 域共享数据

<a th:href="@{/testSession}">通过servletAPI向session域对象共享数据a><br/>

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

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

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8、向 application 域共享数据

<a th:href="@{/testApplication}">通过servletAPI向application域对象共享数据a><br/>

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

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