SpringMVC作用域传值的方式

朱雀 2022-05-06 04:00 202阅读 0赞

## 使用原生Servlet ##

在HandlerMethod参数中添加作用域对象

@RequestMapping("demo")
    	public String demo1(HttpServletRequest req, HttpSession sessionParam) {
    		req.setAttribute("req", "req的值");
    		HttpSession session = req.getSession();
    		session.setAttribute("session", "session的值");
    		sessionParam.setAttribute("sessionParam", "sessionParam的值");
    		ServletContext application = req.getServletContext();
    		application.setAttribute("application", "application的值");
    		return "index2";		
    	}

jsp

request	${requestScope.req } 
 session	${sessionScope.session } 
 sessionParam ${sessionScope.sessionParam } 
 application	${applicationScope.application }

结果

request	req的值
    session	session的值
    sessionParam	sessionParam的值
    application	application的值

当用demo2跳转同样跳转到index2时

@RequestMapping("demo2")
    	public String demo12() {		
    		return "index2";		
    	}

输出

request	
    session	session的值
    sessionParam	sessionParam的值
    application	application的值

可以看到request的值已经没有了

## Map ##

@RequestMapping("demo3")
 	public String demo3(Map<String,Object> map) {	
 		map.put("map", "map的值");
 		return "index2";		
 	}

jsp

map ${map }

输出

map map的值

## SpringMVC的Model接口 ##

@RequestMapping("demo4")
    	public String demo4(Model model) {	
    		model.addAttribute("model", "model的值");
    		return "index2";
    		
    	}

jsp

model ${model }

输出

model model的值

## ModelAndView ##

@RequestMapping("demo5")
    	public ModelAndView demo5() {	
    		ModelAndView mav = new ModelAndView("index2");
    		mav.addObject("mav","mav的值");
    		return mav;		
    	}

jsp

mav ${requestScope.mav }

输出

mav mav的值