springMVC--(讲解3)数据处理

时间 2019-11-21

原文原文链接

#1.传入数据单个值(方式1)
没有使用视图解析器
controller代码以下html

@RequestMapping(value="/hello",method= RequestMethod.GET)
	public String hello(String name) throws IOException, ServletException{
		System.out.println(name);
		return "index.jsp";
	}

请求代码app

http://localhost:8080/ssm/hello?name=zhangsan

注意：请求的参数名(name)必须和接收参数(String name)对齐，不然接收不到。
#2.传入数据单个值(方式2)
使用@RequestParam接收参数。
请求代码同上
接收代码改成以下jsp

@RequestMapping(value="/hello",method= RequestMethod.GET)
	public String hello(@RequestParam("name")String userName) throws IOException, ServletException{
		System.out.println(userName);
		return "index.jsp";
	}

#3.传对象code

@RequestMapping(value="/hello",method= RequestMethod.GET)
	public String hello(User user) throws IOException, ServletException{
		System.out.println(user);
		return "index.jsp";
	}

User类以下htm

public class User implements Serializable{

	private static final long serialVersionUID = 1L;

	private Integer id;

        private String name;
}

传参以下对象

http://localhost:8080/ssm/hello?name=zhangsan&id=1001

#4.数据展现到前台(方式1：ModAndView)
使用视图解析器io

@RequestMapping(value="/hello",method= RequestMethod.GET)
	public ModelAndView hello(User user) throws IOException, ServletException{
		
		ModelAndView mav = new ModelAndView();
		mav.addObject("user", user);
		mav.setViewName("hello");
		return mav;
	}

请求数据class

http://localhost:8080/ssm/hello?name=zhangsan&id=1001

hello.jsp请求

<html>
<body>
<h2>Hello World!</h2>
userId:${user.id}<br>
userName:${user.name}
</body>
</html>

结果im

Hello World!
userId:1001
userName:zhangsan

#5.数据展现到前台(方式2：ModleMap)
不须要使用视图解析器

@RequestMapping(value="/hello",method= RequestMethod.GET)
	public String hello(User user,ModelMap modlMap) throws IOException, ServletException{
		modlMap.addAttribute("user", user);
		return "index.jsp";
	}

请求数据

http://localhost:8080/ssm/hello?name=zhangsan&id=1001

index.jsp

<html>
<body>
<h2>Hello World!</h2>
userId:---  ${user.id}<br>
userName:---  ${user.name}
</body>
</html>

结果

Hello World!
userId:--- 1001
userName:--- zhangsan

ModelAndView与ModelMap的区别 1.前者须要视图解析器，然后者不须要。 2.前者能够设值且指定跳转的页面，然后者只能设值。