1.通过@RequestParam 坏处：参数变成url地址的一部分，如果没有值，则报错

如果是必不可少的参数，建议前面加@ RequestParam 

解决办法是，设置required为false

@RequestParam(value="age",required=false,defaultValue="0")

参数：

value:表示传递的属性名

required:表示是否为必须的

defaultValue:表示设置默认值---当传递的参数无法自动转型时

@Controller public class welcome {@RequestMapping({"welcome"})//@RequestParam("name") String name 意思是：拦截器拦截名为name的属性然后把值赋给String namepublic String welcomeTesr(@RequestParam("name") String name){System.out.println("wenlcome"+name);    return "/welcome";}}

2.通过直接配置参数 坏处：没传参数时候，值为null

@Controller public class welcome {@RequestMapping({"welcome"})public String welcomeTesr(String name){System.out.println("wenlcome"+name);return "/welcome";}}

3.如果是动态参数，使用@pathvariable 接收

@RequestMapping(value="/{username}",method=RequestMethod.GET) public String show (@PathVariable(value="username") String username,Model model){System.out.println(username);/*model.addAttribute(users.get(username));*/return "/users/show"; }

请求头包含了若干个属性，服务器可据此获取客户端的信息，通过@RequestHeader即可将求头中的属性值绑定到处理方法的参数中

@RequestMapping(value="/handler")public String handler(@RequestHeader("Accept-Encoding") String encoding){System.out.println(endoding);}

@CookieValue可以让方法绑定某个cookie值

@RequestMapping("/testCookieValue")public String testCookieValue(@cookieValue("JSESSIONID") String sessionId){System.out.println("testCookieValue:sessionId:"+sessionId);}

如：user.getName(),user.getId()

    
     username:
     passwrod:
     
     
    

@Controller@RequestMapping(value = "/sh")public class SpringHandler {@RequestMapping(value="testPOJO",method=RequestMethod.POST)public String testPOJO(User user){System.out.println(user);return null;}}

public class User {private String username;private String password;}

writer，调用的是response的返回getWriter()的方法

@RequestMapping(value="testServletApi")public String testServletApi(HttpServletRequest reqeust,HttpServletResponse response){System.out.println(reqeust+":"+response);return HELLO;}