springmvc请求接收参数的几种方法

一、通过@PathVariable获取路径中的参数

  @RequestMapping(value="user/{id}/{name}",method=RequestMethod.GET)
     public String printMessage1(@PathVariable String id,@PathVariable String name, ModelMap model) {

         System.out.println(id);
         System.out.println(name);
         model.addAttribute("message", "获取URL的参数");
         return "users";
  }

例如，访问user/123/hello路径时，执行以上方法，其中，参数id=123，name=hello

二、@ModelAttribute获取POST请求的FORM表单数据

页面表单记得加上name属性

     <form method="post" action="hao.do">
      a: <input id="a" type="text" name="a"/>
      b: <input id="b" type="text" name="b"/>
      <input type="submit" value="Submit" />
     </form>  

用来接收的Java类：

 public class Pojo{
      private String a;
      private int b;

     //setter、getter
 }

Java的controller：

 @RequestMapping(method = RequestMethod.POST)
 public String processSubmit(@ModelAttribute("pojo") Pojo pojo) { 

     System.out.println(pojo.getA());
     System.out.println(pojo.getB());
     return "helloWorld";
 }

三、直接用HttpServletRequest获取

@RequestMapping(method = RequestMethod.GET)
public String get(HttpServletRequest request, HttpServletResponse response) {
    System.out.println(request.getParameter("a"));
    return "helloWorld";
}

四、用注解@RequestParam绑定请求参数

用注解@RequestParam绑定请求参数a到变量a
当请求参数a不存在时会有异常发生,可以通过设置属性required=false解决,
例如: @RequestParam(value="a", required=false)

@RequestMapping(value = "/requestParam", method = RequestMethod.GET)
public String setupForm(@RequestParam("a") String a, ModelMap model) {
   System.out.println(a);
   return "helloWorld";
}