Spring MVC 的请求参数获取的几种方法

通过@PathVariabl注解获取路径中传递参数

     @RequestMapping(value = "/{id}/{str}")
     public ModelAndView helloWorld(@PathVariable String id,
             @PathVariable String str) {
         System.out.println(id);
         System.out.println(str);
         return new ModelAndView("/helloWorld");
     } 

用@ModelAttribute注解获取POST请求的FORM表单数据

 <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> 

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

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

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";
     } 

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";
 
}