Spring MVC 的请求参数获取

1. 通过@PathVariabl注解获取路径中传递参数
   JAVA
   1      @RequestMapping(value  =   " /{id}/{str} " )
   2       public  ModelAndView helloWorld(@PathVariable String id,
   3              @PathVariable String str) {
   4          System.out.println(id);
   5          System.out.println(str);
   6           return   new  ModelAndView( " /helloWorld " );
   7      }
2. 用@ModelAttribute注解获取POST请求的FORM表单数据
   JSP
   1  < form method = " post "  action = " hao.do " >
   2  a:  < input id = " a "  type = " text "    name = " a " />
   3  b:  < input id = " b "  type = " text "    name = " b " />
   4  < input type = " submit "  value = " Submit "   />
   5  </ form >
   
   JAVA pojo
   1  public   class  Pojo{
   2       private  String a;
   3       private   int  b;
   4     
   5 
   
   JAVA controller
   1  @RequestMapping(method  =  RequestMethod.POST)
   2       public  String processSubmit(@ModelAttribute( " pojo " ) Pojo pojo) { 
   3          
   4           return   " helloWorld " ;
   5      }
3. 直接用HttpServletRequest获取
   JAVA
   1      @RequestMapping(method  =  RequestMethod.GET)
   2       public  String get(HttpServletRequest request, HttpServletResponse response) {
   4          System.out.println(request.getParameter( " a " ));
   5           return   " helloWorld " ;
   6      }
4. 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)
   JAVA
   1      @RequestMapping(value  =   " /requestParam " , method  =  RequestMethod.GET)
   2       public  String setupForm(@RequestParam( " a " ) String a, ModelMap model) {
   3          System.out.println(a);
   4          return "helloWorld";}