使用SpringMVC开发，Controller层如何获取Interceptor层放入的参数

在Interceptor中，可以通过HandlerInterceptor的preHandle方法将参数放入HttpServletRequest中的attribute中，然后在Controller中通过HttpServletRequest的getAttribute方法获取：

Interceptor中：

public class MyInterceptor implements HandlerInterceptor {
    @Override
    public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {
        request.setAttribute("myParam", "ParamValue");
        return true;
    }
}

Controller中：

@Controller
public class MyController {
    @RequestMapping("/test")
    public String test(HttpServletRequest request) {
        String myParam = (String) request.getAttribute("myParam");
        System.out.println(myParam); // 输出 "ParamValue"
        return "test";
    }
}