錯誤描述：

@RequestMapping(value = "/index")
	public String index(@RequestParam(value = "action", required = false)
	String action, @RequestParam(value = "notIncludeTypeId", required = false)
	int notIncludeTypeId){
    // .... 省略程式碼
}

      當可選引數“notIncludeTypeId”為空時，系統出現如下錯誤： 

Optional int parameter 'notIncludeTypeId' is not present 
but cannot be translated into a null value due to being declared as a primitive type. 
Consider declaring it as object wrapper for the corresponding primitive type.
 

錯誤原因：

    當可選引數“notIncludeTypeId”不存在時，Spring預設將其賦值為null，但由於notIncludeTypeId已定於為基本型別int，所以賦值失敗！

解決方法：

    “Consider declaring it as object wrapper for the corresponding primitive type.”建議使用包裝型別代替基本型別，如使用“Integer”代替“int”