@RequestParam如何处理错误框架的URL

Question

我正在进行如下方法测试，并进行RESTful webservice调用以获取数据，

@RequestMapping(value ="/select", method = RequestMethod.GET)
@ResponseBody
public String test(
@RequestParam(value="begin", defaultValue="0",required=false) final String begin
)
{
//Some java code
}

**RESTful Webservice Call:**
http://localhost:8081/a/b/c/select?begin=1
Returning the data properly

http://localhost:8081/a/b/c/select?begin:1
Here in the url = has been replaced with : for negative testing.
Here Spring ignores the given value 1 and picks the default value 0 and returns the data accordingly without errors

Question:
But I want to capture the actual URL field with value which is begin:1, do some validation and display error message that the url is incorrect.

I understood that begin:1 is not considered as part of url by spring and hence picks the default value. Wondering is there a way in Spring to capture the wrongly framed url's.
Any pointers would be helpful. Many Thanks!