在Java控制器上，如何获取批注@RequestMapping（“ / getThisValueFromOtherClass”）的值？

Question

On Java MVC Controller how to get the value of annotation @RequestMapping("/getThisValueFromOtherClass")? I know we can extract this by using java reflections but is there any other way? Thank you.

@RequestMapping("/getThisString")
public class MyController{}

Answer 1

If the purpose is just to avoid changing the url at every place, I will suggest define a string constant in some class and instead of using hard coded string in request mapping use that constant every where. In future if u want tp\\o change the url, simple update the constant value at one place

final String constUrl = "/myurl";

@RequestMapping(value=constUrl)

you can make the constant static, if defining in another class

Answer 2

The value of the annotation can be read programmatically:

@RequestMapping("/endpoints")
public ResponseEntity<String> getPath() {
    String path = getClass().getAnnotation(RequestMapping.class).value()[0];
    return new ResponseEntity<String>(path, HttpStatus.OK);
}

Answer 3

To obtain the path, you should pass the Request ie HttpServletRequest as a parameter to your handler method.

@RequestMapping(value={"/getThisString"}, method=RequestMethod.GET)
public String handlerMethod (Model model, HttpServletRequest request) throws Exception {             
   String getThatString = request.getServletPath(); 
   ....
}

Reference:

• HttpServletRequest

Answer 4

In your case if an URI pattern “/getThisString” is requested, it will map to this MyController , and handle the request with method where @RequestMapping(method = RequestMethod.GET) is declared.

You can refer this tutorial @RequestMapping example

Hope it helps.