#ExceptionHandler is Not working when automatic binding fails in REST API - spring-boot

Question

I have two REST API's GET POST
When any Exception is thrown inside the method, Exception handler is working fine.
But if i use malformed REST api uri then it only shows 400 Bad Request without going to Exception Handler.
Eg.
If I hit http://localhost:8080/mypojoInteger/abc, it fails to parse string into Integer and hence I am expecting it to go to ExceptionHandler.
It does not go to Exception Handler, Instead I only see 400 Bad Request.
It works fine and goes to Exception Handler when any Exception is thrown inside the GET/POST method.
For eg: It works fine and goes to Exception Handler if I use 123 in path variable
http://localhost:8085/mypojoInteger/123
And change getData method to
#GetMapping("/mypojoInteger/{sentNumber}")
public void getData(#PathVariable("sentNumber") Integer sentNumber) {
throw new NumberFormatException("Exception");
}
NOTE: Same issue is with POST request also.
GET:
#GetMapping("/mypojoInteger/{sentNumber}")
public void getData(#PathVariable("sentNumber") Integer sentNumber) {
//some code
}
POST:
public void postData(#RequestBody MyPojo myPojo) {
//some code
}
Controller Advice class:
#ControllerAdvice
public class CustomGlobalExceptionHandler extends ResponseEntityExceptionHandler {
#ExceptionHandler(NumberFormatException.class)
protected ResponseEntity<Object> handleEntityNotFound(
NumberFormatException ex) {
// some logic
}
}
How can I handle Exception when it fails to bind String to Integer in REST API uri itself??
EDIT: My Requirement is I should handle the overflow value of integer i.e, If a pass more than maximum value of Integer it must handle it rather than throwing NumberFormatException Stack Trace.
Eg: When i pass over flow value
POJO:
public class MyPojo extends Exception {
private String name;
private Integer myInt;
//getters/setter
}
{
"name":"name",
"myInt":12378977977987879
}
Without #ControllerAdvice it just shows the NumberFormatException StackTrace.
With #ControllerAdvice it just shows 400 bad request with no Response Entity.
I do not want this default stacktrace/400 bad request in case of this scenario
but I want to show my custom message.

Answer 1

The reason that i see is that, because since your request itself is malformed-> the method body never gets executed - hence the exception never occurs because it is only meant to handle the error within the method . It is probably a better design choice for you to form a proper request body rather than allowing it to execute any method so you know the problem before hand.

Answer 2

The issue is because Integer object is not sent as a valid request parameter, example of request: 5 if you send String an exception will be thrown directly. If you want to check if it is a String or Integer you might change your code by following this way:
#GetMapping("/mypojoInteger/{sentNumber}")
public void getData(#PathVariable("sentNumber") Object sentNumber) {
if (!(data instanceof Integer)) {
throw new NumberFormatException("Exception");
}
}
This should work on your example.

Answer 3

Solution:
I found out that I need to handle Bad Request.
So, I have override
#Override
protected ResponseEntity<Object> handleHttpMessageNotReadable(HttpMessageNotReadableException ex, HttpHeaders headers, HttpStatus status, WebRequest request) {
//Handle Bad Request
}