Java – using spring MVC and accepting post requests with wrong JSON will result in returning the default 400 error code server page

I'm using the rest API Receiving a post message with bad JSON (such as {sdfasdf}) will cause spring to return a 400 error request to the wrong default server page I don't want to return a page, I want to return a custom JSON error object

I can do this when I throw an exception using @ exceptionhandler So if it is a blank request or a blank JSON object (such as {}), it will throw a NullPointerException. I can grab it with my exceptionhandler and do whatever I like

The problem is that spring doesn't throw exceptions when it's just invalid syntax, at least I can't see it It just returns the default error page from the server, whether tomcat, GlassFish, etc

So my question is how can I "intercept" spring and cause it to use my exception handler or otherwise prevent the error page from displaying instead of returning a JSON error object?

This is my code:

@RequestMapping(value = "/trackingNumbers",method = RequestMethod.POST,consumes = "application/json")
@ResponseBody
public ResponseEntity<String> setTrackingNumber(@RequestBody TrackingNumber trackingNumber) {

    HttpStatus status = null;
    ResponseStatus responseStatus = null;
    String result = null;
    ObjectMapper mapper = new ObjectMapper();

    trackingNumbeRSService.setTrackingNumber(trackingNumber);
    status = HttpStatus.CREATED;
    result = trackingNumber.getCompany();


    ResponseEntity<String> response = new ResponseEntity<String>(result,status);

    return response;    
}

@ExceptionHandler({NullPointerException.class,EOFException.class})
@ResponseBody
public ResponseEntity<String> resolveException()
{
    HttpStatus status = null;
    ResponseStatus responseStatus = null;
    String result = null;
    ObjectMapper mapper = new ObjectMapper();

    responseStatus = new ResponseStatus("400","That is not a valid form for a TrackingNumber object " + 
            "({\"company\":\"EXAMPLE\",\"pro_bill_id\":\"EXAMPLE123\",\"tracking_num\":\"EXAMPLE123\"})");
    status = HttpStatus.BAD_REQUEST;

    try {
        result = mapper.writeValueAsString(responseStatus);
    } catch (IOException e1) {
        e1.printStackTrace();
    }

    ResponseEntity<String> response = new ResponseEntity<String>(result,status);

    return response;
}

Solution

This is a problem with spring spr-7439 - the JSON (Jackson) @ requestbody grouping raises an embarrassing exception - in spring 3.1m2, it has been fixed that spring throws an org. Org in a missing or invalid case springframework. http. converter. Httpmessagenotreadableexception message body

In your code, because it is abstract, you can't create a responsestatus, but I use spring 3.2 0.release in jetty 9.0 3. Use the local test method running on v20130506 to catch this exception

@ExceptionHandler({org.springframework.http.converter.HttpMessageNotReadableException.class})
@ResponseStatus(HttpStatus.BAD_REQUEST)
@ResponseBody
public String resolveException() {
    return "error";
}

I received a 400 status "error" string response

The defects have been discussed at this spring forum

Note: I started using jetty 9.0 0.m4 for testing, but there are other internal problems that prevent the completion of @ exceptionhandler, so according to your container (jetty, Tomcat, other) version, you may need to get a better version, any version of spring you use