如何在HTTP异常处理期间从请求中获取POST正文？

Question

I have 2 microservices. 1 of them sends a request to 2, 2 microservice throws an exception and adds new addition field errors to response with useful data:

    public static class ErrorResponse  {
        private Integer status;
        private String transactionId;
        private String sessionId;
        private String message;
        private List<FieldError> errors;
    //....setters/getters
    }

{
    "status": 400,
    "message": "Validation failed for object='x'. Error count: 1",
    "sessionId": "",
    "transactionId": "xxx",
    "errors": [
        {
            "codes": [
                ""
            ],
            "arguments": null,
            "defaultMessage": null,
            "objectName": "",
            "field": "",
            "rejectedValue": 0,
            "bindingFailure": false,
            "code": "invalid value"
        }
    ]
}

in 1 microservice I have a global exception handler which sends it on client, but the problem is that I can't get the filed errors from HttpServletRequest . getReader() method throws another exception. And as result client gets

{
    "status": 400,
    "message": "Validation failed for object='x'. Error count: 1",
    "sessionId": "",
    "transactionId": "xxx",
    "errors": null
}

Answer 1

You can't call getReader a second time. This link explains why: resetting a HttpRequest after calling request.getReader() . You can pass this information through a thread local if its something globally used through the application. You would need to make sure to reset the thread local appropriately. You could also catch the previous exception, wrap it in a custom exception class, and put this information inside of your custom exception. Then you can throw your custom exception that has the information you need.

Answer 2

the solution is to implement ErrorDecoder interface and override

@Override
Exception decode(String methodKey, Response response) {
    // response has getBody() method to get all data from a request 
}