Reproducing the Error

Domain Model

java import lombok.Data; import java.util.Date;

@Data public class UserProfile { private String username; private String location; private Date createdAt; }

Endpoint Definition

java @PostMapping("/dates/submit") @ResponseBody public String processDate(UserProfile profile) { return profile.getCreatedAt().toString(); }

Scenario 1: Query Parameter Submission

When the client transmits the date as a URL query string (e.g., ?createdAt=2024-02-09 22:22:33), the server throws a conversion exception.

text ConversionFailedException: Failed to convert from type [java.lang.String] to type [java.util.Date] for value '2024-02-09 22:22:33'; nested exception is java.lang.IllegalArgumentException

Scenario 2: Multipart Form Data Submission

Submitting the value via form-data (e.g., createdAt=2024-02-07) results in the exact same conversion failure.

text ConversionFailedException: Failed to convert from type [java.lang.String] to type [java.util.Date] to value '2024-02-07'; nested exception is java.lang.IllegalArgumentException

Scenario 3: JSON Payload Submission

To accept JSON, the @RequestBody annotation must be added to the controller method:

java @PostMapping("/dates/submit") @ResponseBody public String processDate(@RequestBody UserProfile profile) { return profile.getCreatedAt().toString(); }

Using a simple date pattern (yyyy-MM-dd) like "2024-06-08" in the JSON body deserializes successfully. However, sending a timestamp with time components (yyyy-MM-dd HH:mm:ss), such as "2024-06-08 22:11:33", triggers a Jackson parsing error.

text HttpMessageNotReadableException: JSON parse error: Cannot deserialize value of type java.util.Date from String "2024-06-08 22:11:33": not a valid representation (error: Failed to parse Date value '2024-06-08 22:11:33': Cannot parse date "2024-06-08 22:11:33": while it seems to fit format 'yyyy-MM-dd'T'HH:mm:ss.SSSX', parsing fails (leniency? null))