ErrorEntity.java

// .... imports ommited for brevity
public class ErrorEntity  implements Serializable {

    int status; // contains the same HTTP Status code returned by the server
    String message; // message describing the error
    String developerMessage;  // extra information that might useful for developers
    
    public ErrorEntity(int status, Exception ex) {
        StringWriter errorStackTrace = new StringWriter();
        ex.printStackTrace(new PrintWriter(errorStackTrace));

        this.developerMessage = errorStackTrace.toString();
        this.status = status;
        this.message = ex.getMessage();
    }

    public ErrorEntity(String message) {
        this.status = Response.Status.BAD_REQUEST.getStatusCode();
        this.message = message;
        this.developerMessage = message;
    }
    
    // getters and setters ....
}