👀 Views: 57 💬 Answers: 1 📅 Created: 2025-06-06

spring-boot jackson localdatetime Java

I'm facing an issue where LocalDateTime fields in my Spring Boot application are sometimes serialized as null when returned in JSON responses. I'm using Spring Boot 2.5.4 and Jackson for JSON serialization, and I've configured my application with a custom ObjectMapper to handle date formats. However, despite my efforts, some LocalDateTime fields are not being serialized correctly, leading to missing data in my API responses. Here's what I have so far in my configuration: ```java @Bean public ObjectMapper objectMapper() { ObjectMapper mapper = new ObjectMapper(); mapper.registerModule(new JavaTimeModule()); mapper.configure(SerializationFeature.WRITE_DATES_AS_TIMESTAMPS, false); return mapper; } ``` In my entity, I have the following: ```java @Entity public class Event { @Id private Long id; private String name; @JsonFormat(pattern = "yyyy-MM-dd'T'HH:mm:ss.SSS") private LocalDateTime startTime; // getters and setters } ``` I've also tried adding the `@JsonFormat` annotation directly to the LocalDateTime field, but it seems that only some of the events return the correct serialized date while others return null. I verified that the database column is correctly populated with the expected timestamps. Additionally, I've checked that the LocalDateTime fields are never null when retrieved from the database. However, the response object seems to lose these values intermittently, particularly when sent in bulk requests. I suspect this might be related to the way Jackson handles serialization of Java 8 date types in certain contexts. Is there a specific configuration or additional annotation I should consider to ensure that the LocalDateTime values are consistently serialized in my API responses? Any insights into potential pitfalls or edge cases would be greatly appreciated!