👀 Views: 39 💬 Answers: 1 📅 Created: 2025-06-07

java jackson localdate serialization Java

I'm a bit lost with I'm trying to debug I'm getting frustrated with I'm working with an scenario when trying to serialize a `LocalDate` field in my Java 17 application using Jackson. I've created a custom serializer for `LocalDate`, but it seems to be serializing the date in an unexpected format, even though I've specified the desired format. Here's the serializer I implemented: ```java import com.fasterxml.jackson.core.JsonGenerator; import com.fasterxml.jackson.databind.JsonSerializer; import com.fasterxml.jackson.databind.SerializerProvider; import java.io.IOException; import java.time.LocalDate; import java.time.format.DateTimeFormatter; public class LocalDateSerializer extends JsonSerializer<LocalDate> { private static final DateTimeFormatter formatter = DateTimeFormatter.ofPattern("yyyy-MM-dd"); @Override public void serialize(LocalDate date, JsonGenerator generator, SerializerProvider serializers) throws IOException { if (date != null) { generator.writeString(date.format(formatter)); } } } ``` I registered this serializer with my `ObjectMapper` as follows: ```java import com.fasterxml.jackson.databind.ObjectMapper; import com.fasterxml.jackson.databind.module.SimpleModule; import java.time.LocalDate; public class App { public static void main(String[] args) throws Exception { ObjectMapper mapper = new ObjectMapper(); SimpleModule module = new SimpleModule(); module.addSerializer(LocalDate.class, new LocalDateSerializer()); mapper.registerModule(module); String json = mapper.writeValueAsString(LocalDate.now()); System.out.println(json); } } ``` When I run the above code, I expect the output to be something like "2023-10-05", but instead, I receive an output that looks like this: "2023-10-05T00:00:00.000". I did not include any time component in my `LocalDate` serializer, so I find this behavior confusing. I've also tried using different versions of Jackson (2.12.0 and 2.13.0), but the question continues. Could anyone guide to understand why this is happening and how to resolve it effectively? My goal is to have a clean `yyyy-MM-dd` format without any time component included. I've been using Java for about a year now. I've been using Java for about a year now. Any examples would be super helpful.