Difficulty Implementing Custom Jackson Serializer for LocalDate in Java 17 with Spring Boot
I'm upgrading from an older version and I'm working on a personal project and I'm trying to implement a custom serializer for `LocalDate` using Jackson in my Spring Boot application... The default serialization is returning dates in the format `YYYY-MM-DD`, but I need it to be formatted as `DD/MM/YYYY` for compatibility with our front-end. I've created a `LocalDateSerializer` class, but when I run the application, I receive the following error: ``` com.fasterxml.jackson.databind.JsonMappingException: Invalid format: "01/12/2023" is malformed at "01/" ``` Here’s the code I’ve written for the serializer: ```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 final DateTimeFormatter formatter = DateTimeFormatter.ofPattern("dd/MM/yyyy"); @Override public void serialize(LocalDate date, JsonGenerator gen, SerializerProvider serializers) throws IOException { gen.writeString(date.format(formatter)); } } ``` I've also registered this serializer in my `SpringBootApplication` like this: ```java import com.fasterxml.jackson.databind.ObjectMapper; import com.fasterxml.jackson.databind.module.SimpleModule; import org.springframework.boot.SpringApplication; import org.springframework.boot.autoconfigure.SpringBootApplication; import org.springframework.context.annotation.Bean; @SpringBootApplication public class MyApplication { public static void main(String[] args) { SpringApplication.run(MyApplication.class, args); } @Bean public ObjectMapper objectMapper() { SimpleModule module = new SimpleModule(); module.addSerializer(LocalDate.class, new LocalDateSerializer()); return new ObjectMapper().registerModule(module); } } ``` I’ve ensured that the `ObjectMapper` is being used by all my controllers, but the error persists. Additionally, I've tried using `@JsonSerialize(using = LocalDateSerializer.class)` directly on the `LocalDate` fields in my model classes, but that didn't seem to resolve the serialization issue either. What am I missing here? Is there a better way to achieve the date formatting I need, or could there be a configuration issue in my Spring Boot setup? The stack includes Java and several other technologies.