👀 Views: 184 💬 Answers: 1 📅 Created: 2025-06-12

jackson spring-boot json deserialization Java

Hey everyone, I'm running into an issue that's driving me crazy. I'm stuck trying to Quick question that's been bugging me - I'm working on a personal project and I'm working on a personal project and I'm working with a question with Jackson when trying to deserialize nested objects using the `@JsonCreator` annotation in a Spring Boot application... My model class has a nested object, and I'm using a constructor to initialize it. However, I'm getting a `com.fasterxml.jackson.databind.exc.ValueInstantiationException` behavior, which indicates that Jackson want to instantiate my class. Here's a simplified version of my code: ```java public class Outer { private final Inner inner; @JsonCreator public Outer(@JsonProperty("inner") Inner inner) { this.inner = inner; } public Inner getInner() { return inner; } } public class Inner { private final String name; @JsonCreator public Inner(@JsonProperty("name") String name) { this.name = name; } public String getName() { return name; } } ``` When I send a JSON payload like this: ```json { "inner": { "name": "Example" } } ``` I receive the following behavior: ``` com.fasterxml.jackson.databind.exc.ValueInstantiationException: want to construct instance of `Outer`, question: want to construct instance of `Inner` ``` I've verified that my JSON matches the expected structure of my classes. I've also tried adding `@JsonProperty` to the constructor parameters in the `Inner` class but it doesn't seem to resolve the scenario. Additionally, I confirmed that the Jackson dependency version is `2.11.0`, which is compatible with my Spring Boot version `2.5.0`. I've looked through the documentation but need to find anything that addresses this specific scenario. Any insights into what could be going wrong would be greatly appreciated. How would you solve this? Thanks in advance! I recently upgraded to Java 3.10. I'm coming from a different tech stack and learning Java. I appreciate any insights! Am I missing something obvious?