JsonMappingException through nested getter with generic wildcard return type #2331
Description
Having the following Code, produces an Exception if i try to serialize it. Jackson v2.9.8.
Here is an Example-Project which fully reproduces the Error. Git-Project
public class Node<T extends SuperTestClass & Cloneable> extends SuperNode<Node<T>> implements Serializable {
public static void main(String[] args) throws JsonProcessingException {
Node root = new Node();
root.children.add(new Node());
System.out.println(new ObjectMapper().writeValueAsString(root));
}
public List<Node<T>> children;
public Node() {
children = new ArrayList<Node<T>>();
}
/**
* The Wildcard here seems to be the Issue.
* If we remove this full getter, everything is working as expected.
* @return
*/
public List<? extends SuperNode<Node<T>>> getChildren() {
return children;
}
}
com.fasterxml.jackson.databind.JsonMappingException: Index: 0 (through reference chain: com.test.Node["children"]->java.util.ArrayList[0])
at com.fasterxml.jackson.databind.JsonMappingException.wrapWithPath(JsonMappingException.java:394)
at com.fasterxml.jackson.databind.JsonMappingException.wrapWithPath(JsonMappingException.java:365)
at com.fasterxml.jackson.databind.ser.std.StdSerializer.wrapAndThrow(StdSerializer.java:338)
at com.fasterxml.jackson.databind.ser.impl.IndexedListSerializer.serializeContents(IndexedListSerializer.java:123)
at com.fasterxml.jackson.databind.ser.impl.IndexedListSerializer.serialize(IndexedListSerializer.java:79)
at com.fasterxml.jackson.databind.ser.impl.IndexedListSerializer.serialize(IndexedListSerializer.java:18)
at com.fasterxml.jackson.databind.ser.BeanPropertyWriter.serializeAsField(BeanPropertyWriter.java:727)
at com.fasterxml.jackson.databind.ser.std.BeanSerializerBase.serializeFields(BeanSerializerBase.java:719)
at com.fasterxml.jackson.databind.ser.BeanSerializer.serialize(BeanSerializer.java:155)
at com.fasterxml.jackson.databind.ser.DefaultSerializerProvider._serialize(DefaultSerializerProvider.java:480)
at com.fasterxml.jackson.databind.ser.DefaultSerializerProvider.serializeValue(DefaultSerializerProvider.java:319)
at com.fasterxml.jackson.databind.ObjectMapper._configAndWriteValue(ObjectMapper.java:3905)
at com.fasterxml.jackson.databind.ObjectMapper.writeValueAsString(ObjectMapper.java:3219)
at com.test.MainJackson.main(MainJackson.java:22)
Caused by: java.lang.IndexOutOfBoundsException: Index: 0
at java.util.Collections$EmptyList.get(Collections.java:4454)
at com.fasterxml.jackson.databind.type.TypeFactory._verifyAndResolvePlaceholders(TypeFactory.java:505)
at com.fasterxml.jackson.databind.type.TypeFactory._resolveTypePlaceholders(TypeFactory.java:458)
at com.fasterxml.jackson.databind.type.TypeFactory._bindingsForSubtype(TypeFactory.java:429)
at com.fasterxml.jackson.databind.type.TypeFactory.constructSpecializedType(TypeFactory.java:401)
at com.fasterxml.jackson.databind.cfg.MapperConfig.constructSpecializedType(MapperConfig.java:297)
at com.fasterxml.jackson.databind.DatabindContext.constructSpecializedType(DatabindContext.java:161)
at com.fasterxml.jackson.databind.ser.impl.IndexedListSerializer.serializeContents(IndexedListSerializer.java:113)
... 10 more
Please let me know if you need anything else from me.