Unexpected InvalidTypeIdException when parsing XML to POJO containing nested List<> , custom TypeIdResolver #426
Description
XML Parsing fails with the complain that type id is missing, even when it is defined in the input xml
When 'uid' attribute is completely removed from the input xml, then the parsing works.
Java Code where problem can be reproduced with jackson-dataformat-xml 2.11.2
package com.temp; import java.io.IOException; import java.util.List; import com.fasterxml.jackson.annotation.JsonInclude; import com.fasterxml.jackson.annotation.JsonTypeInfo; import com.fasterxml.jackson.databind.DatabindContext; import com.fasterxml.jackson.databind.JavaType; import com.fasterxml.jackson.databind.SerializationFeature; import com.fasterxml.jackson.databind.annotation.JsonTypeIdResolver; import com.fasterxml.jackson.databind.jsontype.impl.TypeIdResolverBase; import com.fasterxml.jackson.dataformat.xml.XmlMapper; import com.fasterxml.jackson.dataformat.xml.annotation.JacksonXmlElementWrapper; import com.fasterxml.jackson.dataformat.xml.annotation.JacksonXmlProperty; public class AutoParser { public static void main(String[] args) throws Exception { String xml = "" + "<Auto>\n" + " <Object uid=\"1\" type=\"Engine\">\n" + " <Object uid=\"2\" type=\"Chassis\"></Object>\n" + " <Object uid=\"3\" type=\"Motor\"></Object>\n" + " </Object>\n" + " <Object uid=\"4\" type=\"Body\"></Object>\n" + "</Auto>"; XmlMapper xmlMapper = new XmlMapper(); Auto auto = xmlMapper.readValue(xml, Auto.class); xmlMapper.configure(SerializationFeature.INDENT_OUTPUT, true); System.out.println(xmlMapper.writeValueAsString(auto)); } } class Auto { @JacksonXmlProperty(localName = "Object") @JacksonXmlElementWrapper(useWrapping = false) @JsonInclude(JsonInclude.Include.NON_EMPTY) List<CarParts> carParts; } @JsonTypeIdResolver(CarPartsResolver.class) @JsonTypeInfo(use = JsonTypeInfo.Id.CUSTOM, include = JsonTypeInfo.As.PROPERTY, property = "type") abstract class CarParts { @JacksonXmlProperty(isAttribute = true) // The is triggering the issue. String uid; @JacksonXmlProperty(localName = "Object") @JacksonXmlElementWrapper(useWrapping = false) @JsonInclude(JsonInclude.Include.NON_EMPTY) List<CarParts> carParts; } class Engine extends CarParts{} class Chassis extends CarParts{} class Motor extends CarParts{} class Body extends CarParts{} class CarPartsResolver extends TypeIdResolverBase { private JavaType superType; @Override public void init(JavaType javaType) { this.superType = javaType; } @Override public String idFromValue(Object o) { return idFromValueAndType(o, o.getClass()); } @Override public String idFromValueAndType(Object o, Class<?> aClass) { return aClass.getSimpleName(); } @Override public JavaType typeFromId(DatabindContext context, String id) throws IOException { Class<?> subType = null; switch (id) { case "Engine": subType = Engine.class; break; case "Chassis": subType = Chassis.class; break; case "Motor": subType = Motor.class; break; case "Body": subType = Body.class; break; } return context.constructSpecializedType(superType, subType); } @Override public JsonTypeInfo.Id getMechanism() { return JsonTypeInfo.Id.CUSTOM; } } Stacktrace
Exception in thread "main" com.fasterxml.jackson.databind.exc.InvalidTypeIdException: Missing type id when trying to resolve subtype of [simple type, class com.temp.CarParts]: missing type id property 'type' (for POJO property 'Object') at [Source: (StringReader); line: 3, column: 40] (through reference chain: com.temp.Auto["Object"]->java.util.ArrayList[0]->com.temp.Engine["Object"]->java.util.ArrayList[0]) at com.fasterxml.jackson.databind.exc.InvalidTypeIdException.from(InvalidTypeIdException.java:43) at com.fasterxml.jackson.databind.DeserializationContext.missingTypeIdException(DeserializationContext.java:1794) at com.fasterxml.jackson.databind.DeserializationContext.handleMissingTypeId(DeserializationContext.java:1323) at com.fasterxml.jackson.databind.jsontype.impl.TypeDeserializerBase._handleMissingTypeId(TypeDeserializerBase.java:303) at com.fasterxml.jackson.databind.jsontype.impl.AsPropertyTypeDeserializer._deserializeTypedUsingDefaultImpl(AsPropertyTypeDeserializer.java:166) at com.fasterxml.jackson.databind.jsontype.impl.AsPropertyTypeDeserializer.deserializeTypedFromObject(AsPropertyTypeDeserializer.java:107) at com.fasterxml.jackson.databind.deser.AbstractDeserializer.deserializeWithType(AbstractDeserializer.java:254) at com.fasterxml.jackson.databind.deser.std.CollectionDeserializer.deserialize(CollectionDeserializer.java:293) at com.fasterxml.jackson.databind.deser.std.CollectionDeserializer.deserialize(CollectionDeserializer.java:250) at com.fasterxml.jackson.databind.deser.std.CollectionDeserializer.deserialize(CollectionDeserializer.java:27) at com.fasterxml.jackson.databind.deser.impl.FieldProperty.deserializeAndSet(FieldProperty.java:138) at com.fasterxml.jackson.databind.deser.BeanDeserializer.vanillaDeserialize(BeanDeserializer.java:293) PS: Above code is able to parse following XMLs
<Auto> <Object type="Engine"> <Object type="Chassis"></Object> <Object type="Motor"></Object> </Object> <Object type="Body"></Object> </Auto> <Auto> <Object uid="1" type="Engine"></Object> <Object uid="4" type="Body"></Object> </Auto> but fails on
<Auto> <Object uid="1" type="Engine"> <Object uid="2" type="Chassis"></Object> <Object uid="3" type="Motor"></Object> </Object> <Object uid="4" type="Body"></Object> </Auto>