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NPE with `CollectionDeserializer` with `TreeSet` class, with input `null`

See original GitHub issue

Hello,

I’ve a problem while trying deserialize a TreeSet with a custom deserializer, in my situation deserializer not find the registry to add the collection, and returns null, but as TreeSet does not accept nulls, pops exception in Java, as below:

com.fasterxml.jackson.databind.JsonMappingException: (was java.lang.NullPointerException) (through reference chain: com.framework.entity.dynamic.DocumentEntityInfo["folders"]->java.util.TreeSet[0])
    at com.fasterxml.jackson.databind.JsonMappingException.wrapWithPath(JsonMappingException.java:378)
    at com.fasterxml.jackson.databind.JsonMappingException.wrapWithPath(JsonMappingException.java:350)
    at com.fasterxml.jackson.databind.deser.std.CollectionDeserializer.deserialize(CollectionDeserializer.java:298)
    at com.fasterxml.jackson.databind.deser.std.CollectionDeserializer.deserialize(CollectionDeserializer.java:249)
    at com.fasterxml.jackson.databind.deser.std.CollectionDeserializer.deserialize(CollectionDeserializer.java:26)
    at com.fasterxml.jackson.databind.deser.SettableBeanProperty.deserialize(SettableBeanProperty.java:490)
    at com.fasterxml.jackson.databind.deser.impl.MethodProperty.deserializeAndSet(MethodProperty.java:95)
    at com.fasterxml.jackson.databind.deser.BeanDeserializer.vanillaDeserialize(BeanDeserializer.java:260)
    at com.fasterxml.jackson.databind.deser.BeanDeserializer._deserializeOther(BeanDeserializer.java:163)
    at com.fasterxml.jackson.databind.deser.BeanDeserializer.deserialize(BeanDeserializer.java:135)
    at com.fasterxml.jackson.databind.jsontype.impl.AsPropertyTypeDeserializer._deserializeTypedForId(AsPropertyTypeDeserializer.java:120)
    at com.fasterxml.jackson.databind.jsontype.impl.AsPropertyTypeDeserializer.deserializeTypedFromObject(AsPropertyTypeDeserializer.java:91)
    at com.fasterxml.jackson.databind.jsontype.impl.AsPropertyTypeDeserializer.deserializeTypedFromAny(AsPropertyTypeDeserializer.java:163)
    at com.fasterxml.jackson.databind.deser.impl.TypeWrappedDeserializer.deserialize(TypeWrappedDeserializer.java:42)
    at com.fasterxml.jackson.databind.ObjectMapper._readMapAndClose(ObjectMapper.java:3807)
    at com.fasterxml.jackson.databind.ObjectMapper.readValue(ObjectMapper.java:2797)
Caused by: java.lang.NullPointerException
    at java.util.TreeMap.compare(TreeMap.java:1290)
    at java.util.TreeMap.put(TreeMap.java:538)
    at java.util.TreeSet.add(TreeSet.java:255)
    at com.fasterxml.jackson.databind.deser.std.CollectionDeserializer.deserialize(CollectionDeserializer.java:284)

The suggestion is to treat null for this situation in the Collection Deserializer, and not add the item in the list in return. Line 284 of CollectionDeserializer class.

https://github.com/FasterXML/jackson-databind/blob/master/src/main/java/com/fasterxml/jackson/databind/deser/std/CollectionDeserializer.java

I’ve searched for an issue linked to that, without success in the issue tracker.

Thanks for your help.

Issue Analytics

State:
Created 7 years ago
Reactions:1
Comments:5 (4 by maintainers)

Top GitHub Comments

1reaction

cowtowncodercommented, Oct 14, 2016

Actually while I do not like one-off feature for null handling for just collections, I think it would be valid to block null from TreeSet, given that it can not work with JDK.

0reactions

cowtowncodercommented, Nov 19, 2016

Actually closing as it should be handled via #1402, and I have no plans for type-specific hack.

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