Jackson JSON gives exception on collection of nested class

Question

Jackson JSON has no problem serializing/deserializing this class:

public class MyClass {
   public class Nested {
      public String string;
      public Ne         


        

Answer 1

Looks like the recognition of non-static inner classes is done where they are properties directly on their containing bean (BeanDeserializerBase.java line 476 in 2.6.3). So an intervening Collection deserializer would go past that. A custom deserializer is likely the simplest option here.

Note that you can still use Jackson to read the properties of Nested, and just implement the construction of it yourself, in a custom deserializer only used when deserializing a list of Nested objects.

To do this, annotate the list like so:

    @JsonDeserialize(contentUsing = NestedDeserializer.class)
    public List nestedList;

and then use a custom deserializer that will:

1. Look at the parsing context when called to find the containing MyClass instance.

2. Encapsulate a default/root-level deserializer of Nested to delegate the work of deserializing the content to.

For example:

public static final class NestedDeserializer extends StdDeserializer
    implements ResolvableDeserializer {
  private JsonDeserializer