Hi,
I have a case where a map is used to store many sets of values.
Map<String, Set<?>>
Each set instance is a set of homogenous data types. But the different
entries in the map hold a heterogenous collection of set types. Difficult
to put in to English, but the example code below is actually quite simple.
The description here is to imply that the set always has to be Set<?> and
can't be fully typed.
Obviously, to successfully deserialize such a heterogeneous map, type
information must be included in the serialized Json. This is achievable by
configuring the ObjectMapper. For example,
mapper.enableDefaultTyping( );
means all type information is recorded in the serialized JSON. However,
I'm trying to use @JonTypeInfo attribute so that callers of our library do
not need to remember to use a correctly configured ObjectMapper.
JsonTypeInfo seems to work for a simple set, but does not work when applied
to the map ...
public class MyTest
{
@JsonTypeInfo(
use = JsonTypeInfo.Id.CLASS,
include = JsonTypeInfo.As.PROPERTY,
property = "@type",
visible = true
)
public enum MyEnum
{
ONE,
TWO,
THREE
}
@JsonAutoDetect( fieldVisibility = JsonAutoDetect.Visibility.NONE,
getterVisibility = JsonAutoDetect.Visibility.NONE, setterVisibility =
JsonAutoDetect.Visibility.NONE, isGetterVisibility =
JsonAutoDetect.Visibility.NONE )
public static class MyClass
{
@JsonProperty( )
MyEnum singleEnum;
@JsonTypeInfo(
use = JsonTypeInfo.Id.CLASS,
include = JsonTypeInfo.As.PROPERTY,
property = "@type",
visible = true
)
@JsonProperty( )
Set<?> enumSet;
@JsonProperty( )
@JsonTypeInfo(
use = JsonTypeInfo.Id.CLASS,
include = JsonTypeInfo.As.PROPERTY,
property = "@type",
visible = true
)
Map<String, Set<?>> mapOfEnumSets = new LinkedHashMap<>( );
}
public static void main( String[] args ) throws JsonProcessingException
{
MyClass mc = new MyClass( );
mc.singleEnum = MyEnum.TWO;
mc.enumSet = Stream.of( MyEnum.ONE, MyEnum.TWO, MyEnum.THREE
).collect( Collectors.toSet( ) );
mc.mapOfEnumSets.put( "firstKey", Stream.of( MyEnum.ONE,
MyEnum.TWO, MyEnum.THREE ).collect( Collectors.toSet( ) ) );
ObjectMapper om = new ObjectMapper( );
String jsonString = om.writeValueAsString( mc );
System.out.println( jsonString );
}
}
This is the serialized JSON:
{"singleEnum":["MyTest$MyEnum","TWO"],"enumSet":[["MyTest$MyEnum","TWO"],["MyTest$MyEnum","THREE"],["MyTest$MyEnum","ONE"]],"mapOfEnumSets":{"firstKey":["java.util.HashSet",["TWO","THREE","ONE"]]}}
.
Is it possible to get the type info generated for the contents of the sets
in the map using JsonTypeInfo and/or other annotations? Or are we limited
to the direct configuration of the ObjectMapper?
Thanks
Mark
--
You received this message because you are subscribed to the Google Groups
"jackson-user" group.
To unsubscribe from this group and stop receiving emails from it, send an email
to [email protected].
To view this discussion on the web visit
https://groups.google.com/d/msgid/jackson-user/CAG%3D-QZM_M%3DvJs9e_c8OQt2fzhHinQAO68m85cpwvP6rVff5RxA%40mail.gmail.com.
