java - How to annotate enum fields for deserialization using Jackson json

Question

I am using REST web service/Apache Wink with Jackson 1.6.2. How do I annotate an enum field so that Jackson deserializes it?

Inner class

public enum BooleanField
{
    BOOLEAN_TRUE        { public String value() { return "1";} },
    BOOLEAN_FALSE       { public String value() { return "0";} },

Java Bean/Request object

BooleanField locked;
public BooleanField getLocked() {return locked;}

The Jackson docs state that it can do this via @JsonValue/@JsonCreator but provides no examples.

Anyone willing to spill the (java)beans, as it were?

Answer 1

If you are using Jackson 1.9, serialization would be done by:

public enum BooleanField {
   BOOLEAN_TRUE("1")
   ;

   // either add @JsonValue here (if you don't need getter)
   private final String value;

   private BooleanField(String value) { this.value = value; }

   // or here
   @JsonValue public String value() { return value; }

so change you need is to add method to Enum type itself, so all values have it. Not sure if it would work on subtype.

For @JsonCreator, having a static factory method would do it; so adding something like:

@JsonCreator
public static BooleanField forValue(String v) { ... }

Jackson 2.0 will actually support use of just @JsonValue for both, including deserialization.