JSON Jackson custom deserializer to return empty String instead of null

Needed a way to deserialize null values in a JSON as emptry strings (""). This is the shortest I could come with.

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import com.fasterxml.jackson.core.JsonParser; import com.fasterxml.jackson.databind.DeserializationContext; import com.fasterxml.jackson.databind.ObjectMapper; import com.fasterxml.jackson.databind.deser.std.UntypedObjectDeserializer; import com.fasterxml.jackson.databind.module.SimpleModule;   public class NullHandlerDeserializer extends UntypedObjectDeserializer {     private static final long serialVersionUID = 1L;     @Override   public Object deserialize(JsonParser jp, DeserializationContext ctxt)     throws IOException {     switch (jp.getCurrentToken()) {      case VALUE_NULL:            return "";      default:       return super.deserialize(jp, ctxt);     }     }  }

The class extends from an existing deserializer implementation to avoid having to code the handling of all JSON tokens. I needed to worry only about VALUE_NULL token.

And to configure the custom deserializer in the ObjectMapper:

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ObjectMapper om = new ObjectMapper(); SimpleModule module = new SimpleModule(); module.addDeserializer(Object.class, new NullHandlerDeserializer()); om.registerModule(module);