Ignoring new fields on JSON objects using Jackson
In addition to 2 mechanisms already mentioned, there is also global feature that can be used to suppress all failures caused by unknown (unmapped) properties:
// jackson 1.9 and before
objectMapper.configure(DeserializationConfig.Feature.FAIL_ON_UNKNOWN_PROPERTIES, false);
// or jackson 2.0
objectMapper.configure(DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES, false);
This is the default used in absence of annotations, and can be convenient fallback.
Jackson provides an annotation that can be used on class level (JsonIgnoreProperties).
Add the following to the top of your class (not to individual methods):
@JsonIgnoreProperties(ignoreUnknown = true)
public class Foo {
...
}
Depending on the jackson version you are using you would have to use a different import in the current version it is:
import com.fasterxml.jackson.annotation.JsonIgnoreProperties;
in older versions it has been:
import org.codehaus.jackson.annotate.JsonIgnoreProperties;
Up to date and complete answer with Jackson 2
Using Annotation
import com.fasterxml.jackson.annotation.JsonIgnoreProperties;
@JsonIgnoreProperties(ignoreUnknown = true)
public class MyMappingClass {
}
See JsonIgnoreProperties on Jackson online documentation.
Using Configuration
Less intrusive than annotation.
import com.fasterxml.jackson.databind.DeserializationFeature;
import com.fasterxml.jackson.databind.ObjectMapper;
import com.fasterxml.jackson.databind.ObjectReader;
ObjectMapper objectMapper = new ObjectMapper();
objectMapper.configure(DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES, false);
ObjectReader objectReader = objectMapper.reader(MyMappingClass.class);
MyMappingClass myMappingClass = objectReader.readValue(json);
See FAIL_ON_UNKNOWN_PROPERTIES on Jackson online documentation.