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How can I tell jackson to ignore a property for which I don't have control over the source code?

Tags:

java

json

jackson

People also ask

How do I ignore properties in Jackson?

Ignore All Fields by Type Finally, we can ignore all fields of a specified type, using the @JsonIgnoreType annotation. If we control the type, then we can annotate the class directly: @JsonIgnoreType public class SomeType { ... }

How do you tell Jackson to ignore a field during serialization?

If there are fields in Java objects that do not wish to be serialized, we can use the @JsonIgnore annotation in the Jackson library. The @JsonIgnore can be used at the field level, for ignoring fields during the serialization and deserialization.

How do I ignore properties in JSON?

To ignore individual properties, use the [JsonIgnore] attribute. You can specify conditional exclusion by setting the [JsonIgnore] attribute's Condition property. The JsonIgnoreCondition enum provides the following options: Always - The property is always ignored.

How do I ignore a field in JSON response Jackson?

The Jackson @JsonIgnore annotation can be used to ignore a certain property or field of a Java object. The property can be ignored both when reading JSON into Java objects and when writing Java objects into JSON.


You can use Jackson Mixins. For example:

class YourClass {
  public int ignoreThis() { return 0; }    
}

With this Mixin

abstract class MixIn {
  @JsonIgnore abstract int ignoreThis(); // we don't need it!  
}

With this:

objectMapper.getSerializationConfig().addMixInAnnotations(YourClass.class, MixIn.class);

Edit:

Thanks to the comments, with Jackson 2.5+, the API has changed and should be called with objectMapper.addMixIn(Class<?> target, Class<?> mixinSource)


One other possibility is, if you want to ignore all unknown properties, you can configure the mapper as follows:

mapper.configure(DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES, false);

Using Java Class

new ObjectMapper().configure(DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES, false)

Using Annotation

@JsonIgnoreProperties(ignoreUnknown=true)

Annotation based approach is better. But sometimes manual operation is needed. For this purpose you can use without method of ObjectWriter.

ObjectMapper mapper   = new ObjectMapper().configure(DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES, false)
ObjectWriter writer   = mapper.writer().withoutAttribute("property1").withoutAttribute("property2");
String       jsonText = writer.writeValueAsString(sourceObject);