com.fasterxml.jackson.databind.annotation

Annotation Type JsonDeserialize


  • @Target(value={ANNOTATION_TYPE,METHOD,FIELD,TYPE,PARAMETER})
 @Retention(value=RUNTIME)
public @interface JsonDeserialize
    Annotation use for configuring deserialization aspects, by attaching to "setter" methods or fields, or to value classes. When annotating value classes, configuration is used for instances of the value class but can be overridden by more specific annotations (ones that attach to methods or fields).

    An example annotation would be: 

      @JsonDeserialize(using=MySerializer.class,
    as=MyHashMap.class,
    keyAs=MyHashKey.class,
    contentAs=MyHashValue.class
  )

    Something to note on usage:

    • All other annotations regarding behavior during building should be on Builder class and NOT on target POJO class: for example @JsonIgnoreProperties should be on Builder to prevent "unknown property" errors.
    • Similarly configuration overrides (see ObjectMapper.configOverride(java.lang.Class<?>)) should be targeted at Builder class, not target POJO class.

    • Optional Element Summary

      Optional Elements 
      Modifier and Type Optional Element and Description
      Class<?> as
      Concrete type to deserialize values as, instead of type otherwise declared.
      Class<?> builder
      Annotation for specifying if an external Builder class is to be used for building up deserialized instances of annotated class.
      Class<?> contentAs
      Concrete type to deserialize content (elements of a Collection/array, values of Maps) values as, instead of type otherwise declared.
      Class<? extends Converter> contentConverter
      Similar to converter(), but used for values of structures types (List, arrays, Maps).
      Class<? extends JsonDeserializer> contentUsing
      Deserializer class to use for deserializing contents (elements of a Collection/array, values of Maps) of annotated property.
      Class<? extends Converter> converter
      Which helper object (if any) is to be used to convert from Jackson-bound intermediate type (source type of converter) into actual property type (which must be same as result type of converter).
      Class<?> keyAs
      Concrete type to deserialize keys of Map as, instead of type otherwise declared.
      Class<? extends KeyDeserializer> keyUsing
      Deserializer class to use for deserializing Map keys of annotated property or Map keys of value type so annotated.
      Class<? extends JsonDeserializer> using
      Deserializer class to use for deserializing associated value.

    • Element Detail

      • using

        public abstract Class<? extends JsonDeserializer> using
        Deserializer class to use for deserializing associated value. Depending on what is annotated, value is either an instance of annotated class (used globablly anywhere where class deserializer is needed); or only used for deserializing the value of the property annotated.
        Default:
        com.fasterxml.jackson.databind.JsonDeserializer.None.class

      • contentUsing

        public abstract Class<? extends JsonDeserializer> contentUsing
        Deserializer class to use for deserializing contents (elements of a Collection/array, values of Maps) of annotated property. Can only be used on accessors (methods, fields, constructors), to apply to values of Map-valued properties; not applicable for value types used as Array elements or Collection and Map values.
        Default:
        com.fasterxml.jackson.databind.JsonDeserializer.None.class

      • keyUsing

        public abstract Class<? extends KeyDeserializer> keyUsing
        Deserializer class to use for deserializing Map keys of annotated property or Map keys of value type so annotated. Can be used both on accessors (methods, fields, constructors), to apply to values of Map-valued properties, and on "key" classes, to apply to use of annotated type as Map keys (latter starting with Jackson 2.11).
        Default:
        com.fasterxml.jackson.databind.KeyDeserializer.None.class

      • builder

        public abstract Class<?> builder
        Annotation for specifying if an external Builder class is to be used for building up deserialized instances of annotated class. If so, an instance of referenced class is first constructed (possibly using a Creator method; or if none defined, using default constructor), and its "with-methods" are used for populating fields; and finally "build-method" is invoked to complete deserialization.
        Default:
        java.lang.Void.class

      • converter

        public abstract Class<? extends Converter> converter
        Which helper object (if any) is to be used to convert from Jackson-bound intermediate type (source type of converter) into actual property type (which must be same as result type of converter). This is often used for two-step deserialization; Jackson binds data into suitable intermediate type (like Tree representation), and converter then builds actual property type.
        Since:
        2.2
        Default:
        com.fasterxml.jackson.databind.util.Converter.None.class

      • contentConverter

        public abstract Class<? extends Converter> contentConverter
        Similar to converter(), but used for values of structures types (List, arrays, Maps).
        Since:
        2.2
        Default:
        com.fasterxml.jackson.databind.util.Converter.None.class

      • as

        public abstract Class<?> as
        Concrete type to deserialize values as, instead of type otherwise declared. Must be a subtype of declared type; otherwise an exception may be thrown by deserializer.

        Bogus type Void can be used to indicate that declared type is used as is (i.e. this annotation property has no setting); this since annotation properties are not allowed to have null value.

        Note: if using() is also used it has precedence (since it directly specified deserializer, whereas this would only be used to locate the deserializer) and value of this annotation property is ignored.

        Default:
        java.lang.Void.class

      • keyAs

        public abstract Class<?> keyAs
        Concrete type to deserialize keys of Map as, instead of type otherwise declared. Must be a subtype of declared type; otherwise an exception may be thrown by deserializer.
        Default:
        java.lang.Void.class

      • contentAs

        public abstract Class<?> contentAs
        Concrete type to deserialize content (elements of a Collection/array, values of Maps) values as, instead of type otherwise declared. Must be a subtype of declared type; otherwise an exception may be thrown by deserializer.
        Default:
        java.lang.Void.class

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