Package org.eclipse.ditto.json

Interface JsonField

public interface JsonField
Represents a single JSON field. A JSON field in its simplest form is a key-value-pair. Additionally a field can be aware of its definition which allows to obtain meta information like the Java type of the value or the markers of the field. A JSON object, for example, can be understood as a tree of JSON fields.

Implementations of this interface are required to be immutable!

  • Method Details

    • newInstance

      static JsonField newInstance(CharSequence key, @Nullable JsonValue value)
      Returns a new JSON field based on the specified key value pair.
      Parameters:
      key - the key of the field to be created.
      value - the value of the field to be created. null will be converted to the JSON NULL Literal.
      Returns:
      a new JSON field containing the specified key value pair.
      Throws:
      NullPointerException - if key is null.

    • newInstance

      static JsonField newInstance(CharSequence key, @Nullable JsonValue value, @Nullable JsonFieldDefinition<?> definition)
      Returns a new JSON field based on the specified key value pair and definition.
      Parameters:
      key - the key of the field to be created.
      value - the value of the field to be created. null will be converted to the JSON NULL Literal.
      definition - the definition of the field to be created.
      Returns:
      a new JSON field containing the specified key value pair and definition.
      Throws:
      NullPointerException - if key is null.

    • isValueNonNull

      static Predicate<JsonField> isValueNonNull()
      Returns a Predicate for testing if the value of a JSON field is null.
      Returns:
      the predicate.
      See Also:

    • getKeyName

      String getKeyName()
      Returns the name of this JSON field's key.
      Returns:
      the name of this field's key.

    • getKey

      JsonKey getKey()
      Returns this JSON field's key.
      Returns:
      the key of this field.

    • getValue

      JsonValue getValue()
      Returns this JSON field's value.
      Returns:
      the value of this field.

    • getDefinition

      Optional<JsonFieldDefinition> getDefinition()
      Returns this JSON field's definition (meta-information).
      Returns:
      the definition of this field.

    • isMarkedAs

      boolean isMarkedAs(JsonFieldMarker fieldMarker, JsonFieldMarker... furtherFieldMarkers)
      Indicates whether this field is marked with at least all specified markers. This method can only return true if it has a definition.
      Parameters:
      fieldMarker - the mandatory fieldMarker to check this field for.
      furtherFieldMarkers - additional markers to check this field for.
      Returns:
      true if this field is marked with at least all specified markers, false else.
      Throws:
      NullPointerException - if any argument is null.

    • writeKeyAndValue

      void writeKeyAndValue(SerializationContext serializationContext) throws IOException
      Writes this JsonField's key and value into the provided serialization context. This is intended to be used by serialization logic only.
      Parameters:
      serializationContext - the context for serialization bundling configuration and state needed for serialization.
      Throws:
      IOException - in case writing the value to the backing OutputStream causes an IOException.
      Since:
      1.1.0