org.apache.geode.cache.query.types

## Interface CollectionType

- All Superinterfaces:
    DataSerializable, ObjectType, java.io.Serializable
  All Known Subinterfaces:
    MapType

      public interface CollectionType
      extends ObjectType

  Represents the type of a collection, an object that can contain element objects.
  Since:
    GemFire 4.0

- - ### Nested Class Summary

    - ### Nested classes/interfaces inherited from interface org.apache.geode.DataSerializable

      `DataSerializable.Replaceable`

  - ### Method Summary

    All Methods Instance Methods Abstract Methods
    Modifier and Type | Method and Description
    --- | ---
    `boolean` | `allowsDuplicates()` Return whether duplicates are kept in this type of collection.
    `ObjectType` | `getElementType()` Return the type of the elements of this collection type.
    `boolean` | `isOrdered()` Return whether this collection type has ordered elements.

    - ### Methods inherited from interface org.apache.geode.cache.query.types.ObjectType

      `getSimpleClassName, isCollectionType, isMapType, isStructType, resolveClass`

    - ### Methods inherited from interface org.apache.geode.DataSerializable

      `fromData, toData`

- - ### Method Detail

    - #### getElementType

          ObjectType getElementType()

      Return the type of the elements of this collection type.

    - #### allowsDuplicates

          boolean allowsDuplicates()

      Return whether duplicates are kept in this type of collection. Duplicates are two objects are equal to each other as defined by the `equals` method.
      Returns:
        true if duplicates have been retained, false if duplicates have been eliminated

    - #### isOrdered

          boolean isOrdered()

      Return whether this collection type has ordered elements.
      Returns:
        true if this collection type is ordered, false if not