Class ObjectId

java.lang.Object
org.apache.cayenne.ObjectId
All Implemented Interfaces:
Serializable

public class ObjectId
extends Object
implements Serializable
A portable global identifier for persistent objects. ObjectId can be temporary (used for transient or new uncommitted objects) or permanent (used for objects that have been already stored in DB). A temporary ObjectId stores object entity name and a pseudo-unique binary key; permanent id stores a map of values from an external persistent store (aka "primary key").
See Also:
Serialized Form
  • Field Details

    • entityName

      protected String entityName
    • objectIdKeys

      protected Map<String,​Object> objectIdKeys
    • key

      protected byte[] key
    • replacementIdMap

      protected Map<String,​Object> replacementIdMap
  • Constructor Details

    • ObjectId

      public ObjectId​(String entityName)
      Creates a TEMPORARY ObjectId. Assigns a generated unique key.
      Since:
      1.2
    • ObjectId

      public ObjectId​(String entityName, byte[] key)
      Creates a TEMPORARY id with a specified entity name and a binary key. It is a caller responsibility to provide a globally unique binary key.
      Since:
      1.2
    • ObjectId

      public ObjectId​(String entityName, String key, int value)
      Creates a portable permanent ObjectId.
      Parameters:
      entityName - The entity name which this object id is for
      key - A key describing this object id, usually the attribute name for the primary key
      value - The unique value for this object id
      Since:
      1.2
    • ObjectId

      public ObjectId​(String entityName, String key, Object value)
      Creates a portable permanent ObjectId.
      Parameters:
      entityName - The entity name which this object id is for
      key - A key describing this object id, usually the attribute name for the primary key
      value - The unique value for this object id
      Since:
      1.2
    • ObjectId

      public ObjectId​(String entityName, Map<String,​?> idMap)
      Creates a portable permanent ObjectId as a compound primary key.
      Parameters:
      entityName - The entity name which this object id is for
      idMap - Keys are usually the attribute names for each part of the primary key. Values are unique when taken as a whole.
      Since:
      1.2
  • Method Details

    • isTemporary

      public boolean isTemporary()
      Is this is temporary object id (used for objects which are not yet persisted to the data store).
    • getEntityName

      public String getEntityName()
      Since:
      1.2
    • getKey

      public byte[] getKey()
      Get the binary temporary object id. Null if this object id is permanent (persisted to the data store).
    • getIdSnapshot

      public Map<String,​Object> getIdSnapshot()
      Returns an unmodifiable Map of persistent id values, essentially a primary key map. For temporary id returns replacement id, if it was already created. Otherwise returns an empty map.
    • equals

      public boolean equals​(Object object)
      Overrides:
      equals in class Object
    • hashCode

      public int hashCode()
      Overrides:
      hashCode in class Object
    • getReplacementIdMap

      public Map<String,​Object> getReplacementIdMap()
      Returns a non-null mutable map that can be used to append replacement id values. This allows to incrementally build a replacement GlobalID.
      Since:
      1.2
    • createReplacementId

      public ObjectId createReplacementId()
      Creates and returns a replacement ObjectId. No validation of ID is done.
      Since:
      1.2
    • isReplacementIdAttached

      public boolean isReplacementIdAttached()
      Returns true if there is full or partial replacement id attached to this id. This method is preferrable to "!getReplacementIdMap().isEmpty()" as it avoids unneeded replacement id map creation.
    • toString

      public String toString()
      A standard toString method used for debugging. It is guaranteed to produce the same string if two ObjectIds are equal.
      Overrides:
      toString in class Object