Package org.datanucleus.identity

Class IdentityUtils

  • public class IdentityUtils
extends java.lang.Object
    Series of utilities for handling identities of objects.

    • Constructor Detail

      • IdentityUtils

        public IdentityUtils()

    • Method Detail

      • isSingleFieldIdentityClass

        public static boolean isSingleFieldIdentityClass​(java.lang.String className)
        Checks whether the passed class name is valid for a single field application-identity.
        Parameters:
        className - the identity class name
        Returns:
        Whether it is a single field class

      • getTargetClassNameForIdentity

        public static java.lang.String getTargetClassNameForIdentity​(java.lang.Object id)
        Method to return the target class name of the persistable object that the provided identity represents. For the cases of datastore-identity or single-field identity then utilises the accessor method on those identity types to get the targetClassName. For user-provided identity types checks for a 
        targetClassName
        field and returns it if present. Otherwise returns null.
        Parameters:
        id - The identity
        Returns:
        Class name for the identity if easily determinable

      • isSingleFieldIdentity

        public static boolean isSingleFieldIdentity​(java.lang.Object id)
        Accessor for whether the passed identity is a valid single-field application-identity for this API.
        Parameters:
        id - The id
        Returns:
        Whether it is valid

      • isDatastoreIdentity

        public static boolean isDatastoreIdentity​(java.lang.Object id)
        Accessor for whether the provided id is datastore identity.
        Parameters:
        id - The identity to check
        Returns:
        Whether it is datastore identity

      • getTargetKeyForSingleFieldIdentity

        public static java.lang.Object getTargetKeyForSingleFieldIdentity​(java.lang.Object id)
        Accessor for the key object for the specified single field application-identity.
        Parameters:
        id - The identity
        Returns:
        The key object

      • getTargetKeyForDatastoreIdentity

        public static java.lang.Object getTargetKeyForDatastoreIdentity​(java.lang.Object id)
        Accessor for the key object for the specified datastore-identity.
        Parameters:
        id - The identity
        Returns:
        The key object

      • getSingleFieldIdentityTypeForKeyType

        public static java.lang.Class<? extends SingleFieldId> getSingleFieldIdentityTypeForKeyType​(java.lang.Class keyType)

      • getKeyTypeForSingleFieldIdentityType

        public static java.lang.Class getKeyTypeForSingleFieldIdentityType​(java.lang.Class idType)
        Accessor for the type of the single field application-identity key given the single field identity type.
        Parameters:
        idType - Single field identity type
        Returns:
        key type

      • getPersistableIdentityForId

        public static java.lang.String getPersistableIdentityForId​(java.lang.Object id)
        Method to return a persistable form of the identity of a persistable object. This can be used by datastores that don't use foreign keys and want to store the explicit class of the persistable object.
        Parameters:
        id - The id
        Returns:
        String form

      • getObjectFromPersistableIdentity

        public static java.lang.Object getObjectFromPersistableIdentity​(java.lang.String persistableId,
                                                                AbstractClassMetaData cmd,
                                                                ExecutionContext ec)
        Convenience method to find an object given a string form of its identity, and the metadata for the class (or a superclass).
        Parameters:
        persistableId - The persistable id
        cmd - (Root) metadata for the class
        ec - Execution Context
        Returns:
        The object

      • getApplicationIdentityForResultSetRow

        public static java.lang.Object getApplicationIdentityForResultSetRow​(ExecutionContext ec,
                                                                     AbstractClassMetaData cmd,
                                                                     java.lang.Class pcClass,
                                                                     boolean inheritanceCheck,
                                                                     FieldManager resultsFM)
        Method to return the object application identity for a row of the result set. If the class isn't using application identity then returns null
        Parameters:
        ec - Execution Context
        cmd - Metadata for the class
        pcClass - The class required
        inheritanceCheck - Whether need an inheritance check (may be for a subclass)
        resultsFM - FieldManager servicing the results
        Returns:
        The identity (if found) or null (if either not sure of inheritance, or not known).

      • getValueForMemberInId

        public static java.lang.Object getValueForMemberInId​(java.lang.Object id,
                                                     AbstractMemberMetaData pkMmd)
        Convenience method that interrogates a user-supplied object identity and returns the value of a particular member in that id. A user-supplied PK has to provide either public/package/protected fields with the same names as the owning class, or getters for bean properties of the same name as the class members.
        Parameters:
        id - The (user-defined) identity
        pkMmd - Metadata for the member that we require the value for
        Returns:
        The value for this member in the id

      • getObjectFromIdString

        public static java.lang.Object getObjectFromIdString​(java.lang.String idStr,
                                                     AbstractClassMetaData cmd,
                                                     ExecutionContext ec,
                                                     boolean checkInheritance)
        Convenience method to find an object given a string form of its identity, and the metadata for the class (or a superclass). Developers should move to using "persistable identity" and method getObjectFromPersistableIdentity().
        Parameters:
        idStr - The id string
        cmd - Metadata for the class
        ec - Execution Context
        checkInheritance - Whether to check the inheritance level of this object
        Returns:
        The object

      • getObjectFromIdString

        public static java.lang.Object getObjectFromIdString​(java.lang.String idStr,
                                                     AbstractMemberMetaData mmd,
                                                     FieldRole fieldRole,
                                                     ExecutionContext ec,
                                                     boolean checkInheritance)
        Convenience method to find an object given a string form of its identity, and the metadata for the member.
        Parameters:
        idStr - The id string
        mmd - Metadata for the member
        fieldRole - Role of this field (see org.datanucleus.metadata.FieldRole)
        ec - Execution Context
        checkInheritance - Whether to check the inheritance level of this object
        Returns:
        The object