Module org.datanucleus
Package org.datanucleus

Class FetchGroup<T>

  • Type Parameters:
    T - Class that this FetchGroup is for
    All Implemented Interfaces:
    Serializable
    public class FetchGroup<T>
extends Object
implements Serializable
    Group of fields for fetching, to be used by a FetchPlan. Defined at runtime, via the API (aka dynamic fetch group). Shared by FetchPlan's, so can be used by multiple threads.
    See Also:
    Serialized Form

    • Constructor Detail

      • FetchGroup

        public FetchGroup​(NucleusContext nucleusCtx,
                  String name,
                  Class<T> cls)
        Constructor.
        Parameters:
        nucleusCtx - Context
        name - Name of the group
        cls - The class

      • FetchGroup

        public FetchGroup​(FetchGroup<T> grp)
        Constructor to take a copy of the supplied group, but modifiable.
        Parameters:
        grp - The existing group

    • Method Detail

      • getName

        public String getName()
        Accessor for the group name.
        Returns:
        Name of the group

      • getType

        public Class<T> getType()
        Accessor for the class that this group is for.
        Returns:
        the class

      • setPostLoad

        public void setPostLoad​(boolean postLoad)
        Mutator for whether the postLoad callback should be called on loading this fetch group.
        Parameters:
        postLoad - Whether the postLoad callback should be called.

      • getPostLoad

        public boolean getPostLoad()
        Accessor for whether to call postLoad when this group is loaded.
        Returns:
        Whether to call postLoad

      • getRecursionDepth

        public int getRecursionDepth​(String memberName)
        Accessor for the recursion depth for the specified field/property.
        Parameters:
        memberName - Name of field/property
        Returns:
        The recursion depth

      • setRecursionDepth

        public FetchGroup setRecursionDepth​(String memberName,
                                    int recursionDepth)
        Method to set the recursion depth for the specified field/property.
        Parameters:
        memberName - Name of field/property
        recursionDepth - Recursion depth
        Returns:
        The fetch group

      • setUnmodifiable

        public FetchGroup setUnmodifiable()
        Method to make the group unmodifiable. Once unmodifiable it cannot be made modifiable again.
        Returns:
        This group

      • isUnmodifiable

        public boolean isUnmodifiable()
        Accessor for modifiability status of this group.
        Returns:
        Whether it is no longer modifiable

      • addCategory

        public FetchGroup addCategory​(String categoryName)
        Convenience method to add the members for the specified category. Supports the categories defined in the JDO spec.
        Parameters:
        categoryName - Name of the category
        Returns:
        This group

      • removeCategory

        public FetchGroup removeCategory​(String categoryName)
        Convenience method to remove the members for the specified category. Supports the categories defined in the JDO spec.
        Parameters:
        categoryName - Name of the category
        Returns:
        This group

      • getMembers

        public Set<String> getMembers()
        Accessor for the members that are in this fetch group.
        Returns:
        Set of member names.

      • addMember

        public FetchGroup addMember​(String memberName)
        Method to add a field of the class to the fetch group.
        Parameters:
        memberName - Name of the field/property
        Returns:
        This FetchGroup
        Throws:
        NucleusUserException - if the field/property doesn't exist for this class

      • removeMember

        public FetchGroup removeMember​(String memberName)
        Method to remove a field of the class from the fetch group.
        Parameters:
        memberName - Name of the field/property
        Returns:
        This FetchGroup
        Throws:
        NucleusUserException - if the field/property doesn't exist for this class

      • registerListener

        public void registerListener​(FetchPlan plan)
        Method to register a listener for changes to this FetchGroup.
        Parameters:
        plan - The FetchPlan that is listening

      • deregisterListener

        public void deregisterListener​(FetchPlan plan)
        Method to deregister a listener for changes to this FetchGroup.
        Parameters:
        plan - The FetchPlan that is no longer listening

      • disconnectFromListeners

        public void disconnectFromListeners()
        Method to disconnect this fetch group from all listeners since the group is removed from use.

      • hashCode

        public int hashCode()
        Overrides:
        hashCode in class Object