javax.jdo
Interface FetchPlan

public interface FetchPlan

Fetch groups are activated using methods on this interface. An instance of this interface can be obtained from PersistenceManager.getFetchPlan(), Extent.getFetchPlan(), and Query.getFetchPlan(). When a Query or Extent is retrieved from a PersistenceManager, its FetchPlan is initialized to the same settings as that of the PersistenceManager. Subsequent modifications of the Query or Extent's FetchPlan are not reflected in the FetchPlan of the PersistenceManager.

Since:

2.0

Version:

2.0

Field Summary

static java.lang.String	ALL For use with addGroup(java.lang.String), removeGroup(java.lang.String), and the various setGroups(java.util.Collection) calls.
static java.lang.String	DEFAULT For use with addGroup(java.lang.String), removeGroup(java.lang.String), and the various setGroups(java.util.Collection) calls.
static int	DETACH_LOAD_FIELDS For use with PersistenceManager.detachCopy(T) and setDetachmentOptions(int).
static int	DETACH_UNLOAD_FIELDS For use with PersistenceManager.detachCopy(T) and setDetachmentOptions(int).
static int	FETCH_SIZE_GREEDY For use with setFetchSize(int).
static int	FETCH_SIZE_OPTIMAL For use with setFetchSize(int).

Method Summary

FetchPlan	addGroup(java.lang.String fetchGroupName) Add the fetch group to the set of active fetch groups.
FetchPlan	clearGroups() Remove all active groups leaving no active fetch group.
int	getDetachmentOptions() Get options used during detachment.
java.lang.Class[]	getDetachmentRootClasses() Get the root classes for DetachAllOnCommit.
java.util.Collection	getDetachmentRoots() Get the roots for DetachAllOnCommit.
int	getFetchSize() Return the fetch size, or FETCH_SIZE_OPTIMAL if not set, or FETCH_SIZE_GREEDY to fetch all.
java.util.Set	getGroups() Return an immutable Set containing the names of all active fetch groups.
int	getMaxFetchDepth() Return the maximum fetch depth used when fetching instances.
FetchPlan	removeGroup(java.lang.String fetchGroupName) Remove the fetch group from the set active fetch groups.
FetchPlan	setDetachmentOptions(int options) Set options to be used during detachment.
FetchPlan	setDetachmentRootClasses(java.lang.Class... rootClasses) Set the root classes for DetachAllOnCommit.
FetchPlan	setDetachmentRoots(java.util.Collection roots) Set the roots for DetachAllOnCommit.
FetchPlan	setFetchSize(int fetchSize) Set the fetch size for large result set support.
FetchPlan	setGroup(java.lang.String fetchGroupName) Set the active fetch groups to the single named fetch group.
FetchPlan	setGroups(java.util.Collection fetchGroupNames) Set a collection of groups.
FetchPlan	setGroups(java.lang.String... fetchGroupNames) Set a collection of groups.
FetchPlan	setMaxFetchDepth(int fetchDepth) Set the maximum fetch depth when fetching.

Field Detail

DEFAULT

static final java.lang.String DEFAULT

For use with addGroup(java.lang.String), removeGroup(java.lang.String), and the various setGroups(java.util.Collection) calls. Value: default.

Since:

2.0

See Also:

Constant Field Values

ALL

static final java.lang.String ALL

For use with addGroup(java.lang.String), removeGroup(java.lang.String), and the various setGroups(java.util.Collection) calls. Value: all.

Since:

2.0

See Also:

Constant Field Values

DETACH_UNLOAD_FIELDS

static final int DETACH_UNLOAD_FIELDS

For use with PersistenceManager.detachCopy(T) and setDetachmentOptions(int). Specifies that fields that are loaded but not in the current fetch plan should be unloaded prior to detachment.

Since:

2.0

See Also:

Constant Field Values

DETACH_LOAD_FIELDS

static final int DETACH_LOAD_FIELDS

For use with PersistenceManager.detachCopy(T) and setDetachmentOptions(int). Specifies that fields that are not loaded but are in the current fetch plan should be loaded prior to detachment.

Since:

2.0

See Also:

Constant Field Values

FETCH_SIZE_GREEDY

static final int FETCH_SIZE_GREEDY

For use with setFetchSize(int). Value: -1.

Since:

2.0

See Also:

Constant Field Values

FETCH_SIZE_OPTIMAL

static final int FETCH_SIZE_OPTIMAL

For use with setFetchSize(int). Value: 0.

Since:

2.0

See Also:

Constant Field Values

Method Detail

addGroup

FetchPlan addGroup(java.lang.String fetchGroupName)

Add the fetch group to the set of active fetch groups.

Returns:

the FetchPlan

Since:

2.0

removeGroup

FetchPlan removeGroup(java.lang.String fetchGroupName)

Remove the fetch group from the set active fetch groups.

Returns:

the FetchPlan

Since:

2.0

clearGroups

FetchPlan clearGroups()

Remove all active groups leaving no active fetch group.

Returns:

the FetchPlan

Since:

2.0

getGroups

java.util.Set getGroups()

Return an immutable Set containing the names of all active fetch groups. The Set is a copy of the currently active groups and will not change based on subsequent changes to the groups.

Returns:

an immutable Set containing the names of all currently active fetch groups

Since:

2.0

setGroups

FetchPlan setGroups(java.util.Collection fetchGroupNames)

Set a collection of groups.

Parameters:

fetchGroupNames - a collection of names of fetch groups

Returns:

the FetchPlan

Since:

2.0

setGroups

FetchPlan setGroups(java.lang.String... fetchGroupNames)

Set a collection of groups.

Parameters:

fetchGroupNames - a String array of names of fetch groups

Returns:

the FetchPlan

Since:

2.0

setGroup

FetchPlan setGroup(java.lang.String fetchGroupName)

Set the active fetch groups to the single named fetch group.

Parameters:

fetchGroupName - the single fetch group

Returns:

the FetchPlan

Since:

2.0

setMaxFetchDepth

FetchPlan setMaxFetchDepth(int fetchDepth)

Set the maximum fetch depth when fetching. A value of 0 has no meaning and will throw a JDOUserException. A value of -1 means that no limit is placed on fetching. A positive integer will result in that number of references from the initial object to be fetched.

Parameters:

fetchDepth - the depth

Returns:

the FetchPlan

Since:

2.0

getMaxFetchDepth

int getMaxFetchDepth()

Return the maximum fetch depth used when fetching instances.

Returns:

the maximum fetch depth

Since:

2.0

setDetachmentRoots

FetchPlan setDetachmentRoots(java.util.Collection roots)

Set the roots for DetachAllOnCommit.

Parameters:

roots - Collection of the detachment roots.

Since:

2.0

getDetachmentRoots

java.util.Collection getDetachmentRoots()

Get the roots for DetachAllOnCommit.

Returns:

Collection of detachment roots.

Since:

2.0

setDetachmentRootClasses

FetchPlan setDetachmentRootClasses(java.lang.Class... rootClasses)

Set the root classes for DetachAllOnCommit.

Parameters:

rootClasses - The root classes.

Since:

2.0

getDetachmentRootClasses

java.lang.Class[] getDetachmentRootClasses()

Get the root classes for DetachAllOnCommit.

Returns:

The detachment root classes

Since:

2.0

setFetchSize

FetchPlan setFetchSize(int fetchSize)

Set the fetch size for large result set support. Use FETCH_SIZE_OPTIMAL to unset, and FETCH_SIZE_GREEDY to force loading of everything.

Parameters:

fetchSize - the fetch size

Returns:

the FetchPlan

Since:

2.0

getFetchSize

int getFetchSize()

Return the fetch size, or FETCH_SIZE_OPTIMAL if not set, or FETCH_SIZE_GREEDY to fetch all.

Returns:

the fetch size

Since:

2.0

setDetachmentOptions

FetchPlan setDetachmentOptions(int options)

Set options to be used during detachment. Options are DETACH_LOAD_FIELDS and DETACH_UNLOAD_FIELDS.

getDetachmentOptions

int getDetachmentOptions()

Get options used during detachment.