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	FETCH_SIZE_GREEDY For use with setFetchSize(int).
static int	FETCH_SIZE_OPTIMAL For use with setFetchSize(int).
static java.lang.String	NONE For use with addGroup(java.lang.String), removeGroup(java.lang.String), and the various setGroups(java.util.Collection) calls.
static java.lang.String	VALUES For use with addGroup(java.lang.String), removeGroup(java.lang.String), and the various setGroups(java.util.Collection) calls.

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	getFetchSize() Return the fetch size, or FETCH_SIZE_OPTIMAL if not set, or FETCH_SIZE_GREEDY to fetch all.
java.util.Collection	getGroups() Return the names of all active fetch groups.
FetchPlan	removeGroup(java.lang.String fetchGroupName) Remove the fetch group from the set active fetch groups.
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.

Field Detail

DEFAULT

public 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

public 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

VALUES

public static final java.lang.String VALUES

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

Since:

2.0

See Also:

Constant Field Values

NONE

public static final java.lang.String NONE

For use with addGroup(java.lang.String), removeGroup(java.lang.String), and the various setGroups(java.util.Collection) calls. Value: none. ### this is not mentioned in 12.7.2. It is referred to in 12.7's text.

Since:

2.0

See Also:

Constant Field Values

FETCH_SIZE_GREEDY

public static final int FETCH_SIZE_GREEDY

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

Since:

2.0

See Also:

Constant Field Values

FETCH_SIZE_OPTIMAL

public static final int FETCH_SIZE_OPTIMAL

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

Since:

2.0

See Also:

Constant Field Values

Method Detail

addGroup

public FetchPlan addGroup(java.lang.String fetchGroupName)

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

Returns:

the FetchPlan

Since:

2.0

removeGroup

public FetchPlan removeGroup(java.lang.String fetchGroupName)

Remove the fetch group from the set active fetch groups.

Returns:

the FetchPlan

Since:

2.0

clearGroups

public FetchPlan clearGroups()

Remove all active groups leaving no active fetch group.

Returns:

the FetchPlan

Since:

2.0

getGroups

public java.util.Collection getGroups()

Return the names of all active fetch groups.

Returns:

the names of active fetch groups

Since:

2.0

setGroups

public 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

public 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

public 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

setFetchSize

public 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

public 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