FetchPlan (JDO API 3.1)

```
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

Fields
Modifier and Type	Field and Description
`static String`	`ALL` For use with `addGroup(java.lang.String)`, `removeGroup(java.lang.String)`, and the various `setGroups(java.util.Collection)` calls.
`static 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

All Methods Instance Methods Abstract Methods
Modifier and Type	Method and Description
`FetchPlan`	`addGroup(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.
`Class[]`	`getDetachmentRootClasses()` Get the root classes for DetachAllOnCommit.
`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.
`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(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(Class... rootClasses)` Set the root classes for DetachAllOnCommit.
`FetchPlan`	`setDetachmentRoots(Collection roots)` Set the roots for DetachAllOnCommit.
`FetchPlan`	`setFetchSize(int fetchSize)` Set the fetch size for large result set support.
`FetchPlan`	`setGroup(String fetchGroupName)` Set the active fetch groups to the single named fetch group.
`FetchPlan`	`setGroups(Collection fetchGroupNames)` Set a collection of groups.
`FetchPlan`	`setGroups(String... fetchGroupNames)` Set a collection of groups.
`FetchPlan`	`setMaxFetchDepth(int fetchDepth)` Set the maximum fetch depth when fetching.

- Field Detail
  - DEFAULT
```
static final 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 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(String fetchGroupName)
```
    Add the fetch group to the set of active fetch groups.
    
    Returns:
    
    the FetchPlan
    
    Since:
    
    2.0
  - removeGroup
```
FetchPlan removeGroup(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
```
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(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(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(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(Collection roots)
```
    Set the roots for DetachAllOnCommit.
    
    Parameters:
    
    roots - Collection of the detachment roots.
    
    Since:
    
    2.0
  - getDetachmentRoots
```
Collection getDetachmentRoots()
```
    Get the roots for DetachAllOnCommit.
    
    Returns:
    
    Collection of detachment roots.
    
    Since:
    
    2.0
  - setDetachmentRootClasses
```
FetchPlan setDetachmentRootClasses(Class... rootClasses)
```
    Set the root classes for DetachAllOnCommit.
    
    Parameters:
    
    rootClasses - The root classes.
    
    Since:
    
    2.0
  - getDetachmentRootClasses
```
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.

Interface FetchPlan

Field Summary

Method Summary

Field Detail

DEFAULT

ALL

DETACH_UNLOAD_FIELDS

DETACH_LOAD_FIELDS

FETCH_SIZE_GREEDY

FETCH_SIZE_OPTIMAL

Method Detail

addGroup

removeGroup

clearGroups

getGroups

setGroups

setGroups

setGroup

setMaxFetchDepth

getMaxFetchDepth

setDetachmentRoots

getDetachmentRoots

setDetachmentRootClasses

getDetachmentRootClasses

setFetchSize

getFetchSize

setDetachmentOptions

getDetachmentOptions