wt.fc.collections
Class CollectionsHelper

java.lang.Object
  wt.fc.collections.CollectionsHelper

public final class CollectionsHelper
extends Object

Provides utility methods for dealing with WTCollections.

Supported API: true

Extendable: false

Method Summary

static List	getExcludedClasses(WTCollection collection, Class base_class) Get the list of known subclasses of the given base_class that do not have instances in the given collection.
static WTSet	getNonPersistedSubSet(WTCollection collection, boolean connect) Get a sub set of the objects in the given collection that are not persisted.
static WTSet	getPersistedSubSet(WTCollection collection, boolean connect) Get a sub set of the objects in the given collection that are persisted.
static void	inflate(WTCollection collection) Inflate all elements in the collection that do not have an in-memory copy of their Persistable.
static void	inflate(WTCollection collection, RefreshSpec spec) Inflate all elements in the collection that do not have an in-memory copy of their Persistable.
static void	inflate(WTKeyedMap map) Inflate all elements in the map that do not have an in-memory copy of their Persistable.
static void	inflate(WTKeyedMap map, RefreshSpec spec) Inflate all elements in the map that do not have an in-memory copy of their Persistable, with access control disabled..
static boolean	isInflated(WTCollection collection) Determine if the given collection contains inflated objects.
static WTKeyedMap	singletonWTKeyedMap(Object key, Object value) Returns an immutable WTKeyedMap, mapping only the specified key to the specified value.
static WTList	singletonWTList(Object o) Returns an immutable WTList containing only the specified object.
static WTSet	singletonWTSet(Object o) Returns an immutable WTSet containing only the specified object.
static WTValuedMap	singletonWTValuedMap(Object key, Object value) Returns an immutable WTValuedMap, mapping only the specified key to the specified value.
static WTCollection	synchronizedWTCollection(WTCollection collection) Supported API: true
static WTKeyedMap	synchronizedWTKeyedMap(WTKeyedMap map) Supported API: true
static WTList	synchronizedWTList(WTList list) Supported API: true
static WTSet	synchronizedWTSet(WTSet set) Supported API: true
static WTValuedMap	synchronizedWTValuedMap(WTValuedMap map) Supported API: true
static WTCollection	unmodifiableWTCollection(WTCollection collection) Supported API: true
static WTKeyedMap	unmodifiableWTKeyedMap(WTKeyedMap map) Supported API: true
static WTList	unmodifiableWTList(WTList list) Supported API: true
static WTSet	unmodifiableWTSet(WTSet set) Supported API: true
static WTValuedMap	unmodifiableWTValuedMap(WTValuedMap map) Supported API: true
static void	validate(WTCollection collection, Class filter) Ensures that all the objects in the given collection are instances of the given filter class.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Method Detail

getExcludedClasses

public static List getExcludedClasses(WTCollection collection,
                                      Class base_class)
                               throws WTException

Get the list of known subclasses of the given base_class that do not have instances in the given collection. This list can then be used to set the excluded descendants on a TableExpression in order to optimize the number of tables a database query needs to hit.

Supported API: true

Parameters:

collection -

base_class -

Returns:

A list of Classes

Throws:

WTException

See Also:

wt.query.AbstractTableExpression#setExcludedDescendants(List)

getNonPersistedSubSet

public static WTSet getNonPersistedSubSet(WTCollection collection,
                                          boolean connect)

Get a sub set of the objects in the given collection that are not persisted. The resulting WTSet is connected to the collection if connect is true. The resulting WTSet is never backed by the collection however -- so additions and removals to one are not reflected in the other.

Supported API: true

Parameters:

collection -

connect -

Returns:

A WTSet containing the non-persisted Persistables in this collection, or EMPTY_SET if there are none.

See Also:

getPersistedSubSet(wt.fc.collections.WTCollection, boolean)

getPersistedSubSet

public static WTSet getPersistedSubSet(WTCollection collection,
                                       boolean connect)

Get a sub set of the objects in the given collection that are persisted. The resulting WTSet is connected to the collection if connect is true. The resulting WTSet is never backed by the collection however -- so additions and removals to one are not reflected in the other.

Supported API: true

Parameters:

collection -

connect -

Returns:

A WTSet containing the persisted Persistables in this collection, or EMPTY_SET if there are none.

See Also:

getNonPersistedSubSet(wt.fc.collections.WTCollection, boolean)

inflate

public static void inflate(WTCollection collection)
                    throws WTException

Inflate all elements in the collection that do not have an in-memory copy of their Persistable. Persistables that are already in the collection are not refreshed.

Supported API: true

Parameters:

collection -

Throws:

WTException

inflate

public static void inflate(WTKeyedMap map)
                    throws WTException

Inflate all elements in the map that do not have an in-memory copy of their Persistable. Persistables that are already in the map are not refreshed. If the map is an instanceof WTValuedMap, then both the keys and the values are inflated.

Supported API: true

Parameters:

map -

Throws:

WTException

inflate

public static void inflate(WTCollection collection,
                           RefreshSpec spec)
                    throws WTException

Inflate all elements in the collection that do not have an in-memory copy of their Persistable. Use the given RefreshSpec to inflate the elements.

Supported API: true

Parameters:

collection -

spec -

Throws:

WTException

inflate

public static void inflate(WTKeyedMap map,
                           RefreshSpec spec)
                    throws WTException

Inflate all elements in the map that do not have an in-memory copy of their Persistable, with access control disabled.. Persistables that are already in the map are not refreshed. If the map is an instanceof WTValuedMap, then both the keys and the values are inflated. se the given RefreshSpec to inflate the elements.

Supported API: true

Parameters:

map -

spec -

Throws:

WTException

isInflated

public static boolean isInflated(WTCollection collection)

Determine if the given collection contains inflated objects. If the collection doesn't contain inflated objects, then calls to persistable-based APIs will require a trip to the server and possibly the database.

Supported API: true

Parameters:

collection -

Returns:

true if this collection doesn't need to be inflated

synchronizedWTCollection

public static WTCollection synchronizedWTCollection(WTCollection collection)

Supported API: true

Parameters:

collection -

Returns:

WTCollection

synchronizedWTKeyedMap

public static WTKeyedMap synchronizedWTKeyedMap(WTKeyedMap map)

Supported API: true

Parameters:

map -

Returns:

WTKeyedMap

synchronizedWTList

public static WTList synchronizedWTList(WTList list)

Supported API: true

Parameters:

list -

Returns:

WTList

synchronizedWTSet

public static WTSet synchronizedWTSet(WTSet set)

Supported API: true

Parameters:

set -

Returns:

WTSet

synchronizedWTValuedMap

public static WTValuedMap synchronizedWTValuedMap(WTValuedMap map)

Supported API: true

Parameters:

map -

Returns:

WTValuedMap

unmodifiableWTCollection

public static WTCollection unmodifiableWTCollection(WTCollection collection)

Supported API: true

Parameters:

collection -

Returns:

WTCollection

unmodifiableWTKeyedMap

public static WTKeyedMap unmodifiableWTKeyedMap(WTKeyedMap map)

Supported API: true

Parameters:

map -

Returns:

WTKeyedMap

unmodifiableWTList

public static WTList unmodifiableWTList(WTList list)

Supported API: true

Parameters:

list -

Returns:

WTList

unmodifiableWTSet

public static WTSet unmodifiableWTSet(WTSet set)

Supported API: true

Parameters:

set -

Returns:

WTSet

unmodifiableWTValuedMap

public static WTValuedMap unmodifiableWTValuedMap(WTValuedMap map)

Supported API: true

Parameters:

map -

Returns:

WTValuedMap

validate

public static void validate(WTCollection collection,
                            Class filter)

Ensures that all the objects in the given collection are instances of the given filter class.

Supported API: true

Parameters:

collection -

filter -

Throws:

ClassCastException - If the filter is not assignable from the class of at least one of the objects in the collection

singletonWTSet

public static WTSet singletonWTSet(Object o)

Returns an immutable WTSet containing only the specified object.

Supported API: true

Parameters:

o - The sole object to be stored in the returned WTSet.

Returns:

An immutable WTSet containing only the specified object.

singletonWTList

public static WTList singletonWTList(Object o)

Returns an immutable WTList containing only the specified object.

Supported API: true

Parameters:

o - The sole object to be stored in the returned WTList.

Returns:

An immutable WTList containing only the specified object.

singletonWTKeyedMap

public static WTKeyedMap singletonWTKeyedMap(Object key,
                                             Object value)

Returns an immutable WTKeyedMap, mapping only the specified key to the specified value.

Supported API: true

Parameters:

key - The sole key to be stored in the returned WTKeyedMap.

value - The value to which the returned WTKeyedMap maps key.

Returns:

An immutable WTKeyedMap containing only the specified key-value mapping.

singletonWTValuedMap

public static WTValuedMap singletonWTValuedMap(Object key,
                                               Object value)

Returns an immutable WTValuedMap, mapping only the specified key to the specified value.

Supported API: true

Parameters:

key - The sole key to be stored in the returned WTValuedMap.

value - The value to which the returned WTValuedMap maps key.

Returns:

An immutable WTValuedMap containing only the specified key-value mapping.