org.jpox.sco
Class Map

java.lang.Object
  extended byjava.util.AbstractMap
      extended byorg.jpox.sco.Map
All Implemented Interfaces:
java.lang.Cloneable, java.util.Map, Queryable, SCO, SCOLazyLoading, SCOMap, java.io.Serializable

public class Map
extends java.util.AbstractMap
implements java.util.Map, SCOMap, SCOLazyLoading, java.lang.Cloneable, Queryable, java.io.Serializable

A mutable second-class Map object. Uses a "delegate" as a local store for the Collection. Uses a "backing store" (SetStore) to represent the datastore. The "delegate" is updated with the "backing store" information at necessary intervals.

Modes of Operation

The user can operate the collection in 2 modes. The cached mode will use an internal cache of the elements (in the "delegate") reading them at the first opportunity and then using the cache thereafter. The non-cached mode will just go direct to the "backing store" each call.

Mutators

When the backing store is present any updates are passed direct to the datastore as well as to the "delegate". If the "backing store" isn't present the changes are made to the "delegate" only.

Accessors

When any accessor method is invoked, it typically checks whether the collection has been loaded from its backing store and does this as necessary. Some methods (size(), containsKey()) just check if everything is loaded and use the delegate if possible, otherwise going direct to the datastore.

Version:
$Revision: 1.48 $
See Also:
Serialized Form

Nested Class Summary
 
Nested classes inherited from class java.util.Map
java.util.Map.Entry
 
Field Summary
protected  MapStore backingStore
          The "backing store"
protected  java.util.Map delegate
          The internal "delegate".
protected  boolean isCacheLoaded
          Status flag whether the collection is loaded into the cache.
protected  boolean useCache
          Whether to use "delegate" caching.
 
Constructor Summary
Map(StateManager ownerSM, java.lang.String fieldName)
          Constructor, using the StateManager of the "owner" and the field name.
 
Method Summary
 void attachCopy(java.lang.Object value)
          Method to return an attached copy of the passed (detached) value.
 void clear()
          Method to clear the Map.
 java.lang.Object clone()
          Creates and returns a copy of this object.
 boolean containsKey(java.lang.Object key)
          Utility to check if a key is contained in the Map.
 boolean containsValue(java.lang.Object value)
          Utility to check if a value is contained in the Map.
 void detach(FetchPlanState state)
          Method to detach this map and its contents.
 java.lang.Object detachCopy(FetchPlanState state)
          Method to return a detached copy of the container.
 java.util.Set entrySet()
          Accessor for the set of entries in the Map.
 boolean equals(java.lang.Object o)
          Method to check the equality of this map, and another.
 java.lang.Object get(java.lang.Object key)
          Accessor for the value stored against a key.
 java.lang.String getFieldName()
          Accessor for the field name.
 java.lang.Object getOwner()
          Accessor for the owner.
 int hashCode()
          Method to generate a hashcode for this Map.
 boolean isEmpty()
          Method to return if the Map is empty.
 java.util.Set keySet()
          Accessor for the set of keys in the Map.
 void load()
          Method to effect the load of the data in the SCO.
protected  void loadFromStore()
          Method to load all elements from the "backing store" where appropriate.
 void makeDirty()
          Utility to mark the object as dirty
 void makeTransient(FetchPlanState state)
          Method to make transient this map and its contents.
 QueryExpression newQueryStatement()
          Method to return a new Query statement for the Map.
 QueryExpression newQueryStatement(java.lang.Class candidate_class)
          Method to return a new Query statement for the Map given the candidate class.
 Query.ResultObjectFactory newResultObjectFactory(QueryExpression stmt, boolean ignoreCache, java.lang.Class resultClass, boolean useFetchPlan)
          Method to return a new result object factory for processing of Query statements.
 java.lang.Object put(java.lang.Object key, java.lang.Object value)
          Method to add a value to the Map.
 void putAll(java.util.Map m)
          Method to add a Map of values to this map.
 java.lang.Object remove(java.lang.Object key)
          Method to remove a value from the Map.
 void runReachability(java.util.Set reachables)
          Method to run reachability on this SCO.
 void setValueFrom(java.lang.Object o, boolean forUpdate)
          Mutator for setting using an object.
 int size()
          Method to return the size of the Map.
 java.lang.String toString()
          Method to return a string form of this Map.
 void unsetOwner()
          Method to unset the owner and field information.
 void updateEmbeddedKey(java.lang.Object key, int fieldNumber, java.lang.Object newValue)
          Method to update an embedded key in this map.
 void updateEmbeddedValue(java.lang.Object value, int fieldNumber, java.lang.Object newValue)
          Method to update an embedded value in this map.
 java.util.Collection values()
          Accessor for the set of values in the Map.
protected  java.lang.Object writeReplace()
          The writeReplace method is called when ObjectOutputStream is preparing to write the object to the stream.
 
Methods inherited from class java.lang.Object
finalize, getClass, notify, notifyAll, wait, wait, wait
 

Field Detail

backingStore

protected MapStore backingStore
The "backing store"


delegate

protected java.util.Map delegate
The internal "delegate".


useCache

protected boolean useCache
Whether to use "delegate" caching.


isCacheLoaded

protected boolean isCacheLoaded
Status flag whether the collection is loaded into the cache.

Constructor Detail

Map

public Map(StateManager ownerSM,
           java.lang.String fieldName)
Constructor, using the StateManager of the "owner" and the field name.

Parameters:
ownerSM - The owner StateManager
fieldName - The name of the field of the SCO.
Method Detail

load

public void load()
Method to effect the load of the data in the SCO. Used when the SCO supports lazy-loading to tell it to load all now.

Specified by:
load in interface SCOLazyLoading

updateEmbeddedKey

public void updateEmbeddedKey(java.lang.Object key,
                              int fieldNumber,
                              java.lang.Object newValue)
Method to update an embedded key in this map.

Specified by:
updateEmbeddedKey in interface SCOMap
Parameters:
key - The key
fieldNumber - Number of field in the key
newValue - New value for this field

updateEmbeddedValue

public void updateEmbeddedValue(java.lang.Object value,
                                int fieldNumber,
                                java.lang.Object newValue)
Method to update an embedded value in this map.

Specified by:
updateEmbeddedValue in interface SCOMap
Parameters:
value - The value
fieldNumber - Number of field in the value
newValue - New value for this field

setValueFrom

public void setValueFrom(java.lang.Object o,
                         boolean forUpdate)
Mutator for setting using an object.

Specified by:
setValueFrom in interface SCO
Parameters:
o - The object to set from
forUpdate - Whether to update the datastore with this value

getFieldName

public java.lang.String getFieldName()
Accessor for the field name.

Specified by:
getFieldName in interface SCO
Returns:
The field name.

getOwner

public java.lang.Object getOwner()
Accessor for the owner.

Specified by:
getOwner in interface SCO
Returns:
The owner.

unsetOwner

public void unsetOwner()
Method to unset the owner and field information.

Specified by:
unsetOwner in interface SCO

makeDirty

public void makeDirty()
Utility to mark the object as dirty


runReachability

public void runReachability(java.util.Set reachables)
Method to run reachability on this SCO.

Specified by:
runReachability in interface SCO
Parameters:
reachables - List of StateManagers reachable so far

makeTransient

public void makeTransient(FetchPlanState state)
Method to make transient this map and its contents.

Specified by:
makeTransient in interface SCO
Parameters:
state - State for the fetchplan process

detach

public void detach(FetchPlanState state)
Method to detach this map and its contents.

Specified by:
detach in interface SCO
Parameters:
state - State for the detachment process

detachCopy

public java.lang.Object detachCopy(FetchPlanState state)
Method to return a detached copy of the container. Recurse sthrough the keys/values so that they are likewise detached.

Specified by:
detachCopy in interface SCO
Parameters:
state - State for detachment process
Returns:
The detached container

attachCopy

public void attachCopy(java.lang.Object value)
Method to return an attached copy of the passed (detached) value. The returned attached copy is a SCO wrapper. Goes through the existing keys/values in the store for this owner field and removes ones no longer present, and adds new keys/values. All keys/values in the (detached) value are attached.

Specified by:
attachCopy in interface SCO
Parameters:
value - The new (collection) value

newQueryStatement

public QueryExpression newQueryStatement()
Method to return a new Query statement for the Map.

Specified by:
newQueryStatement in interface Queryable
Returns:
The Query Statement.

newQueryStatement

public QueryExpression newQueryStatement(java.lang.Class candidate_class)
Method to return a new Query statement for the Map given the candidate class.

Specified by:
newQueryStatement in interface Queryable
Parameters:
candidate_class - the value class.
Returns:
The Query Statement
See Also:
Queryable.newQueryStatement()

newResultObjectFactory

public Query.ResultObjectFactory newResultObjectFactory(QueryExpression stmt,
                                                        boolean ignoreCache,
                                                        java.lang.Class resultClass,
                                                        boolean useFetchPlan)
Method to return a new result object factory for processing of Query statements.

Specified by:
newResultObjectFactory in interface Queryable
Parameters:
stmt - The Query Statement.
ignoreCache - Whether to ignore the cache.
resultClass - Whether to create objects of a particular class
useFetchPlan - whether to use the fetch plan to retrieve fields in the same query
Returns:
The result object factory.

clone

public java.lang.Object clone()
Creates and returns a copy of this object.

Mutable second-class Objects are required to provide a public clone method in order to allow for copying PersistenceCapable objects. In contrast to Object.clone(), this method must not throw a CloneNotSupportedException.

Specified by:
clone in interface SCO
Returns:
Clone of the object

containsKey

public boolean containsKey(java.lang.Object key)
Utility to check if a key is contained in the Map.

Specified by:
containsKey in interface java.util.Map
Parameters:
key - The key to check
Returns:
Whether it is contained

containsValue

public boolean containsValue(java.lang.Object value)
Utility to check if a value is contained in the Map.

Specified by:
containsValue in interface java.util.Map
Parameters:
value - The value to check
Returns:
Whether it is contained

entrySet

public java.util.Set entrySet()
Accessor for the set of entries in the Map.

Specified by:
entrySet in interface java.util.Map
Returns:
Set of entries

equals

public boolean equals(java.lang.Object o)
Method to check the equality of this map, and another.

Specified by:
equals in interface java.util.Map
Parameters:
o - The map to compare against.
Returns:
Whether they are equal.

get

public java.lang.Object get(java.lang.Object key)
Accessor for the value stored against a key.

Specified by:
get in interface java.util.Map
Parameters:
key - The key
Returns:
The value.

hashCode

public int hashCode()
Method to generate a hashcode for this Map.

Specified by:
hashCode in interface java.util.Map
Returns:
The hashcode.

isEmpty

public boolean isEmpty()
Method to return if the Map is empty.

Specified by:
isEmpty in interface java.util.Map
Returns:
Whether it is empty.

keySet

public java.util.Set keySet()
Accessor for the set of keys in the Map.

Specified by:
keySet in interface java.util.Map
Returns:
Set of keys.

size

public int size()
Method to return the size of the Map.

Specified by:
size in interface java.util.Map
Returns:
The size

values

public java.util.Collection values()
Accessor for the set of values in the Map.

Specified by:
values in interface java.util.Map
Returns:
Set of values.

toString

public java.lang.String toString()
Method to return a string form of this Map.

Returns:
String form of this Map.

clear

public void clear()
Method to clear the Map.

Specified by:
clear in interface java.util.Map

put

public java.lang.Object put(java.lang.Object key,
                            java.lang.Object value)
Method to add a value to the Map.

Specified by:
put in interface java.util.Map
Parameters:
key - The key for the value.
value - The value
Returns:
The previous value against this key (if any).

putAll

public void putAll(java.util.Map m)
Method to add a Map of values to this map.

Specified by:
putAll in interface java.util.Map
Parameters:
m - The Map to add

remove

public java.lang.Object remove(java.lang.Object key)
Method to remove a value from the Map.

Specified by:
remove in interface java.util.Map
Parameters:
key - The key for the value.
Returns:
The value removed.

writeReplace

protected java.lang.Object writeReplace()
                                 throws java.io.ObjectStreamException
The writeReplace method is called when ObjectOutputStream is preparing to write the object to the stream. The ObjectOutputStream checks whether the class defines the writeReplace method. If the method is defined, the writeReplace method is called to allow the object to designate its replacement in the stream. The object returned should be either of the same type as the object passed in or an object that when read and resolved will result in an object of a type that is compatible with all references to the object.

Returns:
the replaced object
Throws:
java.io.ObjectStreamException

loadFromStore

protected void loadFromStore()
Method to load all elements from the "backing store" where appropriate.



Copyright © -2007 . All Rights Reserved.