org.apache.openjpa.kernel
Class FetchConfigurationImpl

java.lang.Object
  org.apache.openjpa.kernel.FetchConfigurationImpl

All Implemented Interfaces:

Serializable, Cloneable, FetchConfiguration, LockLevels, QueryFlushModes

Direct Known Subclasses:

JDBCFetchConfigurationImpl

public class FetchConfigurationImpl
extends Object
implements FetchConfiguration, Cloneable

Allows configuration and optimization of how objects are loaded from the data store.

Since:

0.3.0

Author:

Abe White, Pinaki Poddar

See Also:

Serialized Form

Nested Class Summary

protected static class

FetchConfigurationImpl.ConfigurationState Configurable state shared throughout a traversal chain.

Field Summary

Fields inherited from interface org.apache.openjpa.kernel.FetchConfiguration

DEFAULT, FETCH_LOAD, FETCH_NONE, FETCH_REF

Fields inherited from interface org.apache.openjpa.kernel.LockLevels

LOCK_NONE, LOCK_READ, LOCK_WRITE

Fields inherited from interface org.apache.openjpa.kernel.QueryFlushModes

FLUSH_FALSE, FLUSH_TRUE, FLUSH_WITH_CONNECTION

Constructor Summary

	FetchConfigurationImpl()
protected	FetchConfigurationImpl(FetchConfigurationImpl.ConfigurationState state)

Method Summary

FetchConfiguration	addFetchGroup(String name) Adds group to the set of fetch group names to use when loading objects.
FetchConfiguration	addFetchGroups(Collection groups) Adds groups to the set of fetch group names to use when loading objects.
FetchConfiguration	addField(String field) Adds field to the set of fully-qualified field names to use when loading objects.
FetchConfiguration	addFields(Collection fields) Adds fields to the set of fully-qualified field names to use when loading objects.
FetchConfiguration	clearFetchGroups() Clears the set of fetch group names to use when loading data.
FetchConfiguration	clearFields() Clears the set of field names to use when loading data.
Object	clone() Clone this instance.
void	copy(FetchConfiguration fetch) Copy the state from the given fetch configuration to this one.
StoreContext	getContext() Return the context assiciated with this configuration; may be null if it has not been set or this object has been serialized.
int	getFetchBatchSize() Return the fetch batch size for large result set support.
Set	getFetchGroups() Returns immutable set of names of the fetch groups that this component will use when loading objects.
Set	getFields() Returns the set of fully-qualified field names that this component will use when loading objects.
int	getFlushBeforeQueries() The query automatic flush configuration.
Object	getHint(String name) Returns the hint for the specific key, or null if the hint is not specified.
int	getLockTimeout() The number of milliseconds to wait for an object lock, or -1 for no limit.
int	getMaxFetchDepth() Return the maximum depth of fetched instance graph.
boolean	getQueryCacheEnabled() Return whether or not query caching is enabled.
int	getReadLockLevel() The lock level to use for locking loaded objects.
Set	getRootClasses() Root classes for recursive operations.
Set	getRootInstances() Root instances for recursive operations.
int	getWriteLockLevel() The lock level to use for locking dirtied objects.
boolean	hasFetchGroup(String group) Return true if the given fetch group has been added.
boolean	hasField(String field) Return true if the given fully-qualified field has been added.
void	lock() Synchronize on internal lock if multithreaded is true.
protected FetchConfigurationImpl	newInstance(FetchConfigurationImpl.ConfigurationState state) Return a new hollow instance.
ResultList	newResultList(ResultObjectProvider rop) Return a new result list for the current fetch configuration.
FetchConfiguration	removeFetchGroup(String group) Remove the given fetch group.
FetchConfiguration	removeFetchGroups(Collection groups) Removes groups from the set of fetch group names to use when loading objects.
FetchConfiguration	removeField(String field) Remove the given fully-qualified field.
FetchConfiguration	removeFields(Collection fields) Removes fields from the set of fully-qualified field names to use when loading objects.
int	requiresFetch(FieldMetaData fm) Affirms if the given field requires to be fetched in the context of current fetch operation.
boolean	requiresLoad() Return false if we know that the object being fetched with this configuration does not require a load, because this configuration came from a traversal of a FetchConfiguration.FETCH_REF field.
FetchConfiguration	resetFetchGroups() Resets the set of fetch groups to the list in the global configuration.
void	setContext(StoreContext ctx) Called automatically by the system to associate the fetch configuration with a context before use.
FetchConfiguration	setFetchBatchSize(int fetchBatchSize) Set the fetch batch size for large result set support.
FetchConfiguration	setFlushBeforeQueries(int flush) The query automatic flush configuration.
void	setHint(String name, Object value) Sets an arbitrary query hint that may be utilized during execution.
FetchConfiguration	setLockTimeout(int timeout) The number of milliseconds to wait for an object lock, or -1 for no limit.
FetchConfiguration	setMaxFetchDepth(int depth) Set the maximum depth of the fetched instance graph.
FetchConfiguration	setQueryCacheEnabled(boolean cache) Control whether or not query caching is enabled.
FetchConfiguration	setReadLockLevel(int level) The lock level to use for locking loaded objects.
FetchConfiguration	setRootClasses(Collection classes) Root classes for recursive operations.
FetchConfiguration	setRootInstances(Collection instances) Root instances for recursive operations.
FetchConfiguration	setWriteLockLevel(int level) The lock level to use for locking dirtied objects.
String	toString()
FetchConfiguration	traverse(FieldMetaData fm) Traverse the given field to generate (possibly) a new configuration state.
void	unlock() Release internal lock if multithreaded is true.

Methods inherited from class java.lang.Object

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

Constructor Detail

FetchConfigurationImpl

public FetchConfigurationImpl()

FetchConfigurationImpl

protected FetchConfigurationImpl(FetchConfigurationImpl.ConfigurationState state)

Method Detail

getContext

public StoreContext getContext()

Description copied from interface: FetchConfiguration

Return the context assiciated with this configuration; may be null if it has not been set or this object has been serialized.

Specified by:

getContext in interface FetchConfiguration

setContext

public void setContext(StoreContext ctx)

Description copied from interface: FetchConfiguration

Called automatically by the system to associate the fetch configuration with a context before use. The fetch configuration properties should be synchronized with the context's configuration object. Subclasses for specific back ends cannot rely on the context's configuration implementing their back end's configuration sub-interface.

Specified by:

setContext in interface FetchConfiguration

clone

public Object clone()

Clone this instance.

Specified by:

clone in interface FetchConfiguration

Overrides:

clone in class Object

newInstance

protected FetchConfigurationImpl newInstance(FetchConfigurationImpl.ConfigurationState state)

Return a new hollow instance.

copy

public void copy(FetchConfiguration fetch)

Description copied from interface: FetchConfiguration

Copy the state from the given fetch configuration to this one.

Specified by:

copy in interface FetchConfiguration

getFetchBatchSize

public int getFetchBatchSize()

Description copied from interface: FetchConfiguration

Return the fetch batch size for large result set support. Defaults to the openjpa.FetchBatchSize setting. Note that this property will be ignored under some data stores.

Specified by:

getFetchBatchSize in interface FetchConfiguration

setFetchBatchSize

public FetchConfiguration setFetchBatchSize(int fetchBatchSize)

Description copied from interface: FetchConfiguration

Set the fetch batch size for large result set support. Defaults to the openjpa.FetchBatchSize setting. Note that this property will be ignored under some data stores.

Specified by:

setFetchBatchSize in interface FetchConfiguration

getMaxFetchDepth

public int getMaxFetchDepth()

Description copied from interface: FetchConfiguration

Return the maximum depth of fetched instance graph. Defaults to 1

Specified by:

getMaxFetchDepth in interface FetchConfiguration

setMaxFetchDepth

public FetchConfiguration setMaxFetchDepth(int depth)

Description copied from interface: FetchConfiguration

Set the maximum depth of the fetched instance graph.

Specified by:

setMaxFetchDepth in interface FetchConfiguration

Parameters:

depth - denotes limiting length of traversal path from a root instance. -1 implies no limit. 0 is not permissible.

getQueryCacheEnabled

public boolean getQueryCacheEnabled()

Description copied from interface: FetchConfiguration

Return whether or not query caching is enabled. If this returns true but the datacache plugin is not installed, caching will not be enabled. If this returns false, query caching will not be used even if the datacache plugin is installed.

Specified by:

getQueryCacheEnabled in interface FetchConfiguration

setQueryCacheEnabled

public FetchConfiguration setQueryCacheEnabled(boolean cache)

Description copied from interface: FetchConfiguration

Control whether or not query caching is enabled. This has no effect if the datacache plugin is not installed, or if the query cache size is set to zero.

Specified by:

setQueryCacheEnabled in interface FetchConfiguration

getFlushBeforeQueries

public int getFlushBeforeQueries()

Description copied from interface: FetchConfiguration

The query automatic flush configuration.

Specified by:

getFlushBeforeQueries in interface FetchConfiguration

setFlushBeforeQueries

public FetchConfiguration setFlushBeforeQueries(int flush)

Description copied from interface: FetchConfiguration

The query automatic flush configuration.

Specified by:

setFlushBeforeQueries in interface FetchConfiguration

getFetchGroups

public Set getFetchGroups()

Description copied from interface: FetchConfiguration

Returns immutable set of names of the fetch groups that this component will use when loading objects. Defaults to the openjpa.FetchGroups setting. This set is not thread safe.

Specified by:

getFetchGroups in interface FetchConfiguration

hasFetchGroup

public boolean hasFetchGroup(String group)

Description copied from interface: FetchConfiguration

Return true if the given fetch group has been added.

Specified by:

hasFetchGroup in interface FetchConfiguration

addFetchGroup

public FetchConfiguration addFetchGroup(String name)

Description copied from interface: FetchConfiguration

Adds group to the set of fetch group names to use when loading objects.

Specified by:

addFetchGroup in interface FetchConfiguration

addFetchGroups

public FetchConfiguration addFetchGroups(Collection groups)

Description copied from interface: FetchConfiguration

Adds groups to the set of fetch group names to use when loading objects.

Specified by:

addFetchGroups in interface FetchConfiguration

removeFetchGroup

public FetchConfiguration removeFetchGroup(String group)

Description copied from interface: FetchConfiguration

Remove the given fetch group.

Specified by:

removeFetchGroup in interface FetchConfiguration

removeFetchGroups

public FetchConfiguration removeFetchGroups(Collection groups)

Description copied from interface: FetchConfiguration

Removes groups from the set of fetch group names to use when loading objects.

Specified by:

removeFetchGroups in interface FetchConfiguration

clearFetchGroups

public FetchConfiguration clearFetchGroups()

Description copied from interface: FetchConfiguration

Clears the set of fetch group names to use when loading data. After this operation is invoked, only those fields in the default fetch group (and any requested field) will be loaded when loading an object.

Specified by:

clearFetchGroups in interface FetchConfiguration

resetFetchGroups

public FetchConfiguration resetFetchGroups()

Description copied from interface: FetchConfiguration

Resets the set of fetch groups to the list in the global configuration.

Specified by:

resetFetchGroups in interface FetchConfiguration

getFields

public Set getFields()

Description copied from interface: FetchConfiguration

Returns the set of fully-qualified field names that this component will use when loading objects. Defaults to the empty set. This set is not thread safe.

Specified by:

getFields in interface FetchConfiguration

hasField

public boolean hasField(String field)

Description copied from interface: FetchConfiguration

Return true if the given fully-qualified field has been added.

Specified by:

hasField in interface FetchConfiguration

addField

public FetchConfiguration addField(String field)

Description copied from interface: FetchConfiguration

Adds field to the set of fully-qualified field names to use when loading objects.

Specified by:

addField in interface FetchConfiguration

addFields

public FetchConfiguration addFields(Collection fields)

Description copied from interface: FetchConfiguration

Adds fields to the set of fully-qualified field names to use when loading objects.

Specified by:

addFields in interface FetchConfiguration

removeField

public FetchConfiguration removeField(String field)

Description copied from interface: FetchConfiguration

Remove the given fully-qualified field.

Specified by:

removeField in interface FetchConfiguration

removeFields

public FetchConfiguration removeFields(Collection fields)

Description copied from interface: FetchConfiguration

Removes fields from the set of fully-qualified field names to use when loading objects.

Specified by:

removeFields in interface FetchConfiguration

clearFields

public FetchConfiguration clearFields()

Description copied from interface: FetchConfiguration

Clears the set of field names to use when loading data. After this operation is invoked, only those fields in the configured fetch groups will be loaded when loading an object.

Specified by:

clearFields in interface FetchConfiguration

getLockTimeout

public int getLockTimeout()

Description copied from interface: FetchConfiguration

The number of milliseconds to wait for an object lock, or -1 for no limit.

Specified by:

getLockTimeout in interface FetchConfiguration

setLockTimeout

public FetchConfiguration setLockTimeout(int timeout)

Description copied from interface: FetchConfiguration

The number of milliseconds to wait for an object lock, or -1 for no limit.

Specified by:

setLockTimeout in interface FetchConfiguration

getReadLockLevel

public int getReadLockLevel()

Description copied from interface: FetchConfiguration

The lock level to use for locking loaded objects.

Specified by:

getReadLockLevel in interface FetchConfiguration

setReadLockLevel

public FetchConfiguration setReadLockLevel(int level)

Description copied from interface: FetchConfiguration

The lock level to use for locking loaded objects.

Specified by:

setReadLockLevel in interface FetchConfiguration

getWriteLockLevel

public int getWriteLockLevel()

Description copied from interface: FetchConfiguration

The lock level to use for locking dirtied objects.

Specified by:

getWriteLockLevel in interface FetchConfiguration

setWriteLockLevel

public FetchConfiguration setWriteLockLevel(int level)

Description copied from interface: FetchConfiguration

The lock level to use for locking dirtied objects.

Specified by:

setWriteLockLevel in interface FetchConfiguration

newResultList

public ResultList newResultList(ResultObjectProvider rop)

Description copied from interface: FetchConfiguration

Return a new result list for the current fetch configuration.

Specified by:

newResultList in interface FetchConfiguration

setHint

public void setHint(String name,
                    Object value)

Description copied from interface: FetchConfiguration

Sets an arbitrary query hint that may be utilized during execution. The hint may be datastore-specific.

Specified by:

setHint in interface FetchConfiguration

Parameters:

name - the name of the hint

value - the value of the hint

getHint

public Object getHint(String name)

Description copied from interface: FetchConfiguration

Returns the hint for the specific key, or null if the hint is not specified.

Specified by:

getHint in interface FetchConfiguration

Parameters:

name - the hint name

getRootClasses

public Set getRootClasses()

Description copied from interface: FetchConfiguration

Root classes for recursive operations. This set is not thread safe.

Specified by:

getRootClasses in interface FetchConfiguration

setRootClasses

public FetchConfiguration setRootClasses(Collection classes)

Description copied from interface: FetchConfiguration

Root classes for recursive operations.

Specified by:

setRootClasses in interface FetchConfiguration

getRootInstances

public Set getRootInstances()

Description copied from interface: FetchConfiguration

Root instances for recursive operations. This set is not thread safe.

Specified by:

getRootInstances in interface FetchConfiguration

setRootInstances

public FetchConfiguration setRootInstances(Collection instances)

Description copied from interface: FetchConfiguration

Root instances for recursive operations.

Specified by:

setRootInstances in interface FetchConfiguration

lock

public void lock()

Description copied from interface: FetchConfiguration

Synchronize on internal lock if multithreaded is true.

Specified by:

lock in interface FetchConfiguration

unlock

public void unlock()

Description copied from interface: FetchConfiguration

Release internal lock if multithreaded is true.

Specified by:

unlock in interface FetchConfiguration

requiresFetch

public int requiresFetch(FieldMetaData fm)

Description copied from interface: FetchConfiguration

Affirms if the given field requires to be fetched in the context of current fetch operation. Returns one of FetchConfiguration.FETCH_NONE, FetchConfiguration.FETCH_LOAD, FETCH_REF.

Specified by:

requiresFetch in interface FetchConfiguration

requiresLoad

public boolean requiresLoad()

Description copied from interface: FetchConfiguration

Return false if we know that the object being fetched with this configuration does not require a load, because this configuration came from a traversal of a FetchConfiguration.FETCH_REF field.

Specified by:

requiresLoad in interface FetchConfiguration

traverse

public FetchConfiguration traverse(FieldMetaData fm)

Description copied from interface: FetchConfiguration

Traverse the given field to generate (possibly) a new configuration state.

Specified by:

traverse in interface FetchConfiguration

Returns:

a new configuration state resulting out of traversal

toString

public String toString()

Overrides:

toString in class Object