org.apache.jackrabbit.core.persistence.pool
Class BundleDbPersistenceManager

java.lang.Object
  org.apache.jackrabbit.core.persistence.bundle.AbstractBundlePersistenceManager
      org.apache.jackrabbit.core.persistence.pool.BundleDbPersistenceManager

All Implemented Interfaces:

CachingPersistenceManager, IterablePersistenceManager, PersistenceManager, DatabaseAware

Direct Known Subclasses:

DerbyPersistenceManager, H2PersistenceManager, MSSqlPersistenceManager, MySqlPersistenceManager, OraclePersistenceManager, PostgreSQLPersistenceManager

public class BundleDbPersistenceManager
extends AbstractBundlePersistenceManager
implements DatabaseAware

This is a generic persistence manager that stores the NodePropBundles in a database.

Configuration:

• <param name="bundleCacheSize" value="8"/>
• <param name="consistencyCheck" value="false"/>
• <param name="consistencyFix" value="false"/>
• <param name="minBlobSize" value="4096"/>
• <param name="driver" value=""/>
• <param name="url" value=""/>
• <param name="user" value=""/>
• <param name="password" value=""/>
• <param name="databaseType" value=""/>
• <param name="schemaObjectPrefix" value=""/>
• <param name="errorHandling" value=""/>
• <param name="blockOnConnectionLoss" value="false"/>
• <param name="schemaCheckEnabled" value="true"/>

Nested Class Summary

protected static interface	BundleDbPersistenceManager.CloseableBLOBStore Helper interface for closeable stores
protected class	BundleDbPersistenceManager.DbBlobStore Implementation of a blob store that stores the data inside the database
protected class	BundleDbPersistenceManager.FSBlobStore own implementation of the filesystem blob store that uses a different blob-id scheme.

Field Summary

protected BundleBinding	binding the bundle binding
protected BundleDbPersistenceManager.CloseableBLOBStore	blobStore file system where BLOB data is stored
protected boolean	blockOnConnectionLoss indicates whether to block if the database connection is lost
protected String	bundleDeleteSQL
protected String	bundleInsertSQL
protected String	bundleSelectAllIdsFromSQL
protected String	bundleSelectAllIdsSQL
protected String	bundleSelectSQL
protected String	bundleUpdateSQL
protected ConnectionHelper	conHelper the ConnectionHelper set in the init(PMContext) method
protected boolean	consistencyCheck flag indicating if a consistency check should be issued during startup
protected boolean	consistencyFix flag indicating if the consistency check should attempt to fix issues
protected String	databaseType the database type
protected String	dataSourceName the logical name of the data source to use
protected String	driver the jdbc driver name
protected ErrorHandling	errorHandling flag for error handling
protected boolean	externalBLOBs indicates if uses (filesystem) blob store
protected static int	INITIAL_BUFFER_SIZE initial size of buffer used to serialize objects
protected boolean	initialized flag indicating if this manager was initialized
protected String	nodeReferenceDeleteSQL
protected String	nodeReferenceInsertSQL
protected String	nodeReferenceSelectSQL
protected String	nodeReferenceUpdateSQL
protected String	password the jdbc password
protected String	schemaObjectPrefix the prefix for the database objects
static int	SM_BINARY_KEYS storage model modifier: binary keys
static int	SM_LONGLONG_KEYS storage model modifier: longlong keys
protected String	url the jdbc url string
protected String	user the jdbc user

Fields inherited from class org.apache.jackrabbit.core.persistence.bundle.AbstractBundlePersistenceManager

context, NODEFILENAME, NODEREFSFILENAME, RES_NAME_INDEX, RES_NS_INDEX

Constructor Summary

BundleDbPersistenceManager()

Method Summary

protected void	buildSQLStatements() Initializes the SQL strings.
protected void	checkBundleConsistency(NodeId id, NodePropBundle bundle, boolean fix, Collection<NodePropBundle> modifications) Checks a single bundle for inconsistencies, ie. inexistent child nodes and inexistent parents.
void	checkConsistency(String[] uuids, boolean recursive, boolean fix) This implementation does nothing.
void	close() Closes the persistence manager.
protected BundleDbPersistenceManager.CloseableBLOBStore	createBlobStore() Creates a suitable blobstore
protected CheckSchemaOperation	createCheckSchemaOperation() This method is called from init(PMContext) after the createConnectionHelper(DataSource) method, and returns a default CheckSchemaOperation.
protected ConnectionHelper	createConnectionHelper(DataSource dataSrc) This method is called from the init(PMContext) method of this class and returns a ConnectionHelper instance which is assigned to the conHelper field.
protected BundleDbPersistenceManager.CloseableBLOBStore	createDBBlobStore(PMContext context) Creates a blob store that uses the database.
protected DbNameIndex	createDbNameIndex() Returns a new instance of a DbNameIndex.
protected BundleDbPersistenceManager.CloseableBLOBStore	createLocalFSBlobStore(PMContext context) Creates a blob store that is based on a local fs.
protected Object[]	createParams(NodeId id, Object p, boolean before) Creates a parameter array for an SQL statement that needs (i) a node identifier, and (2) another parameter.
void	destroy(NodeReferences refs) Deletes the node references from the underlying system.
protected void	destroyBundle(NodePropBundle bundle) Deletes the bundle from the underlying system.
boolean	existsReferencesTo(NodeId targetId) Checks whether references of the identified target node exist.
Iterable<NodeId>	getAllNodeIds(NodeId bigger, int maxCount) Get all node ids.
protected BLOBStore	getBlobStore() Returns the BLOB store used by this persistence manager.
String	getBlockOnConnectionLoss()
String	getConsistencyCheck() Checks if consistency check is enabled.
String	getConsistencyFix() Checks if consistency fix is enabled.
String	getDatabaseType() Returns the configured database type name.
String	getDataSourceName()
String	getDriver() Returns the class name of the JDBC driver.
String	getErrorHandling() Returns the error handling configuration of this manager
protected Object[]	getKey(NodeId id) Constructs a parameter list for a PreparedStatement for the given node identifier.
String	getMinBlobSize() Returns the minimum blob size in bytes.
StringIndex	getNameIndex() Returns the local name index
String	getPassword() Returns the configured password that is used to establish JDBC connections.
String	getSchema() Deprecated. This method is deprecated; getDatabaseType should be used instead.
String	getSchemaObjectPrefix() Returns the configured schema object prefix.
int	getStorageModel() returns the storage model
String	getUrl() Returns the configured JDBC connection url.
String	getUser() Returns the configured user that is used to establish JDBC connections.
void	init(PMContext context) Initializes the persistence manager.
boolean	isExternalBLOBs() Returns if uses external (filesystem) blob store.
boolean	isSchemaCheckEnabled()
protected NodePropBundle	loadBundle(NodeId id) Loads a bundle from the underlying system.
NodeReferences	loadReferencesTo(NodeId targetId) Load the persisted references to the node with the given identifier.
void	setBlockOnConnectionLoss(String block)
void	setConnectionFactory(ConnectionFactory connnectionFactory)
void	setConsistencyCheck(String consistencyCheck) Defines if a consistency check is to be performed on initialization.
void	setConsistencyFix(String consistencyFix) Defines if the consistency check should attempt to fix issues that it finds.
void	setDatabaseType(String databaseType) Sets the database type.
void	setDataSourceName(String dataSourceName)
void	setDriver(String driver) Sets the class name of the JDBC driver.
void	setErrorHandling(String errorHandling) Sets the error handling behaviour of this manager.
void	setExternalBLOBs(boolean externalBLOBs) Sets the flag for external (filesystem) blob store usage.
void	setMinBlobSize(String minBlobSize) Sets the minimum blob size.
void	setPassword(String password) Sets the password that will be used to establish JDBC connections.
void	setSchema(String databaseType) Deprecated. This method is deprecated; setDatabaseType should be used instead.
void	setSchemaCheckEnabled(boolean enabled)
void	setSchemaObjectPrefix(String schemaObjectPrefix) Sets the schema object prefix.
void	setUrl(String url) Sets the JDBC connection URL.
void	setUser(String user) Sets the user name that will be used to establish JDBC connections.
void	store(ChangeLog changeLog) Right now, this iterates over all items in the changelog and calls the individual methods that handle single item states or node references objects.
void	store(NodeReferences refs) Stores a node references to the underlying system.
protected void	storeBundle(NodePropBundle bundle) Stores a bundle to the underlying system.
String	toString()
boolean	useDbBlobStore() Returns true if the blobs are stored in the DB.
boolean	useLocalFsBlobStore() Returns true if the blobs are stored in the local fs.

Methods inherited from class org.apache.jackrabbit.core.persistence.bundle.AbstractBundlePersistenceManager

buildBlobFilePath, buildNodeFilePath, buildNodeFolderPath, buildNodeReferencesFilePath, buildPropFilePath, createNew, createNew, evictBundle, exists, exists, getBundleCacheSize, getNsIndex, load, load, onExternalUpdate, setBundleCacheSize

Methods inherited from class java.lang.Object

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

Field Detail

SM_BINARY_KEYS

public static final int SM_BINARY_KEYS

storage model modifier: binary keys

See Also:

Constant Field Values

SM_LONGLONG_KEYS

public static final int SM_LONGLONG_KEYS

storage model modifier: longlong keys

See Also:

Constant Field Values

initialized

protected boolean initialized

flag indicating if this manager was initialized

driver

protected String driver

the jdbc driver name

url

protected String url

the jdbc url string

user

protected String user

the jdbc user

password

protected String password

the jdbc password

databaseType

protected String databaseType

the database type

dataSourceName

protected String dataSourceName

the logical name of the data source to use

conHelper

protected ConnectionHelper conHelper

the ConnectionHelper set in the init(PMContext) method

schemaObjectPrefix

protected String schemaObjectPrefix

the prefix for the database objects

consistencyCheck

protected boolean consistencyCheck

flag indicating if a consistency check should be issued during startup

consistencyFix

protected boolean consistencyFix

flag indicating if the consistency check should attempt to fix issues

INITIAL_BUFFER_SIZE

protected static final int INITIAL_BUFFER_SIZE

initial size of buffer used to serialize objects

See Also:

Constant Field Values

externalBLOBs

protected boolean externalBLOBs

indicates if uses (filesystem) blob store

blockOnConnectionLoss

protected boolean blockOnConnectionLoss

indicates whether to block if the database connection is lost

bundleInsertSQL

protected String bundleInsertSQL

bundleUpdateSQL

protected String bundleUpdateSQL

bundleSelectSQL

protected String bundleSelectSQL

bundleDeleteSQL

protected String bundleDeleteSQL

bundleSelectAllIdsFromSQL

protected String bundleSelectAllIdsFromSQL

bundleSelectAllIdsSQL

protected String bundleSelectAllIdsSQL

nodeReferenceInsertSQL

protected String nodeReferenceInsertSQL

nodeReferenceUpdateSQL

protected String nodeReferenceUpdateSQL

nodeReferenceSelectSQL

protected String nodeReferenceSelectSQL

nodeReferenceDeleteSQL

protected String nodeReferenceDeleteSQL

blobStore

protected BundleDbPersistenceManager.CloseableBLOBStore blobStore

file system where BLOB data is stored

errorHandling

protected ErrorHandling errorHandling

flag for error handling

binding

protected BundleBinding binding

the bundle binding

Constructor Detail

BundleDbPersistenceManager

public BundleDbPersistenceManager()

Method Detail

setConnectionFactory

public void setConnectionFactory(ConnectionFactory connnectionFactory)

Specified by:

setConnectionFactory in interface DatabaseAware

getUrl

public String getUrl()

Returns the configured JDBC connection url.

Returns:

the configured JDBC connection url.

setUrl

public void setUrl(String url)

Sets the JDBC connection URL. The connection can be created using a JNDI Data Source as well. To do that, the driver class name must reference a javax.naming.Context class (for example javax.naming.InitialContext), and the URL must be the JNDI URL (for example java:comp/env/jdbc/Test).

Parameters:

url - the url to set.

getUser

public String getUser()

Returns the configured user that is used to establish JDBC connections.

Returns:

the JDBC user.

setUser

public void setUser(String user)

Sets the user name that will be used to establish JDBC connections.

Parameters:

user - the user name.

getPassword

public String getPassword()

Returns the configured password that is used to establish JDBC connections.

Returns:

the password.

setPassword

public void setPassword(String password)

Sets the password that will be used to establish JDBC connections.

Parameters:

password - the password for the connection

getDriver

public String getDriver()

Returns the class name of the JDBC driver.

Returns:

the class name of the JDBC driver.

setDriver

public void setDriver(String driver)

Sets the class name of the JDBC driver. The driver class will be loaded during init in order to assure the existence. If no driver is specified, the default driver for the database is used.

Parameters:

driver - the class name of the driver

getSchemaObjectPrefix

public String getSchemaObjectPrefix()

Returns the configured schema object prefix.

Returns:

the configured schema object prefix.

setSchemaObjectPrefix

public void setSchemaObjectPrefix(String schemaObjectPrefix)

Sets the schema object prefix. This string is used to prefix all schema objects, like tables and indexes. this is useful, if several persistence managers use the same database.

Parameters:

schemaObjectPrefix - the prefix for schema objects.

getSchema

public String getSchema()

Deprecated. This method is deprecated; getDatabaseType should be used instead.

Returns the configured database type name.

Returns:

the database type name.

getDatabaseType

public String getDatabaseType()

Returns the configured database type name.

Returns:

the database type name.

setSchema

public void setSchema(String databaseType)

Deprecated. This method is deprecated; setDatabaseType should be used instead.

Sets the database type. This identifier is used to load and execute the respective .ddl resource in order to create the required schema objects.

Parameters:

database - type name

setDatabaseType

public void setDatabaseType(String databaseType)

Sets the database type. This identifier is used to load and execute the respective .ddl resource in order to create the required schema objects.

Parameters:

database - type name

getDataSourceName

public String getDataSourceName()

setDataSourceName

public void setDataSourceName(String dataSourceName)

isExternalBLOBs

public boolean isExternalBLOBs()

Returns if uses external (filesystem) blob store.

Returns:

if uses external (filesystem) blob store.

setExternalBLOBs

public void setExternalBLOBs(boolean externalBLOBs)

Sets the flag for external (filesystem) blob store usage.

Parameters:

externalBLOBs - a value of "true" indicates that an external blob store is to be used.

getConsistencyCheck

public String getConsistencyCheck()

Checks if consistency check is enabled.

Returns:

true if consistency check is enabled.

setConsistencyCheck

public void setConsistencyCheck(String consistencyCheck)

Defines if a consistency check is to be performed on initialization.

Parameters:

consistencyCheck - the consistency check flag.

getConsistencyFix

public String getConsistencyFix()

Checks if consistency fix is enabled.

Returns:

true if consistency fix is enabled.

setConsistencyFix

public void setConsistencyFix(String consistencyFix)

Defines if the consistency check should attempt to fix issues that it finds.

Parameters:

consistencyFix - the consistency fix flag.

getMinBlobSize

public String getMinBlobSize()

Returns the minimum blob size in bytes.

Returns:

the minimum blob size in bytes.

setMinBlobSize

public void setMinBlobSize(String minBlobSize)

Sets the minimum blob size. This size defines the threshold of which size a property is included in the bundle or is stored in the blob store.

Parameters:

minBlobSize - the minimum blob size in bytes.

setErrorHandling

public void setErrorHandling(String errorHandling)

Sets the error handling behaviour of this manager. See ErrorHandling for details about the flags.

Parameters:

errorHandling - the error handling flags

getErrorHandling

public String getErrorHandling()

Returns the error handling configuration of this manager

Returns:

the error handling configuration of this manager

setBlockOnConnectionLoss

public void setBlockOnConnectionLoss(String block)

getBlockOnConnectionLoss

public String getBlockOnConnectionLoss()

useDbBlobStore

public boolean useDbBlobStore()

Returns true if the blobs are stored in the DB.

Returns:

true if the blobs are stored in the DB.

useLocalFsBlobStore

public boolean useLocalFsBlobStore()

Returns true if the blobs are stored in the local fs.

Returns:

true if the blobs are stored in the local fs.

isSchemaCheckEnabled

public final boolean isSchemaCheckEnabled()

Returns:

whether the schema check is enabled

setSchemaCheckEnabled

public final void setSchemaCheckEnabled(boolean enabled)

Parameters:

enabled - set whether the schema check is enabled

store

public void store(ChangeLog changeLog)
           throws ItemStateException

Right now, this iterates over all items in the changelog and calls the individual methods that handle single item states or node references objects. Properly implemented, this method should ensure that changes are either written completely to the underlying persistence layer, or not at all. Atomically saves the given set of changes. Basically wraps a JDBC transaction around super.store(). FIXME: the retry logic is almost a duplicate of ConnectionHelper.RetryManager.

Specified by:

store in interface PersistenceManager

Overrides:

store in class AbstractBundlePersistenceManager

Parameters:

changeLog - change log containing states that were changed

Throws:

ItemStateException - if the changes could not be saved

init

public void init(PMContext context)
          throws Exception

Initializes the persistence manager. The persistence manager is permanently bound to the given context, and any required external resources are acquired.

An appropriate exception is thrown if the persistence manager initialization fails for whatever reason. In this case the state of the persistence manager is undefined and the instance should be discarded. Initializes the internal structures of this abstract persistence manager.

Specified by:

init in interface PersistenceManager

Overrides:

init in class AbstractBundlePersistenceManager

Parameters:

context - persistence manager context

Throws:

Exception - if the persistence manager initialization failed

createConnectionHelper

protected ConnectionHelper createConnectionHelper(DataSource dataSrc)
                                           throws Exception

This method is called from the init(PMContext) method of this class and returns a ConnectionHelper instance which is assigned to the conHelper field. Subclasses may override it to return a specialized connection helper.

Parameters:

dataSrc - the DataSource of this persistence manager

Returns:

a ConnectionHelper

Throws:

Exception - on error

createCheckSchemaOperation

protected CheckSchemaOperation createCheckSchemaOperation()

This method is called from init(PMContext) after the createConnectionHelper(DataSource) method, and returns a default CheckSchemaOperation. Subclasses can overrride this implementation to get a customized implementation.

Returns:

a new CheckSchemaOperation instance

getBlobStore

protected BLOBStore getBlobStore()

Returns the BLOB store used by this persistence manager.

Specified by:

getBlobStore in class AbstractBundlePersistenceManager

Returns:

BLOB store

createBlobStore

protected BundleDbPersistenceManager.CloseableBLOBStore createBlobStore()
                                                                 throws Exception

Creates a suitable blobstore

Returns:

a blobstore

Throws:

Exception - if an unspecified error occurs

getNameIndex

public StringIndex getNameIndex()

Returns the local name index

Overrides:

getNameIndex in class AbstractBundlePersistenceManager

Returns:

the local name index

Throws:

IllegalStateException - if an error occurs.

createDbNameIndex

protected DbNameIndex createDbNameIndex()
                                 throws SQLException

Returns a new instance of a DbNameIndex.

Returns:

a new instance of a DbNameIndex.

Throws:

SQLException - if an SQL error occurs.

getStorageModel

public int getStorageModel()

returns the storage model

Returns:

the storage model

createLocalFSBlobStore

protected BundleDbPersistenceManager.CloseableBLOBStore createLocalFSBlobStore(PMContext context)
                                                                        throws Exception

Creates a blob store that is based on a local fs. This is called by init if useLocalFsBlobStore() returns true.

Parameters:

context - the persistence manager context

Returns:

a blob store

Throws:

Exception - if an error occurs.

createDBBlobStore

protected BundleDbPersistenceManager.CloseableBLOBStore createDBBlobStore(PMContext context)
                                                                   throws Exception

Creates a blob store that uses the database. This is called by init if useDbBlobStore() returns true.

Parameters:

context - the persistence manager context

Returns:

a blob store

Throws:

Exception - if an error occurs.

checkBundleConsistency

protected void checkBundleConsistency(NodeId id,
                                      NodePropBundle bundle,
                                      boolean fix,
                                      Collection<NodePropBundle> modifications)

Checks a single bundle for inconsistencies, ie. inexistent child nodes and inexistent parents.

Parameters:

id - node id for the bundle to check

bundle - the bundle to check

fix - if true, repair things that can be repaired

modifications - if fix == true, collect the repaired bundles here

checkConsistency

public void checkConsistency(String[] uuids,
                             boolean recursive,
                             boolean fix)

Description copied from class: AbstractBundlePersistenceManager

This implementation does nothing. Perform a consistency check of the data. An example are non-existent nodes referenced in a child node entry. The existence of this feature and the scope of the implementation can vary in different PersistenceManager implementations.

Specified by:

checkConsistency in interface PersistenceManager

Overrides:

checkConsistency in class AbstractBundlePersistenceManager

Parameters:

uuids - list of UUIDs of nodes to be checked. if null, all nodes will be checked

recursive - if true, the tree(s) below the given node(s) will be traversed and checked as well

fix - if true, any problems found that can be repaired will be repaired. if false, no data will be modified, instead all inconsistencies will only get logged

close

public void close()
           throws Exception

Closes the persistence manager. The consistency of the persistent storage is guaranteed and all acquired resources are released. It is an error to invoke any methods on a closed persistence manager, and implementations are free to enforce this constraint by throwing IllegalStateExceptions in such cases.

An appropriate exception is thrown if the persistence manager could not be closed properly. In this case the state of the persistence manager is undefined and the instance should be discarded. Closes the persistence manager, release acquired resources.

Specified by:

close in interface PersistenceManager

Overrides:

close in class AbstractBundlePersistenceManager

Throws:

Exception - if the persistence manager failed to close properly

getKey

protected Object[] getKey(NodeId id)

Constructs a parameter list for a PreparedStatement for the given node identifier.

Parameters:

id - the node id

Returns:

a list of Objects

createParams

protected Object[] createParams(NodeId id,
                                Object p,
                                boolean before)

Creates a parameter array for an SQL statement that needs (i) a node identifier, and (2) another parameter.

Parameters:

id - the node id

p - the other parameter

before - whether the other parameter should be before the uuid parameter

Returns:

an Object array that represents the parameters

getAllNodeIds

public Iterable<NodeId> getAllNodeIds(NodeId bigger,
                                      int maxCount)
                               throws ItemStateException,
                                      RepositoryException

Get all node ids. A typical application will call this method multiple times, where 'after' is the last row read. The maxCount parameter defines the maximum number of node ids returned, 0 meaning no limit. The order of the node ids is specific for the given persistent manager. Items that are added concurrently may not be included.

Specified by:

getAllNodeIds in interface IterablePersistenceManager

Parameters:

bigger - the lower limit, or null for no limit.

maxCount - the maximum number of node ids to return, or 0 for no limit.

Returns:

an iterator of all bundles.

Throws:

ItemStateException - if an error while loading occurs.

RepositoryException - if a repository exception occurs

loadBundle

protected NodePropBundle loadBundle(NodeId id)
                             throws ItemStateException

Loads a bundle from the underlying system.

Specified by:

loadBundle in class AbstractBundlePersistenceManager

Parameters:

id - the node id of the bundle

Returns:

the loaded bundle or null if the bundle does not exist.

Throws:

ItemStateException - if an error while loading occurs.

storeBundle

protected void storeBundle(NodePropBundle bundle)
                    throws ItemStateException

Stores a bundle to the underlying system.

Specified by:

storeBundle in class AbstractBundlePersistenceManager

Parameters:

bundle - the bundle to store

Throws:

ItemStateException - if an error while storing occurs.

destroyBundle

protected void destroyBundle(NodePropBundle bundle)
                      throws ItemStateException

Deletes the bundle from the underlying system.

Specified by:

destroyBundle in class AbstractBundlePersistenceManager

Parameters:

bundle - the bundle to destroy

Throws:

ItemStateException - if an error while destroying occurs.

loadReferencesTo

public NodeReferences loadReferencesTo(NodeId targetId)
                                throws NoSuchItemStateException,
                                       ItemStateException

Load the persisted references to the node with the given identifier.

Specified by:

loadReferencesTo in interface PersistenceManager

Parameters:

targetId - reference target node id

Throws:

NoSuchItemStateException - if the target node does not exist

ItemStateException - if another error occurs

store

public void store(NodeReferences refs)
           throws ItemStateException

Stores a node references to the underlying system. This method uses shared PreparedStatements, which must be used strictly sequentially. Because this method synchronizes on the persistence manager instance, there is no need to synchronize on the shared statement. If the method would not be synchronized, the shared statement must be synchronized.

Specified by:

store in class AbstractBundlePersistenceManager

Parameters:

refs - the node references to store.

Throws:

ItemStateException - if an error while storing occurs.

destroy

public void destroy(NodeReferences refs)
             throws ItemStateException

Deletes the node references from the underlying system.

Specified by:

destroy in class AbstractBundlePersistenceManager

Parameters:

refs - the node references to destroy.

Throws:

ItemStateException - if an error while destroying occurs.

existsReferencesTo

public boolean existsReferencesTo(NodeId targetId)
                           throws ItemStateException

Checks whether references of the identified target node exist.

Specified by:

existsReferencesTo in interface PersistenceManager

Parameters:

targetId - target node id

Returns:

true if the references exist, false otherwise

Throws:

ItemStateException - on persistence manager errors

toString

public String toString()

Overrides:

toString in class Object

buildSQLStatements

protected void buildSQLStatements()

Initializes the SQL strings.