Class AbstractDatabaseImpl
- java.lang.Object
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- org.exolab.castor.jdo.engine.AbstractDatabaseImpl
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- All Implemented Interfaces:
Database
- Direct Known Subclasses:
GlobalDatabaseImpl
,LocalDatabaseImpl
public abstract class AbstractDatabaseImpl extends java.lang.Object implements Database
An implementation of the JDO database supporting explicit transaction demarcation.- Version:
- $Revision: 8351 $ $Date: 2006-04-22 11:05:30 -0600 (Sat, 22 Apr 2006) $
- Author:
- Assaf Arkin, Bruce Snyder
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Field Summary
Fields Modifier and Type Field Description protected boolean
_autoStore
True if user prefer all reachable object to be stored automatically.protected CallbackInterceptor
_callback
The default callback interceptor for transaction.protected java.lang.ClassLoader
_classLoader
The class loader for application classes (may be null).protected TransactionContext
_ctx
The transaction context is this database was accessed with anXAResource
.protected java.lang.String
_dbName
The name of this database.protected InstanceFactory
_instanceFactory
The instance factory to that creates new instances of data object.protected int
_lockTimeout
The lock timeout for this database.protected PersistenceInfoGroup
_scope
The database engine used to access the underlying SQL database.
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Constructor Summary
Constructors Constructor Description AbstractDatabaseImpl(java.lang.String dbName, int lockTimeout, CallbackInterceptor callback, InstanceFactory instanceFactory, java.lang.ClassLoader classLoader, boolean autoStore)
Creates an instance of this class.
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Method Summary
All Methods Instance Methods Abstract Methods Concrete Methods Modifier and Type Method Description abstract void
begin()
Begin a new transaction.abstract void
close()
Closes the database.abstract void
commit()
Commits and closes the transaction.void
create(java.lang.Object object)
Creates a new object in persistent storage.CacheManager
getCacheManager()
Get's the CacheManager instance.java.lang.ClassLoader
getClassLoader()
Gets the current application ClassLoader's instance.TransactionContext
getCurrentTransaction()
Gets the current Castor transaction in use.java.lang.String
getDatabaseName()
Return the name of the database.Identity
getIdentity(java.lang.Object object)
Returns the object's identity.abstract java.sql.Connection
getJdbcConnection()
Gets the underlying JDBC connection.(package private) LockEngine
getLockEngine()
Returns theLockEngine
in use by this database instance.OQLQuery
getNamedQuery(java.lang.String name)
Creates an OQL query based upon a named query as defined in the mapping file.OQLQuery
getNativeQuery(java.lang.String sql, java.lang.Class<?> result)
Creates an OQL query instance based upon a native SQL query and a returning (resulting) class.OQLQuery
getOQLQuery()
Creates an OQL query with no statement.OQLQuery
getOQLQuery(java.lang.String oql)
Creates an OQL query from the supplied statement.Query
getQuery()
Creates an empty query.PersistenceInfoGroup
getScope()
protected TransactionContext
getTransaction()
Returns the currently active transaction, if any.boolean
isActive()
Returns true if a transaction is currently active.boolean
isAutoStore()
Return if the current transaction is set to autoStore, it there is transaction active.boolean
isClosed()
Returns true if the database is closed.boolean
isLocked(java.lang.Class cls, java.lang.Object identity)
Returns true if the specified object is currently locked.boolean
isPersistent(java.lang.Object object)
Returns true if the entity is persistent.<T> T
load(java.lang.Class<T> type, java.lang.Object identity)
Load an object of the specified type and given identity.<T> T
load(java.lang.Class<T> type, java.lang.Object identity, java.lang.Object object)
Load an object of the specified type and given identity into a given instance of object.<T> T
load(java.lang.Class<T> type, java.lang.Object identity, AccessMode mode)
Load an object of the specified type and given identity.protected void
loadSynchronizables()
Load theTxSynchronizable
implementations from the properties file, if not loaded before.void
lock(java.lang.Object object)
Acquire a soft write lock on the object.protected void
registerSynchronizables()
Register theTxSynchronizable
implementations at the TransactionContect at end of begin().void
remove(java.lang.Object object)
Removes the object from persistent storage.abstract void
rollback()
Rolls back and closes the transaction.void
setAutoStore(boolean autoStore)
Indicates whether user prefer all reachable object to be stored automatically; false if user wants dependent object only to be stored.java.lang.String
toString()
protected void
unregisterSynchronizables()
Unregister theTxSynchronizable
implementations at the TransactionContect after commit() or rollback().void
update(java.lang.Object object)
Update a data object which is queried/loaded/created in another transaction.
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Field Detail
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_scope
protected PersistenceInfoGroup _scope
The database engine used to access the underlying SQL database.
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_ctx
protected TransactionContext _ctx
The transaction context is this database was accessed with anXAResource
.
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_lockTimeout
protected int _lockTimeout
The lock timeout for this database. Zero for immediate timeout, an infinite value for no timeout. The timeout is specified in seconds.
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_callback
protected CallbackInterceptor _callback
The default callback interceptor for transaction.
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_instanceFactory
protected InstanceFactory _instanceFactory
The instance factory to that creates new instances of data object.
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_dbName
protected java.lang.String _dbName
The name of this database.
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_autoStore
protected boolean _autoStore
True if user prefer all reachable object to be stored automatically. False if user want only dependent object to be stored.
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_classLoader
protected java.lang.ClassLoader _classLoader
The class loader for application classes (may be null).
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Constructor Detail
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AbstractDatabaseImpl
public AbstractDatabaseImpl(java.lang.String dbName, int lockTimeout, CallbackInterceptor callback, InstanceFactory instanceFactory, java.lang.ClassLoader classLoader, boolean autoStore) throws DatabaseNotFoundException
Creates an instance of this class.- Parameters:
dbName
- Name of the database.lockTimeout
- Lock timeout to use.callback
- Callback interceptors.instanceFactory
- Instance factory.classLoader
- Current class loader.autoStore
- True if auto storing is enabled.- Throws:
DatabaseNotFoundException
- If there's no database configuration for the given name.
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Method Detail
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getLockEngine
LockEngine getLockEngine()
Returns theLockEngine
in use by this database instance.- Returns:
- the
LockEngine
in use by this database instance.
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getScope
public PersistenceInfoGroup getScope()
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setAutoStore
public void setAutoStore(boolean autoStore)
Indicates whether user prefer all reachable object to be stored automatically; false if user wants dependent object only to be stored.- Specified by:
setAutoStore
in interfaceDatabase
- Parameters:
autoStore
- True to indicate that 'autoStore' mode should be used.
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isAutoStore
public boolean isAutoStore()
Return if the current transaction is set to autoStore, it there is transaction active. If there is no active transaction, return if the next transaction will be set to autoStore.- Specified by:
isAutoStore
in interfaceDatabase
- Returns:
- True if 'auto-store' mode is in use.
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getClassLoader
public java.lang.ClassLoader getClassLoader()
Gets the current application ClassLoader's instance.- Specified by:
getClassLoader
in interfaceDatabase
- Returns:
- the current ClassLoader's instance, or
null
if not provided
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getDatabaseName
public java.lang.String getDatabaseName()
Return the name of the database.- Specified by:
getDatabaseName
in interfaceDatabase
- Returns:
- Name of the database.
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close
public abstract void close() throws PersistenceException
Closes the database. If a client transaction is in progress the transaction will be rolled back and an exception thrown. If an app-server transaction is in progress, the transaction will commit/rollback when triggered by the application server.- Specified by:
close
in interfaceDatabase
- Throws:
PersistenceException
- An error occured while attempting to close the database
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isClosed
public boolean isClosed()
Returns true if the database is closed.
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isLocked
public boolean isLocked(java.lang.Class cls, java.lang.Object identity) throws PersistenceException
Returns true if the specified object is currently locked.- Specified by:
isLocked
in interfaceDatabase
- Parameters:
cls
- Class instance.identity
- Object identity.- Returns:
- True if the object specified is locked; false otherwise.
- Throws:
PersistenceException
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load
public <T> T load(java.lang.Class<T> type, java.lang.Object identity) throws PersistenceException
Load an object of the specified type and given identity. Once loaded the object is persistent. Calling this method with the same identity in the same transaction will return the same object. This method is equivalent to a query that returns a single object. If the identity spans on more than one field, all of the identity fields can be wrapped in a Complex object.- Specified by:
load
in interfaceDatabase
- Parameters:
type
- The object's typeidentity
- The object's identity- Returns:
- The object instance.
- Throws:
ObjectNotFoundException
- No object of the given type and identity was found in persistent storageLockNotGrantedException
- Timeout or deadlock occured attempting to acquire a lock on the objectTransactionNotInProgressException
- Method called while transaction is not in progressPersistenceException
- An error reported by the persistence engine
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load
public <T> T load(java.lang.Class<T> type, java.lang.Object identity, java.lang.Object object) throws PersistenceException
Load an object of the specified type and given identity into a given instance of object. Once loaded the object is persistent. Calling this method with the same identity in the same transaction will return the same object. This method is equivalent to a query that returns a single object. If the identity spans on more than one field, all of the identity fields can be wrapped in a Complex object.
- Specified by:
load
in interfaceDatabase
- Parameters:
type
- The object's typeidentity
- The object's identityobject
- The object instance to be loaded into- Returns:
- The object instance.
- Throws:
ObjectNotFoundException
- No object of the given type and identity was found in persistent storageLockNotGrantedException
- Timeout or deadlock occured attempting to acquire a lock on the objectTransactionNotInProgressException
- Method called while transaction is not in progressPersistenceException
- An error reported by the persistence engine
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load
public <T> T load(java.lang.Class<T> type, java.lang.Object identity, AccessMode mode) throws PersistenceException
Load an object of the specified type and given identity. Once loaded the object is persistent. Calling this method with the same identity in the same transaction will return the same object. This method is equivalent to a query that returns a single object.
- Specified by:
load
in interfaceDatabase
- Parameters:
type
- The object's typeidentity
- The object's identitymode
- The access mode- Returns:
- The object instance.
- Throws:
ObjectNotFoundException
- No object of the given type and identity was found in persistent storageLockNotGrantedException
- Timeout or deadlock occured attempting to acquire a lock on the objectTransactionNotInProgressException
- Method called while transaction is not in progressPersistenceException
- An error reported by the persistence engine
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create
public void create(java.lang.Object object) throws PersistenceException
Creates a new object in persistent storage. The object will be persisted only if the transaction commits.If the object has an identity then duplicate identity check happens in this method, and the object is visible to queries in this transaction. If the identity is null, duplicate identity check occurs when the transaction completes and the object is not visible to queries until the transaction commits.
- Specified by:
create
in interfaceDatabase
- Parameters:
object
- The object to create- Throws:
TransactionNotInProgressException
- Method called while transaction is not in progressDuplicateIdentityException
- An object with this identity already exists in persistent storageClassNotPersistenceCapableException
- The class is not persistent capablePersistenceException
- An error reported by the persistence engine
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getCacheManager
public CacheManager getCacheManager()
Get's the CacheManager instance. Call getCacheManager for every Database-instances.- Specified by:
getCacheManager
in interfaceDatabase
- Returns:
- the CacheManager-instance.
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update
public void update(java.lang.Object object) throws PersistenceException
Update a data object which is queried/loaded/created in another transaction. This method is used only for long transaction support. Calling this method for data object queried/loaded/created in the same transaction results in Exception.For example, the data object may be sent to a client application and dispayed to a user. After that the objects is being modified in the client application, the object returns back and is update to the database in the second transaction.
See Long Transaction on Castor website.
- Specified by:
update
in interfaceDatabase
- Parameters:
object
- The object to create- Throws:
TransactionNotInProgressException
- Method called while transaction is not in progressClassNotPersistenceCapableException
- The class is not persistent capablePersistenceException
- An error reported by the persistence engine
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remove
public void remove(java.lang.Object object) throws PersistenceException
Removes the object from persistent storage. The deletion will take effect only if the transaction is committed, but the object is no longer visible to queries in the current transaction and locks for access from other transactions will block until this transaction completes.- Specified by:
remove
in interfaceDatabase
- Parameters:
object
- The object to remove- Throws:
TransactionNotInProgressException
- Method called while transaction is not in progressObjectNotPersistentException
- The object has not been queried or created in this transactionLockNotGrantedException
- Timeout or deadlock occured attempting to acquire a lock on the objectPersistenceException
- An error reported by the persistence engine
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isPersistent
public boolean isPersistent(java.lang.Object object)
Returns true if the entity is persistent. An entity is persistent if it was created or loaded but not removed in this transaction. If the entity was created or loaded in another transaction, or there is no open transaction, this method returns false.- Specified by:
isPersistent
in interfaceDatabase
- Parameters:
object
- The entity.- Returns:
- True if entity is persistent in this transaction.
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getIdentity
public Identity getIdentity(java.lang.Object object) throws PersistenceException
Returns the object's identity. The identity will be determined by calling the getters of the fields defined as identities in the mapping. If a mapping for the objects class could not be found a ClassNotPersistenceCapableException will be thrown. Null is only returned if the objects identity is null. It is not required to have an active transaction when using this method.Note: Prior to 0.9.9.1 release of castor the identity could only be determined if the object took part in the transaction. If this was not the case, the previous implementation also returned null.
- Specified by:
getIdentity
in interfaceDatabase
- Parameters:
object
- The object.- Returns:
- The object's identity, or null.
- Throws:
PersistenceException
- The class is not persistent capable.
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lock
public void lock(java.lang.Object object) throws PersistenceException
Acquire a soft write lock on the object. Read locks are implicitly available when the object is queried. A write lock is only granted for objects that are created or deleted or for objects loaded in exclusive mode - this method can obtain such a lock explicitly.A soft lock is acquired in memory, not in the database. To acquire a lock in the database, use the locked access mode.
If the object already has a write lock in this transaction or a read lock in this transaction but no read lock in any other transaction, a write lock is obtained. If this object has a read lock in any other transaction this method will block until the other transaction will release its lock. If the timeout has elapsed or a deadlock has been detected, an exception will be thrown but the current lock will be retained.
- Specified by:
lock
in interfaceDatabase
- Parameters:
object
- The object to lock- Throws:
TransactionNotInProgressException
- Method called while transaction is not in progressObjectNotPersistentException
- The object has not been queried or created in this transactionLockNotGrantedException
- Timeout or deadlock occured attempting to acquire a lock on the objectPersistenceException
- An error reported by the persistence engine
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getOQLQuery
public OQLQuery getOQLQuery()
Creates an OQL query with no statement.OQLQuery.create(java.lang.String)
must be called before the query can be executed.- Specified by:
getOQLQuery
in interfaceDatabase
- Returns:
- An OQL query
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getNamedQuery
public final OQLQuery getNamedQuery(java.lang.String name) throws PersistenceException
Creates an OQL query based upon a named query as defined in the mapping file.OQLQuery.create(java.lang.String)
- Specified by:
getNamedQuery
in interfaceDatabase
- Parameters:
name
- Name of the (named) query to create.- Returns:
- An OQL query
- Throws:
PersistenceException
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getNativeQuery
public final OQLQuery getNativeQuery(java.lang.String sql, java.lang.Class<?> result) throws PersistenceException
Creates an OQL query instance based upon a native SQL query and a returning (resulting) class.- Specified by:
getNativeQuery
in interfaceDatabase
- Parameters:
sql
- Native SQL query to be used.result
- Class that is result of the query.- Returns:
- An OQL query
- Throws:
PersistenceException
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getOQLQuery
public OQLQuery getOQLQuery(java.lang.String oql) throws PersistenceException
Creates an OQL query from the supplied statement.- Specified by:
getOQLQuery
in interfaceDatabase
- Parameters:
oql
- An OQL query statement- Returns:
- An OQL query
- Throws:
PersistenceException
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getQuery
public Query getQuery()
Creates an empty query. The query must be created before it can be executed.
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getTransaction
protected TransactionContext getTransaction() throws TransactionNotInProgressException
Returns the currently active transaction, if any.- Returns:
- The current active transaction.
- Throws:
TransactionNotInProgressException
- If there's no active transaction.
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begin
public abstract void begin() throws PersistenceException
Begin a new transaction. A transaction must be open in order to query and persist objects.- Specified by:
begin
in interfaceDatabase
- Throws:
PersistenceException
- A transaction is already open on this database, or an error reported by the persistence engine
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commit
public abstract void commit() throws TransactionNotInProgressException, TransactionAbortedException
Commits and closes the transaction. All changes made to persistent objects during the transaction are made persistent; objects created during the transaction are made durable; and, objects removed during the transaction are removed from the database.In other words, any modifications to any data objects which are queried/loaded/created/update to this database is automatically stored to the database and visible to subsequence transactions. (ie. update is solely used for long transaction support and should not be called for any data object queried/loaded/created in the this transaction.)
If the transaction cannot commit, the entire transaction rolls back and a
TransactionAbortedException
exception is thrown.After this method returns, the transaction is closed and all persistent objects are transient. Using
Database.begin()
to open a new transaction will not restore objects to their persistent stage.- Specified by:
commit
in interfaceDatabase
- Throws:
TransactionNotInProgressException
- Method called while transaction is not in progressTransactionAbortedException
- The transaction cannot commit and has been rolled back
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rollback
public abstract void rollback() throws TransactionNotInProgressException
Rolls back and closes the transaction. All changes made to persistent objects during the transaction are lost, objects created during the transaction are not made durable and objects removed during the transaction continue to exist.- Specified by:
rollback
in interfaceDatabase
- Throws:
TransactionNotInProgressException
- Method called while transaction is not in progress
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isActive
public boolean isActive()
Returns true if a transaction is currently active.
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toString
public java.lang.String toString()
- Overrides:
toString
in classjava.lang.Object
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getJdbcConnection
public abstract java.sql.Connection getJdbcConnection() throws PersistenceException
Gets the underlying JDBC connection. This is for advanced use only. Please make sure that you never close this Connection instance, as it will be closed by Castor.- Specified by:
getJdbcConnection
in interfaceDatabase
- Returns:
- the underlying JDBC connection, if present; otherwise null
- Throws:
PersistenceException
- If the underlying JDBC connection cannot be obtained.
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loadSynchronizables
protected void loadSynchronizables()
Load theTxSynchronizable
implementations from the properties file, if not loaded before.
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registerSynchronizables
protected void registerSynchronizables()
Register theTxSynchronizable
implementations at the TransactionContect at end of begin().
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unregisterSynchronizables
protected void unregisterSynchronizables()
Unregister theTxSynchronizable
implementations at the TransactionContect after commit() or rollback().
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getCurrentTransaction
public TransactionContext getCurrentTransaction() throws TransactionNotInProgressException
Gets the current Castor transaction in use.- Returns:
- the current Castor
- Throws:
TransactionNotInProgressException
- If there's no transaction in progress.
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