Persistence Manager Factory
Any JDO-enabled application will require at least one PersistenceManagerFactory.
Typically applications create one per datastore being utilised. A
PersistenceManagerFactory provides access to PersistenceManagers which allow
objects to be persisted, and retrieved. The PersistenceManagerFactory can be configured
to provide particular behaviour.
The simplest way of creating a PersistenceManagerFactory
is as follows
Properties properties = new Properties();
properties.setProperty("javax.jdo.PersistenceManagerFactoryClass",
"{my_implementation_pmf_class}");
properties.setProperty("javax.jdo.option.ConnectionDriverName","com.mysql.jdbc.Driver");
properties.setProperty("javax.jdo.option.ConnectionURL","jdbc:mysql://localhost/myDB");
properties.setProperty("javax.jdo.option.ConnectionUserName","login");
properties.setProperty("javax.jdo.option.ConnectionPassword","password");
PersistenceManagerFactory pmf = JDOHelper.getPersistenceManagerFactory(properties);
A slight variation on this, is to use a file ("jdo.properties" for example) to specify these
properties like this
javax.jdo.PersistenceManagerFactoryClass={my_implementation_pmf_class}
javax.jdo.option.ConnectionDriverName=com.mysql.jdbc.Driver
javax.jdo.option.ConnectionURL=jdbc:mysql://localhost/myDB
javax.jdo.option.ConnectionUserName=login
javax.jdo.option.ConnectionPassword=password
and then to create the PersistenceManagerFactory using this file
PersistenceManagerFactory pmf = JDOHelper.getPersistenceManagerFactory("jdo.properties");
A final alternative would be to call
JDOHelper.getPersistenceManagerFactory(jndiLocation, context);, hence
accessing the properties via JNDI.
Whichever way we wish to obtain the PersistenceManagerFactory we have defined a
series of properties to give the behaviour of the PersistenceManagerFactory.
The first property specifies to use PMF of the implementation required to be used,
and the following 4 properties define the datastore that it should connect to.
Standard JDO Properties
|
javax.jdo.PersistenceManagerFactoryClass
|
| Description |
The name of the PersistenceManager implementation |
|
javax.jdo.option.ConnectionFactory
|
| Description |
Instance of a connection factory. For RBDMS, it must be an instance of
javax.sql.DataSource. This is for a transactional DataSource |
|
javax.jdo.option.ConnectionFactory2
|
| Description |
Instance of a connection factory. For RBDMS, it must be an instance of
javax.sql.DataSource. This is for a non-transactional DataSource |
|
javax.jdo.option.ConnectionFactoryName
|
| Description |
The JNDI name for a connection factory. For RBDMS, it must be a JNDI name
that points to a javax.sql.DataSource object.
This is for a transactional DataSource |
|
javax.jdo.option.ConnectionFactory2Name
|
| Description |
The JNDI name for a connection factory. For RBDMS, it must be a JNDI name
that points to a javax.sql.DataSource object.
This is for a non-transactional DataSource |
|
javax.jdo.option.ConnectionDriverName
|
| Description |
The name of the driver to use for the DB |
|
javax.jdo.option.ConnectionDriverURL
|
| Description |
URL specifying the datastore to use for persistence |
|
javax.jdo.option.ConnectionUserName
|
| Description |
Username to use for connecting to the DB |
|
javax.jdo.option.ConnectionPassword
|
| Description |
Password to use for connecting to the DB |
|
javax.jdo.option.IgnoreCache
|
| Description |
Whether to ignore the cache for queries |
| Range of Values |
true | false |
|
javax.jdo.option.Multithreaded
|
| Description |
Whether to run the PersistenceManager multithreaded |
| Range of Values |
true | false |
|
javax.jdo.option.NontransactionalRead
|
| Description |
Whether to allow nontransactional reads |
| Range of Values |
true | false |
|
javax.jdo.option.NontransactionalWrite
|
| Description |
Whether to allow nontransactional writes |
| Range of Values |
true | false |
|
javax.jdo.option.Optimistic
|
| Description |
Whether to use Optimistic transactions |
| Range of Values |
true | false |
|
javax.jdo.option.RetainValues
|
| Description |
Whether to suppress the clearing of values from persistent instances on transaction
completion |
| Range of Values |
true | false |
|
javax.jdo.option.RestoreValues
|
| Description |
Whether persistent object have transactional field values restored when
transaction rollback occurs. |
| Range of Values |
true | false |
|
javax.jdo.option.Mapping
|
| Description |
Name for the ORM MetaData mapping files to use with this PMF. For example if this is set to
"mysql" then the implementation looks for MetaData mapping files called
"{classname}-mysql.orm" or "package-mysql.orm". If this is not specified then the JDO
implementation assumes that all is specified in the JDO MetaData file.
ORM datastores only |
|
javax.jdo.mapping.Catalog
|
| Description |
Name of the catalog to use by default for all classes persisted using this PMF.
This can be overridden in the MetaData where required, and is optional.
JPOX will prefix all table names with this catalog name if the RDBMS supports specification
of catalog names in DDL.
ORM datastores only |
|
javax.jdo.mapping.Schema
|
| Description |
Name of the schema to use by default for all classes persisted using this PMF.
This can be overridden in the MetaData where required, and is optional.
JPOX will prefix all table names with this schema name if the RDBMS supports specification
of schema names in DDL.
ORM datastores only |
| javax.jdo.option.DetachAllOnCommit |
| Description |
Allows the user to select that when a transaction is committed all objects
enlisted in that transaction will be automatically detached. |
| Range of Values |
true | false |
| javax.jdo.option.CopyOnAttach |
| Description |
Whether, when attaching a detached object, we create an attached copy or simply
migrate the detached object to attached state. This is from JDO 2.1 |
| Range of Values |
true | false |
| javax.jdo.option.TransactionType |
| Description |
Type of transaction to use. If running under J2SE the default is RESOURCE_LOCAL, and
if running under J2EE the default is JTA. |
| Range of Values |
RESOURCE_LOCAL | JTA |
| javax.jdo.option.PersistenceUnitName |
| Description |
Name of the "persistence-unit" to use with this PMF. This borrows the
"persistence-unit" concept from JPA for use with JDO 2.1. |
| javax.jdo.option.ServerTimeZoneID |
| Description |
Id of the TimeZone under which the datastore server is running.
If this is not specified or is set to null it is assumed that the datastore server
is running in the same timezone as the JVM under which the implementation is running. |
| javax.jdo.option.Name |
| Description |
Name of the PMF. This is for use with "named PMF" functionality in JDO 2.1 |
| javax.jdo.option.ReadOnly |
| Description |
Whether this datastore should be treated as read only. Added in JDO 2.2 |
| Range of Values |
true | false |
| javax.jdo.option.TransactionIsolationLevel |
| Description |
Isolation level to use for connections in the current transaction. Added in JDO 2.2 |
| Range of Values |
none | read-committed | read-uncommitted | repeatable-read | snapshot | serializable |
