The classes and interfaces used in this specification come from the following packages:

javax.sql
java.sql

These packages have no associated version. It is assumed they come from the runtime environment. This specification is based on Java SE 1.4 or later.

A JDBC Database Driver is the software that maps the JDBC specification to a specific implementation of a relational database. For OSGi, JDBC drivers are delivered as driver bundles. A driver bundle registers a Data Source Factory service when it is ACTIVE. Service properties are used to specify the database driver name, version, etc. The Data Source Factory service provides methods to create DataSource, ConnectionPoolDataSource, XADataSource, or Driver objects. These objects are then used by an application to interact with the relational database system in the standard way.

The application can query the service registry for available Data Source Factory services. It can select particular drivers by filtering on the service properties. This service based model is easy to use with dependency injection frameworks like Blueprint or Declarative Services.

A Data Source Factory service should be registered while its Driver Bundle is in the ACTIVE state or when it has a lazy activation policy and is in the STARTING state.

What happens to the objects created by the Data Source Factory service, and the objects they created, is undefined in this specification. Database Drivers are not mandated to track the proper life cycle of these objects.

A Database Driver must import the javax.sql package. The java.sql package that contains the Driver and SQLException interface is automatically visible because it starts with java.. Both packages are contained in the JRE since Java SE 1.4. These packages are not normally versioned with OSGi version numbers. Bundles using the Data Source Factory must therefore ensure they get the proper imports, which is usually from the JRE. Due to the lack of specified metadata, the deployer is responsible for ensuring this.

Applications can query the OSGi service registry for available Database Drivers by getting a list of Data Source Factory services. Normally, the application needs access to specific drivers that match their needed relational database type. The service properties can be used to find the desired Database Driver. This model is well supported by dependency injection frameworks like Blueprint or Declarative Services. However, it can of course also be used with the basic service methods. The following code shows how a Service Tracker can be used to get a Database Driver called ACME DB.

Filter filter = context.createFilter(
    "(&(objectClass="  + 
        DataSourceFactory.class.getName() + 
    ")(" + 
        DataSourceFactory.OSGI_JDBC_DRIVER_CLASS + "=com.acme.db.Driver))");

ServiceTracker tracker = new ServiceTracker(context, filter, null);
tracker.open();

DataSourceFactory dsf = (DataSourceFactory) tracker.getService();

The Data Source Factory service can be used to obtain instances for the following JDBC related types:

Which type of Connection provider that is actually required depends on the Application and the use case. For each type, the Data Source Factory service provides a method that returns the corresponding instance. Each method takes a Properties object as a parameter to pass a configuration to the Database Driver implementation. The configuration is driver-specific and can be used to specify the URL for the database and user credentials. Common property names for these configuration properties are also defined in the DataSourceFactory interface.

A Data Source Factory is not required to implement all of the factory methods. If an implementation does not support a particular type then it must throw a SQL Exception. This specification does not provide a mechanism to depend on a Data Source Factory service that implements a particular factory method.

The following code shows how a DataSource object could be created.

Properties props = new Properties(); 
props.put(DataSourceFactory.JDBC_URL,      "jdbc:acme:ACMEDB"); 
props.put(DataSourceFactory.JDBC_USER,     "foo"); 
props.put(DataSourceFactory.JDBC_PASSWORD, "secret"); 
DataSource dataSource = dsf.createDataSource(props);

The DataSourceFactory interface has several static fields that represent common property keys for the Properties instance. General properties are:

The following additional property keys are provided for applications that want to create a ConnectionPoolDataSource object or a XAPoolDataSource object:

Which property keys and values are supported depends on the driver implementation. Drivers can support additional custom configuration properties.

The JDBC service provides JDBC driver services, not container services. A typical client would only use the DataSourceFactory.createDataSource() method to procure a regular Data Source from which they can obtain (usually non-pooled) connections.

Containers generally offer connection pools and support XA transactions. The container manages the pools and does this by using Pooled Connection or XA Connection objects from a driver-implemented respective Connection Pool Data Source or XA Data Source. To support containers, frameworks, or any client that wants to manage a pool, these Data Source types are included in the Data Source Factory service. Drivers are permitted to implement their own Data Source using an underlying connection pooling scheme. This is driver-dependent and not related to the OSGi specifications.

The usual set of JDBC properties are defined in the services for use with the Data Source types. They are the same as what is defined for JDBC and the caller should know which properties make sense when passed to a given Data Source type. The same result should occur in OSGi as occurs outside of OSGi. If the driver does not support a given property with a given Data Source type then it can ignore it or it can throw an Exception.