Creating DataSource Objects Dynamically

If you want to bind only a single DataSource object in the namespace to be used for multiple database resources, you must do the following:

1. Bind the DataSource without specifying the URL, host, port, SID, or driver type. Thus, you execute the bindds tool with only the -dstype jta option, as follows:

   sess_sh -service jdbc:oracle:thin:@nsHost:5521:ORCL -user SCOTT -password 
   TIGER
   & bindds /test/empDatabase -dstype jta
   
   

2. Retrieve the DataSource in your code. When you perform the lookup, you must cast the returned object to OracleJTADataSource instead of DataSource. The Oracle-specific version of the DataSource class contains methods to set the DataSource properties.

3. Set the following properties:
   • URL with the OracleJTADataSource.setURL method

   • Host, port, SID, and driver type if you did not set the URL with the following OracleJTADataSource methods: setURL, setDatabaseName, setPortNumber, and setDriverType

   • Database link if using two-phase commit engine with the OracleJTADataSource.setDBLink method

   • Username and password if need to provide authentication information for a two-phase commit engine. This information could have been provided on the initial context environment or can be provided in the getConnection method. However, if you want to set it with the OracleJTADataSource methods, you can through the setUser and setPassword methods.

4. Retrieve the connection through the OracleJTADataSource.getConnection method as indicated in the other examples.

Example 7-4 Retrieving Generic DataSource

The following example retrieves a generically bound DataSource from the namespace using in-session lookup and initializes all relevant fields.

//retrieve an in-session generic DataSource object
OracleJTADataSource ds = (OracleJTADataSource)ic.lookup ("/test/genericDS");

//set all relevant properties for my database
//URL is for a local database so use the KPRB URL
ds.setURL ("jdbc:oracle:kprb:");
//Used in two-phase commit, so provide the fully qualified database link that 
//was created from the two-phase commit engine to this database
ds.setDBLink("localDB.oracle.com");

//Finally, retrieve a connection to the local database using the DataSource
Connection conn = ds.getConnection ();

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