WebLogic provides an Ant task called wlconfig that can be used to change lots of settings in the WLS configuration. For example, you can create a JDBC connection pool and data source like this:
<wlconfig url="t3://localhost:7001" username="weblogic" password="weblogic">
<query domain="mydomain81" type="Server" name="myserver81" property="server-jmx-name"/>
<query type="JDBCConnectionPool" name="ZotPool">
<delete/> <!-- does nothing if the pool does not exist -->
</query>
<create type="JDBCConnectionPool" name="ZotPool">
<set attribute="DriverName" value="weblogic.jdbcx.oracle.OracleDataSource"/>
<set attribute="URL" value="jdbc:bea:oracle://mm1:1521"/>
<set attribute="Properties" value="serverName=mm1;SID=dev1;portNumber=1521;user=myuserid"/>
<set attribute="Password" value="mypassword"/>
<set attribute="ShrinkingEnabled" value="true"/>
<set attribute="InitialCapacity" value="0"/>
<set attribute="TestConnectionsOnReserve" value="true"/>
<set attribute="TestTableName" value="SQL SELECT 1 FROM DUAL"/>
<set attribute="Targets" value="${server-jmx-name}"/> <!-- must be the last attribute -->
</create>
<query type="JDBCTxDataSource" name="ZotDataSource">
<delete/> <!-- does nothing if the data source does not exist -->
</query>
<create type="JDBCTxDataSource" name="ZotDataSource">
<set attribute="JNDIName" value="ZotDataSource"/>
<set attribute="PoolName" value="ZotPool"/>
<set attribute="Targets" value="${server-jmx-name}"/>
</create>
</weblogic8x.wlconfig>