This has been a nail biting issues for me where I had to connect to an older unsupported version of oracle from a newer version of Weblogic.
An upgrade document on weblogic 10.3 states that 8.1.7 is no longer supported by weblogic.
http://download.oracle.com/docs/cd/E15919_01/wlp.1032/e14253/upgrade_process.htm
This is true as we will not be able to simply create a datasource from weblogic 10.3 to oracle 8.1.7
coz the driver (ojdbc6.ja and ojdbc5.jar) as packaged with weblogic are not compatible with the same.
Hence the search began to find a suitable driver. The Drivers as mentioned by oracle for 8.1.7 can be viewed here:
http://www.oracle.com/technology/software/tech/java/sqlj_jdbc/htdocs/jdbc817.html.
Of course I started off with downloading classes12.jar
and I realised that though my standalone unit tests(JUNIT 4 using spring AbstractTransactionalDataSourceSpringContextTests) worked fine with some tweaks here and there.
However when the same spring config
<bean id="testDataSource" class="org.springframework.jdbc.datasource.DriverManagerDataSource"> <property name="driverClassName"><value>oracle.driver.jdbc.OracleDriver</value></property> <property name="url"><value>jdbc:oracle:thin:@host:port:databasename</value></property> <property name="username"><value>USERNAME</value></property> <property name="password"><value>PASSWORD</value></property> </bean>
was used within an app deployed on weblogic to connect to the database I got a weird exception:
java.lang.ArrayIndexOutOfBoundsException: 4 at oracle.jdbc.driver.T4C8TTIdty.marshal(T4C8TTIdty.java:465) at oracle.jdbc.driver.T4CConnection.logon(T4CConnection.java:329) at oracle.jdbc.driver.PhysicalConnection.<init>(PhysicalConnection.java: 490) at oracle.jdbc.driver.T4CConnection.<init>(T4CConnection.java:202) at oracle.jdbc.driver.T4CDriverExtension.getConnection(T4CDriverExtensio n.java:33) at oracle.jdbc.driver.OracleDriver.connect(OracleDriver.java:474) at java.sql.DriverManager.getConnection(DriverManager.java:582) at java.sql.DriverManager.getConnection(DriverManager.java:185)
The problem was obvious Weblogic class loader was trying to return the Oracle Driver as present in ojdbc6.jar or ojdbc5.jar and completely ignored my classes12.jar which I had in the classpath.
Hence I had to start from scratch again. I instead added classes12.jar to the weblogic classpath and tried creating a datasource using the weblogic console , even then I gotthe
same exception as above. I wondered if upgrading to another jar would help. I hence downloaded ojdbc14.jar and added it to the weblogic classpath and tried creating a datasource
and it was successful.
However I wondered if there was away of not changing the weblogic classpath and instead using ojdbc14.jar from within my application to be loaded in preference as ooposed to
odjbc6.jar/ojdbc5.jar as present in weblogic classpath.
I later added
<container-descriptor>
<prefer-web-inf-classes>true</prefer-web-inf-classes>
</container-descriptor>
to my weblogic.xml so as to change the classloader preference.
Some forums suggested using the weblogic-application.xml to achieve the same by adding
<prefer-application-packages>
<package-name>oracle.jdbc.driver.*</package-name>
</prefer-application-packages>
Both will change the order for class loader preferences.
However for me the first option worked.
So now I am able to connect to oracle 8.1.7 from an application which has ojdbc14.jar in web-inf/lib and the weblogic.xml says to prefer the same.
The datasource is not a jndi datasource as can be done in weblogic but it is a spring configured datasource.
I guess this is a neater and an easier option for me as it saves me the task of upgrading to a newer oracle or downgrading to a older weblogic
