In my project[1] I am using a derby in-memory database with the embedded
driver for unit testing and integration testing. I am using PostgreSQL
as the production server.
I am using Liquibase[2] to set up the schema for both Derby and
PostgreSQL, and I'm also using Liquibase to set up the test data in the
derby database.
What I wanted to do, was to dump the test database to a Derby network
server and do some tests on the data. My changes worked fine in
PostgreSQL but not in the derby tests, and I wanted the chance to take a
look at them.
So what I did was add a pseudo unit test to a test class, that would
connect to "jdbc:derby://localhost:1527/ukelonn"[3].
When I tried running that test, it was unable to find the driver.
So I googled a bit more, and added a dependency to the derby client
jar in the test scope[4].
But then the unit test failed with the following error:
java.lang.ClassCastException: org.apache.derby.jdbc.ClientDriver cannot be
cast to org.apache.derby.jdbc.InternalDriver
at org.apache.derby.jdbc.BasicEmbeddedDataSource40.findDriver(Unknown
Source)
at
org.apache.derby.jdbc.EmbeddedConnectionPoolDataSource.createPooledConnection(Unknown
Source)
at
org.apache.derby.jdbc.EmbeddedConnectionPoolDataSource.getPooledConnection(Unknown
Source)
at
no.priv.bang.ukelonn.bundle.db.test.UkelonnDatabaseProviderTest.addUkelonnSchemaAndDataToDerbyServer(UkelonnDatabaseProviderTest.java:296)
Are the problems caused by me having both the embedded driver and the
network driver loaded into the same java application (in this case: the
same JUnit test)?
If there is a conflict between the embedded JDBC driver and the client
JDBC driver, is there a way around the conflict, other than creating a
separate maven project just to upload the liquibase files?
Thanks!
- Steinar
References:
[1] <https://github.com/steinarb/ukelonn>
[2] <http://www.liquibase.org>
[3]
<https://github.com/steinarb/ukelonn/blob/scratch/derby-test-writing-to-network-server/ukelonn.bundle.db.test/src/test/java/no/priv/bang/ukelonn/bundle/db/test/UkelonnDatabaseProviderTest.java#L283>
[4]
<https://github.com/steinarb/ukelonn/commit/513d94690bd86cd42116190e2b58ce2a71fb80e6>
