What is the Spring 5 JDBC approach when nativeJdbc

I have just upgraded Spring/SpringBoot dependencies and noticed that class JdbcTemplate does not have property "nativeJdbcExtractor" any more.

I was able to find the details and background: https://jira.spring.io/browse/SPR-14670

However I was not able to find the replacement configuration. I use commons-dbcp library and Spring classes like SimpleJdbcCall etc. I never deal with low level JDBC API, however if the vendor code needs its real Connection type (Oracle) the nativeJdbcExtractor settings ensured it will get it somewhere deep in Spring JDBC code (not my app. code). I´m not sure how I can address this by calling connection.unwrap() if I need Spring API to handle this automatically as it did it in past.

java.lang.ClassCastException: org.apache.commons.dbcp2.PoolingDataSource$PoolGuardConnectionWrapper cannot be cast to oracle.jdbc.OracleConnection

Is that hidden somewhere in DataSource configuration? I have upgraded from commons-dbcp 1.4 to commons-dbcp2 but cannot find anything useful so far (BasicDataSource).

Update: Following thread is relevant but I cannot digest the answer I´m looking for since the Connection object is obtained within JdbcTemplate class and thus out of my control.

replacement for jdbc.support.nativejdbc remove in Spring 5

Update #2 - Stack Trace

Caused by: java.lang.ClassCastException: org.apache.commons.dbcp2.PoolingDataSource$PoolGuardConnectionWrapper cannot be cast to oracle.jdbc.OracleConnection
at oracle.sql.TypeDescriptor.setPhysicalConnectionOf(TypeDescriptor.java:832)
at oracle.sql.TypeDescriptor.<init>(TypeDescriptor.java:586)
at oracle.sql.ArrayDescriptor.<init>(ArrayDescriptor.java:224)
at org.springframework.data.jdbc.support.oracle.SqlArrayValue.createTypeValue(SqlArrayValue.java:90)
at org.springframework.jdbc.core.support.AbstractSqlTypeValue.setTypeValue(AbstractSqlTypeValue.java:60)
at org.springframework.jdbc.core.StatementCreatorUtils.setValue(StatementCreatorUtils.java:293)
at org.springframework.jdbc.core.StatementCreatorUtils.setParameterValueInternal(StatementCreatorUtils.java:232)
at org.springframework.jdbc.core.StatementCreatorUtils.setParameterValue(StatementCreatorUtils.java:147)
at org.springframework.jdbc.core.CallableStatementCreatorFactory$CallableStatementCreatorImpl.createCallableStatement(CallableStatementCreatorFactory.java:200)
at org.springframework.jdbc.core.JdbcTemplate.execute(JdbcTemplate.java:1048)
at org.springframework.jdbc.core.JdbcTemplate.call(JdbcTemplate.java:1104)
at org.springframework.jdbc.core.simple.AbstractJdbcCall.executeCallInternal(AbstractJdbcCall.java:414)
at org.springframework.jdbc.core.simple.AbstractJdbcCall.doExecute(AbstractJdbcCall.java:397)
at org.springframework.jdbc.core.simple.SimpleJdbcCall.execute(SimpleJdbcCall.java:193)

Update #3 - the code doing the cast (Oracle JDBC)

    public void setPhysicalConnectionOf(Connection var1) {
    this.connection = ((oracle.jdbc.OracleConnection)var1).physicalConnectionWithin();
}

New:

It looks like you're using org.springframework.data.jdbc.support.oracle.SqlArrayValue from spring-data-jdbc-ext. The bug is there and the unwrapping should happen there.

Something like the following (untested)

protected Object createTypeValue(Connection conn, int sqlType, String typeName)
        throws SQLException { 
    return conn.unwrap(OracleConnection.class).createArray(typeName, values);
}

Regarding the JDBC driver:

You are using Java 8 or later since Spring 5 requires Java 8. Therefore you should use ojdbc8 (8 means Java 8). I strongly recommend using the latest 12.2.0.1 driver from http://www.oracle.com/technetwork/database/application-development/jdbc/downloads/index.html.

If you check the driver interoperability matrix from http://www.oracle.com/technetwork/database/enterprise-edition/jdbc-faq-090281.html#01_02 you will see that this diver also works with older databases.

Old/Outdated:

In your code that performs the cast instead of casting call #unwrap. So instead of

OracleConnection oracleConnection = (OracleConnection) connection;

call

OracleConnection oracleConnection = connection.unwrap(OracleConnection.class);

In the stack trace you see who is doing the cast, this will be in your code because SimpleJdbcCall and friends don't case to OracleConnection. The issue is not in JdbcTemplate but your code doing the cast.