Pretty much what it says in the title, how the hell is this supposed to be done?

Basically i need to pass a null (empty?) ref cursor as an IN parameter to a stored procedure.

/** spring's PreparedStatementSetter#setValues(...) */
public void setValues(PreparedStatement ps) throws SQLException {
    CallableStatement cs = (CallableStatement) ps;
    cs.setString(1,"constant");
    //this is the IN param
    cs.setNull(2, OracleTypes.CURSOR);
    //this is the OUT param
    cs.registerOutParameter(3, OracleTypes.CURSOR);
}

And this fails with:

caused by: java.sql.SQLException: Unsupported feature: sqlType=-10
    at oracle.jdbc.driver.DatabaseError.throwSqlException(DatabaseError.java:112)
    at oracle.jdbc.driver.DatabaseError.throwSqlException(DatabaseError.java:146)
    at oracle.jdbc.driver.OraclePreparedStatement.setNullCritical(OraclePreparedStatement.java:4399)
    at oracle.jdbc.driver.OraclePreparedStatement.setNullInternal(OraclePreparedStatement.java:4161)
    at oracle.jdbc.driver.OracleCallableStatement.setNull(OracleCallableStatement.java:4472)

I'm at a loss here, tried several different ways to do this, but I couldn't find any examples about this and have no idea how to do it properly.