title: sealing violation: package oracle.jdbc.pool is sealed oracle UCP connection pooling
body: <p>My project was using <code>ojdbc6</code> with <code>c3p0</code> connection pooling . This i moved to <code>ojdbc8</code> and <code>UCP(Oracle's universal connection pooling)</code>. But i am getting below error:</p>
  
  <p><code>UCP Config</code> used:</p>
  
  <pre><code>try
                  {
                      //Creating a pool-enabled data source
                      pds= PoolDataSourceFactory.getPoolDataSource();
  
                      String dbURL="jdbc:oracle:thin:@(DESCRIPTION = (CONNECT_TIMEOUT= 15)(RETRY_COUNT=20)(RETRY_DELAY=3) (ADDRESS_LIST =(LOAD_BALANCE=on)(ADDRESS = (PROTOCOL = TCP) (HOST = vm-host-101) (PORT = 1521))) (CONNECT_DATA = (SERVER = DEDICATED) (SERVICE_NAME = S1NAME)))";
  
            //this is where am using that package 
                      pds.setConnectionFactoryClassName("oracle.jdbc.pool.OracleDataSource");
                      pds.setURL(dbURL);
                      pds.setUser("username");
                      pds.setPassword("password");
                      pds.setInitialPoolSize(5);
                      pds.setMinPoolSize(5);
                      pds.setMaxPoolSize(10);
                      pds.setFastConnectionFailoverEnabled(false);
                      return pds;
                  }
                  catch(SQLException e)
                  {
                      e.printStackTrace();
                  }
                  return pds;
  
              }
  </code></pre>
  
  <p>Error:</p>
  
  <pre><code>Caused by: java.sql.SQLException: Unable to create factory class instance with provided factory class name: java.lang.SecurityException: sealing violation: package oracle.jdbc.pool is sealed
      at oracle.ucp.util.UCPErrorHandler.newSQLException(UCPErrorHandler.java:456) ~[ucp-12.2.0.1.jar:12.2.0.1.0]
      at oracle.ucp.util.UCPErrorHandler.throwSQLException(UCPErrorHandler.java:133) ~[ucp-12.2.0.1.jar:12.2.0.1.0]
      at oracle.ucp.jdbc.PoolDataSourceImpl.initConnectionFactory(PoolDataSourceImpl.java:3243) ~[ucp-12.2.0.1.jar:12.2.0.1.0]
      at oracle.ucp.jdbc.PoolDataSourceImpl.createUniversalConnectionPool(PoolDataSourceImpl.java:1105) ~[ucp-12.2.0.1.jar:12.2.0.1.0]
      ... 61 common frames omitted
  Caused by: java.lang.SecurityException: sealing violation: package oracle.jdbc.pool is sealed
  </code></pre>
  
  <p>I understand the error will come when we have 2 <code>class</code> loaded from same <code>package</code>. But i checked in external dependencies in <code>intellij</code> and also tried <code>mvn dependency:tree</code> command of <code>maven</code>. I couldn't find duplicate <code>OJDBC jars</code> in <code>classpath</code>.</p>
  
  <p>Is there any other reason for this?</p>