Revert "Oracle refactoring work" (#448)

This reverts commit a716c77.

Author: MrRahulSharma

database-commons/src/main/java/io/cdap/plugin/db/source/AbstractDBSource.java

@@ -146,7 +146,7 @@ public Schema getSchema(Class<? extends Driver> driverClass) throws IllegalAcces
     }
   }
 
-  public Schema loadSchemaFromDB(Connection connection, String query) throws SQLException {
+  private Schema loadSchemaFromDB(Connection connection, String query) throws SQLException {
     Statement statement = connection.createStatement();
     statement.setMaxRows(1);
     if (query.contains("$CONDITIONS")) {

database-commons/src/main/java/io/cdap/plugin/util/DriverCleanup.java

@@ -28,7 +28,7 @@
  * class to de-register driver
  */
 public class DriverCleanup implements Destroyable {
-  public final JDBCDriverShim driverShim;
+  private final JDBCDriverShim driverShim;
 
   DriverCleanup(@Nullable JDBCDriverShim driverShim) {
     this.driverShim = driverShim;

oracle-plugin/src/main/java/io/cdap/plugin/oracle/OracleSource.java

@@ -103,21 +103,6 @@ public static class OracleSourceConfig extends AbstractDBSpecificSourceConfig {
     @Description("The existing connection to use.")
     private OracleConnectorConfig connection;
 
-    @Name(OracleConstants.ROLE)
-    @Description("Login role of the user when connecting to the database.")
-    @Nullable
-    private String role;
-
-    @Name(OracleConstants.NAME_DATABASE)
-    @Description("SID or Service Name to connect to")
-    @Nullable
-    private String database;
-
-    @Name(OracleConstants.TRANSACTION_ISOLATION_LEVEL)
-    @Description("The transaction isolation level for the database session.")
-    @Nullable
-    private String transactionIsolationLevel;
-
     @Name(OracleConstants.DEFAULT_BATCH_VALUE)
     @Description("The default batch value that triggers an execution request.")
     @Nullable
@@ -128,18 +113,6 @@ public static class OracleSourceConfig extends AbstractDBSpecificSourceConfig {
     @Nullable
     private Integer defaultRowPrefetch;
 
-    public OracleSourceConfig(String host, int port, String user, String password, String jdbcPluginName,
-                              String connectionArguments, String connectionType, String role, String database,
-                              String transactionIsolationLevel, int defaultBatchValue, int defaultRowPrefetch) {
-      this.connection = new OracleConnectorConfig(host, port, user, password, jdbcPluginName, connectionArguments,
-                                                  connectionType);
-      this.role = role;
-      this.database = database;
-      this.transactionIsolationLevel = transactionIsolationLevel;
-      this.defaultBatchValue = defaultBatchValue;
-      this.defaultRowPrefetch = defaultRowPrefetch;
-    }
-
     @Override
     public String getConnectionString() {
       if (OracleConstants.TNS_CONNECTION_TYPE.equals(connection.getConnectionType())) {