import java.sql.Connection;

public interface ServerConnector
{
	Connection getConnection();
	String getConnectionURL();
	String getConnectionDetails();
	String getTablesSchemaQuery();
	String getDBName();
	String getServername();
	String getUserName();
}
------------

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.SQLException;



public class OracleServerConnector implements ServerConnector {
	private final String servidor ="jdbc:oracle:thin:@localhost:1521:xe";
	private String user= null;
	private String password=null;

	public OracleServerConnector(){}

	public OracleServerConnector(String user, String password)
	{
		this.user = user;
		this.password = password;
		try {
			DriverManager.registerDriver (new oracle.jdbc.driver.OracleDriver());


		} catch (SQLException e) {

			// TODO Auto-generated catch block
			e.printStackTrace();
		}
	}


	@Override
	public Connection getConnection() {
		Connection conn = null;
		try {
			conn = DriverManager.getConnection
			          (servidor, user, password);
		} catch (SQLException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
		return conn;
	}

	@Override
	public String getConnectionURL() {
		return String.format("Conexion a ORACLEdb : %s como %s identificado por %s", servidor, user, password);
	}

	@Override
	public String getConnectionDetails() {
		String texto= "Nada que ver aqui";
		return texto;
	}

	@Override
	public String getTablesSchemaQuery() {
		return String.format("select * from user_tables");

	}

	@Override
	public String getDBName() {
		return user;
	}

	@Override
	public String getServername() {

		return servidor;
	}

	@Override
	public String getUserName() {
		return user;

	}

}
---------------

import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;

public class Manager {
	Connection con = null;
	ServerConnector scb = null;
	public Manager(){}

	public Manager(ServerConnector con)
	{
		this.scb = con;
	}
	public boolean setConnectionBehavior(ServerConnector connector)
	{
		if (connector == null)
		{
			throw new IllegalArgumentException("Server Connector cannot be null!");
		}
		scb = connector;
		return true;
	}
	public boolean openConnection()
	{
		try
		{
			if (scb == null) throw new IllegalStateException ("Cannot open connection without a defined connection behavior!");

			if (con != null) closeConnection(false);
			con = scb.getConnection();
		}
		catch (Exception ex)
		{

			ex.printStackTrace();
			return false;
		}

		if (con == null) return false;
		return true;
	}
	public boolean closeConnection(boolean keepAlive)
	{
		try
		{
			//if not null and open
			if (con != null)
			{
				if (!con.isClosed())
				{
					//close it
					con.close();
				}
			}
			if (!keepAlive)
			{
				con = null;
			}
		}
		catch (Exception ex)
		{

			ex.printStackTrace();
			return false;
		}
		return true;
	}
	public boolean isConnected()
	{
		return con != null;
	}
	public boolean ExecuteNonQuery(String query)
	{
		try
		{
			Statement st = null;
			st = con.createStatement();
			int i = st.executeUpdate(query);
			if (i == -1){
				System.out.println("db error : " + query);
				return false;
			}
			st.close();
		}
		catch (Exception ex)
		{

			ex.printStackTrace();
			return false;
		}
		return true;
	}
	public ResultSet ExecuteQuery(String query)
	{
		ResultSet rs = null;
		try {
			Statement stmt = con.createStatement();
			rs = stmt.executeQuery(query);
		} catch (SQLException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}

		return rs;

	}

	public ResultSet ExecuteRSGetTableSchema()
	{
		try
		{
			PreparedStatement pst = con.prepareStatement(GetTablesSchemaQuery());
			return pst.executeQuery();
		}
		catch (SQLException e)
		{
			// TODO Add better logging
			e.printStackTrace();
		}
		return null;
	}
	public Connection GetConnection()
	{
		return con;
	}
	public String GetConnectionURL()
	{
		return scb.getConnectionURL();
	}
	public String GetTablesSchemaQuery()
	{
		return scb.getTablesSchemaQuery();
	}
	public String GetDBName()
	{
		return scb.getDBName();
	}

	/**
	 * Get the name of the server.
	 * @return name of the server.
	 */
	public String GetServerName()
	{
		return scb.getServername();
	}

	/**
	 * Get the name of the user.
	 * @return name of the user.
	 */
	public String GetUserName()
	{
		return scb.getUserName();
	}
}