Desenvolvimento Web

import java.sql.DriverManager;
import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
import java.util.logging.Level;
import java.util.logging.Logger;

/**
 *
 * @author Samuel
 */
public abstract class GenericDAO {

	private static final long serialVersionUID = 1L;

	public Connection getConnection() {
		try {
			Class.forName("org.apache.derby.jdbc.ClientDriver");
			Connection cx = DriverManager.getConnection("jdbc:derby://localhost/petshop", "petshop", "petshop");
			return cx;
		} catch (Exception ex) {
			Logger.getLogger(GenericDAO.class.getName()).log(Level.SEVERE, null, ex);
			return null;
		}
	}

	public Statement getStatement() throws SQLException {
		return getConnection().createStatement();
	}

	public PreparedStatement getStatement(String st) throws SQLException {
		return getConnection().prepareStatement(st);
	}

	public ResultSet executeQuery(String query, Object... params) throws SQLException {
		PreparedStatement ps = getStatement(query);
		for (int i = 0; i < params.length; i++) {
			ps.setObject(i + 1, params[i]);
		}
		return ps.executeQuery();
	}

	public int executeCommand(String query, Object... params) throws SQLException {
		PreparedStatement ps = getStatement(query);
		for (int i = 0; i < params.length; i++) {
			try {
				ps.setObject(i + 1, params[i]);
			} catch (Exception e) {
				System.out.println("Error to try " + i + " white value " + params.toString());
			}

		}
		int result = ps.executeUpdate();
		ps.close();
		return result;
	}

}