/*
 * GenericDAO.java
 *
 * Created on 2 de Dezembro de 2006, 03:50
 *
 * To change this template, choose Tools | Template Manager
 * and open the template in the editor.
 */

package com.tecgraf.dao;

import com.tecgraf.dao.DAOException;
import java.io.Serializable;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;

/**
 *
 * @author ismael
 */
public abstract class GenericDAO<T, ID extends Serializable> implements IGenericDAO<T, ID> {
  private String driverClass;
  private String dbURL;
  private String dbName;
  private String user;
  private String passwd;
  
  protected Connection con = null;
  protected PreparedStatement ps;
  protected ResultSet rs;
  
  /** Creates a new instance of GenericDAO */
  public GenericDAO() {
    this.driverClass = "org.postgresql.Driver";
    this.dbURL = "jdbc:postgresql:";
    this.dbName = "postgres";
    this.user = "postgres";
    this.passwd = "postgres";
  }
  
  public GenericDAO(String dataBase, String dbName, 
                    String user, String passwd ) {
    
    if( dataBase.equalsIgnoreCase("postgresql") ) {
      driverClass = "org.postgresql.Driver";
      dbURL = "jdbc:postgresql:";    
    }
    else if ( dataBase.equalsIgnoreCase("mysql") ) {
      driverClass = "org.gjt.mm.mysql.Driver";
      dbURL = "jdbc:mysql:";
    }
    else if ( dataBase.equalsIgnoreCase("jdbcodbc") ) {
      driverClass = "sun.jdbc.odbc.JdbcOdbcDriver";
      dbURL = "jdbc:odbc:";
    }
      
    this.dbName = dbName;
    this.user = user;
    this.passwd = passwd;
  }
  
  private void getConnection() throws DAOException {
    if( con != null )
      return;
    
    try {
      Class.forName(driverClass);   // "org.postgresql.Driver"
      String url = dbURL + dbName;  // "jdbc:postgresql:" + "postgres"
      con = DriverManager.getConnection(url, user, passwd);
    } catch (ClassNotFoundException ex) {
      throw new DAOException("SQL exception in getConnection", ex);
    } catch (SQLException ex) {
      throw new DAOException("SQL exception in getConnection" , ex);
    }
  }
  
  
  public void closeConnection() throws DAOException {
    try {
      if (con!=null){
        con.close();
      }
      con = null;
    } catch (SQLException ex) {
      throw new DAOException("SQL exception in closeConnection" , ex);
    }
  }
  public void getPreparedStatement(String query) throws DAOException {
    try {
      getConnection();
      ps = con.prepareStatement(query);
    } catch (SQLException ex) {
      throw new DAOException("SQL exception in getPreparedStatement" , ex);
    }
  }
  
  public void closePreparedStatement() throws DAOException {
    try {
      ps.close();
      closeConnection();
    } catch (SQLException ex) {
      throw new DAOException("SQL exception in closePreparedStatement" , ex);
    }
  }
}