package com.insit.intranet.common.db;
import java.sql.*;
import javax.sql.*;
import java.util.*;
import java.io.*;
import javax.naming.*;

/**
 * 獲得數據庫連接connection
 * @author ypb
 * 數據庫聯接池 = 工廠模式 + 單件模式的組合
 */
public class ConnectionFactory {
  private String driver = null;
  private String dbUrl = null;
  private String userName = null;
  private String password = null;
  private String contextFactory = null;
  private String serviceProvider= null;
  
  
  private static ConnectionFactory factory = null;

  synchronized public static ConnectionFactory getFactory() throws IOException {
      if (factory == null) {
         factory = new ConnectionFactory();
      }
      return factory;
  }

  private ConnectionFactory() throws IOException {
        init();
  }
  
  private void init(){ 
        InputStream is = getFileInputStream();
        Properties props = new Properties();
        try{
            props.load(is);      
            driver   = props.getProperty("driver_name");
            dbUrl    = props.getProperty("db_url");     
            userName = props.getProperty("user_name");
            password = props.getProperty("password");
            contextFactory = props.getProperty("context_factory");
            serviceProvider = props.getProperty("service_provide_url");
        }catch(Exception e){
            e.printStackTrace();
        }
    }
  
  private InputStream getFileInputStream() {
     
    InputStream is = getClass().getResourceAsStream("db_config.properties");
    return is;
  }

  public Connection getConnection() throws SQLException,ClassNotFoundException {
    
      Class.forName(driver);
    
      return DriverManager.getConnection(dbUrl, userName, password);
  }
 /**
  * 通過jndi獲取數據庫連接 
  * @param jndiName
  * @return
  * @throws NamingException
  * @throws SQLException
  */
 public Connection getConnection(String jndiName)throws NamingException,SQLException{
        Properties myProperties = new Properties();
        myProperties.setProperty(Context.INITIAL_CONTEXT_FACTORY,contextFactory);
        myProperties.setProperty(Context.PROVIDER_URL,serviceProvider);
        Context ctx = new InitialContext(myProperties);
        DataSource ds = (DataSource)ctx.lookup(jndiName);
        Connection conn = ds.getConnection();
        return conn;
    }

}