package com.foreknow.db;




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

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;

import com.foreknow.util.PropertyUtil;




public class DBManager {
    
    private Properties prop;
    private String path = "src/datainfo.properties";
    private PropertyUtil propertyUtil;
    private static DBManager dbManager = null;
    private Log logger = LogFactory.getLog(DBManager.class);
    
    //单例不能new
    private DBManager(){
    }
    
    public static DBManager getInstance() {
        if (dbManager == null) {
            dbManager = new DBManager();
        }
        return dbManager;
    }

    /**
     * @return
     * 与数据库进行连接
     */
    public Connection getConnection() {
        if (propertyUtil == null) {
            propertyUtil = PropertyUtil.getInstance();
            if (prop == null) {
                prop = propertyUtil.getProperty(path);
                if (logger.isInfoEnabled()) {
                    logger.info("读取数据库配置文件： " + path);
                }
            }
        }
        Connection conn = null;
        try {
            Class.forName(prop.getProperty("DRIVER"));//datainfo
            conn = DriverManager.getConnection(prop.getProperty("DBURL"),prop.getProperty("USERNAME"),prop.getProperty("USERPWD"));
            conn.setAutoCommit(false);//先这样简单自动提交，以后再业务层管理事务，就需要设置为false了
            if (logger.isInfoEnabled()) {
                logger.info("读取数据库配置文件成功！");
            }
        } catch (ClassNotFoundException e) {
            if (logger.isErrorEnabled()) {
                logger.error("找不到数据库驱动！");
            }
        } catch (SQLException e) {
            if (logger.isErrorEnabled()) {
                logger.error("连接失败！");
            }
        }
        return conn;
    }
}