java web数据库连接封装-simple

package cn.cslg.bm.web.util;import java.sql.Connection;import java.sql.DriverManager;import org.apache.log4j.Logger;/** * 返回数据库连接 * @author husky * 未使用 */public class DBSimpleUtil {    private static Logger logger = Logger.getLogger(DBSimpleUtil.class);    public static String URL="jdbc:mysql://******:3306/bm?characterEncoding=UTF-8";    public static String USER="*****";    public static String PASS="******";    public static Connection conn=null;    static {        try {            Class.forName("com.mysql.jdbc.Driver");        } catch (ClassNotFoundException e) {            e.printStackTrace();        }    }    public static Connection openConnection(){        System.out.println("test");        try{            if(conn==null||conn.isClosed())                logger.info("打开数据库！");                conn=DriverManager.getConnection(URL, USER, PASS);        }catch(Exception e){            logger.error("打开数据库出错！");            e.printStackTrace();        }        return conn;    }    public static void closeConnection(){        try{            if(conn!=null&&!conn.isClosed()){                logger.info("关闭数据库！");                conn.close();            }        }catch(Exception e){            logger.error("关闭数据库出错！");            e.printStackTrace();        }    }//    public static void main(String[] args) {//        DBSimpleUtil.openConnection();//        DBSimpleUtil.closeConnection();//    }}