JDBC_数据库连接池工具类

 //定义一个类JDBCUtils
 public class JDBCUtils {
     //1.定义成员方法
     private static DataSource ds;
     //2.提供静态代码块
     static{
         //3.加载配置文件
         Properties pro = new Properties();
         try {
             pro.load(JDBCUtils.class.getClassLoader().getResourceAsStream("druid.properties"));
         } catch (IOException e) {
             e.printStackTrace();
         }
         //4.获取DataSource
         try {
             DataSource dataSource = DruidDataSourceFactory.createDataSource(pro);
         } catch (Exception e) {
             e.printStackTrace();
         }
     }
     //5.获取连接
     public static Connection getConnection() throws SQLException {
         return ds.getConnection();
     }
     // 6.释放资源
     public static void close(ResultSet re, Statement stmt,Connection conn) throws SQLException {
         if (re != null){
             re.close();
         }
         if (stmt != null){
             stmt.close();
         }
         if (conn != null) {
             conn.close();
         }
     }
 }