JDBCUtils工具类

JDBCUtils工具类

public class JDBAUtils {
    private static String url;
    private static String username;
    private static String password;
    private static String driver;
    //静态代码块，只执行一次
    static {
        //读取资源文件获取值
        try {
            //1.创建Properties集合类
            Properties pro = new Properties();
            
            //获取src路径下的文件方式-->ClassLoader 类加载器
            ClassLoader classLoader = JDBCUtils.class.getClassLoader();
            URL res = classLoader.getResource("jdbc.properties");
            String path = res.getPath();
            //2.加载文件
            pro.load(new FileRader(path));
            //3.获取数据，赋值
            url = pro.getProperty("url");
            username = pro.getProperty("username");
            password = pro.getProperty("password");
            driver = pro.getProperty("driver");
            //4.注册驱动
            Class.forName(driver);
        } catch (IOException e) {
            e.printStackTrace();
        }catch (Exception e) {
            // TODO: handle exception
            throw new IllegalArgumentException("非法异常");
        }
    }
    //获得数据库连接
    public static Connection getConn()throws SQLException{
        return DriverManager.getConnection(url,usename,password);
    }
    //数据关流
    public static void close(Connection conn,PreparedStatement ps,ResultSet rs){
        if(conn!=null){
            try {
                conn.close();
            } catch (SQLException e) {
                e.printStackTrace();
            }
        }
        if(ps!=null){
            try {
                ps.close();
            } catch (SQLException e) {
                e.printStackTrace();
            }
        }
        if(rs!=null){
            try {
                rs.close();
            } catch (SQLException e) {
                e.printStackTrace();
            }
        }
    }
    //数据关流重载
    public static void close(Connection conn,PreparedStatement ps){
        close(conn,ps,null);
    }
}