使用mysql（6部曲）
使用properties文件配置数据库驱动，uri，用户名和密码；以便于日后更换数据库不用更改源代码；
driver=com.mysql.jdbc.Driver uri=jdbc:mysql://localhost:3306/day10 user=root password=root
1.注册驱动
1 public static Connection getConn() throws FileNotFoundException, IOException, ClassNotFoundException, SQLException{ 2 3 Class.forName(prop.getProperty("driver")); 4 return DriverManager.getConnection(prop.getProperty("uri"),prop.getProperty("user"),prop.getProperty("password")); 5 6 7 }
2.创建连接器
Connection conn = JDBCUtils.getConn(); //Connection conn = DriverMananger("uri,user,password");
3.获取传输器
Statment stat = conn.createStatement();
5.利用传输器查询语句，并返回结果集
stat.executeUpdate(sql); 增删改
stat.executeQuery(sql);查询语句
6.关闭资源
1 public static void close(Connection conn,Statement stat,ResultSet rs){ 2 3 if(rs!=null){ 4 try { 5 rs.close(); 6 } catch (SQLException e) { 7 throw new RuntimeException(e); 8 9 }finally{ 10 rs=null; 11 } 12 } 13 if(stat!=null){ 14 try { 15 stat.close(); 16 } catch (SQLException e) { 17 throw new RuntimeException(e); 18 19 }finally{ 20 stat=null; 21 } 22 } 23 if(conn!=null){ 24 try { 25 conn.close(); 26 } catch (SQLException e) { 27 throw new RuntimeException(e); 28 29 }finally{ 30 conn=null; 31 } 32 } 33 }
最后 使用预编译语句可防止SQL语句的注入问题，preparestatment
1 String sql = "select * from user where username=?and password =?"; 2 ps = conn.prepareStatement(sql); 3 ps.setString(1, username); 4 ps.setString(2, password); 5 rs = ps.executeQuery();
