使用idea开发Servlet详细图文教程

public void service(ServletRequest request, ServletResponse response) throws ServletException, IOException {

        response.setContentType("text/html");
        PrintWriter out = response.getWriter();
        Connection conn = null;
        PreparedStatement ps = null;
        //同步替换变量名shift+F6
        ResultSet rs = null;
        try{
            //1.注册驱动的第二种方式：类加载注册
            Class.forName("com.mysql.cj.jdbc.Driver");//可以写到配置文件当中
//            Class.forName(driver);
            //2.获取连接
            conn = DriverManager.getConnection("jdbc:mysql://localhost:3306/trade_for_book","root","002415");
//            conn = DriverManager.getConnection(url,user,password);
            //3.获取数据库操作对象
            String sql = "select * from store";
            ps = conn.prepareStatement(sql);
//            4.执行sql语句
            rs = ps.executeQuery();
//            5.处理数据集
            while (rs.next()) {
                String name = rs.getString("name");
                out.print("name" + name+"<br>");
            }
        }catch(Exception e){
            e.printStackTrace();

        }finally {
            if (rs != null){
                try{
                    rs.close();
                }catch(SQLException e){
                    e.printStackTrace();
                }
            }

            if (ps != null){
                try{
                    ps.close();
                }catch(SQLException e){
                    e.printStackTrace();
                }
            }

            if (conn != null){
                try{
                    conn.close();
                }catch(SQLException e){
                    e.printStackTrace();
                }
            }
        }
    }