JDBC连接数据库（查询）

public class App {
    public static void main(String[] args) throws Exception {
        
        
        Class.forName("com.mysql.cj.jdbc.Driver");
        
        Connection conn = DriverManager.getConnection("jdbc:mysql://localhost:3306/vip?serverTimezone=GMT&useSSL=false", "root", "zhangpn");
        
        Statement stat = conn.createStatement();
        
        ResultSet res = stat.executeQuery("select * from sys_user");
        
        while(res.next()){
            System.out.println(res.getString(1)+"***"+res.getString(2)+"***"+res.getString(3)+"***"+res.getString(4));
        }
        
        res.close();
        stat.close();
        conn.close();
        
    }
}

1.加载启动：Class.forName("com.mysql.cj.jdbc.Driver");

2.获取连接：Connection conn = DriverManager.getConnection("jdbc:mysql://localhost:3306/vip?serverTimezone=GMT&useSSL=false", "root", "zhangpn");

3.创建语句对象：Statement stat = conn.createStatement();

4.执行SQL并获取数据：ResultSet res = stat.executeQuery("select * from sys_user");

5.处理数据：        while(res.next()){
            System.out.println(res.getString(1)+"***"+res.getString(2)+"***"+res.getString(3)+"***"+res.getString(4));
        }

6.关闭连接：close()