JDBC工具类

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;

public class BaseDao {
    //驱动名称
    private static final String DRIVER = "com.mysql.cj.jdbc.Driver";
    //连接musql的路径
    private static final String URL = "jdbc:mysql://localhost:3306/test?serverTimezone=UTC &useUnicode=true&characterEncoding=UTF-8";
    //连接mysql的用户名
    private static final String USER = "root";
    //连接mysql的密码
    private static final String PASS_WORD = "root";

    public Connection getConnection() {//注册驱动，连接数据库
        try {
            Class.forName(DRIVER);//注册驱动
        } catch (ClassNotFoundException e) {
            e.printStackTrace();
        }
        Connection conn=null;
        try {
             conn=DriverManager.getConnection(URL, USER, PASS_WORD);//登陆用户
        } catch (SQLException e) {
            e.printStackTrace();
        }
        return conn;
    }
    
    private  void closedConnection(Connection con){//关闭Connection
        try {
            if(con!=null) {
                con.close();
            }
        } catch (SQLException e) {
            e.printStackTrace();
        }
    }
    private  void closedStatement (Statement stmt){//关闭Statment
        try {
            if(stmt!=null) {
                stmt.close();
            }
        } catch (SQLException e) {
            e.printStackTrace();
        }
    }
    private static void closedResultSet (ResultSet  rs){//关闭ResultSet
        try {
            if(rs!=null) {
                rs.close();
            }
        } catch (SQLException e) {
            e.printStackTrace();
        }
    }
    public  void closed(Connection con,Statement stmt,ResultSet  rs) {//关闭Connetion，Statement，ResultSet
        closedResultSet (rs);
        closedStatement ( stmt);
        closedConnection(con);
    }
    public void closed(Connection con,Statement stmt) {//关闭Connection，Statement
        closedStatement ( stmt);
        closedConnection(con);
    }    
}