代碼：package com.jdbc;import java.sql.Connection;import java.sql.DriverManager;import java.sql.ResultSet;import java.sql.Statement;public class Jdbc { ?private static final String URL ="jdbc:mysql://127.0.0.1:3306/lee"; ?private static final String USER="root"; ?private static final String PASSWORD ="123"; ? ? public static void main (String[ ] ?args) throws Exception ? ?{ ? ? ?? ? ? ? //1.加載驅動程序 Class.forName("com.mysql.jdbc.Driver"); //2.獲得數據庫的連接 Connection conn = DriverManager.getConnection(URL, USER, PASSWORD); //3.通過數據庫的連接操作數據庫，實現增刪改查； Statement stat = conn.createStatement(); ResultSet rs = stat.executeQuery("select ?user_name,age ?from immoc_goddess"); while (rs.next()) { System.out.println(rs.getString("user_name")+","+rs.getString("age")); } ? ? }}下面是異常；異常：Exception in thread "main" java.lang.ClassNotFoundException: com.mysql.jdbc.Driver at java.net.URLClassLoader$1.run(URLClassLoader.java:200) at java.security.AccessController.doPrivileged(Native Method) at java.net.URLClassLoader.findClass(URLClassLoader.java:188) at java.lang.ClassLoader.loadClass(ClassLoader.java:307) at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:301) at java.lang.ClassLoader.loadClass(ClassLoader.java:252) at java.lang.ClassLoader.loadClassInternal(ClassLoader.java:320) at java.lang.Class.forName0(Native Method) at java.lang.Class.forName(Class.java:169) at com.jdbc.Jdbc.main(Jdbc.java:17)