数据库启动了也没有设置密码，但是运行一直报错

java.lang.ClassNotFoundException: com.mysql.jdbc.Driver

at java.net.URLClassLoader.findClass(URLClassLoader.java:382)

at java.lang.ClassLoader.loadClass(ClassLoader.java:424)

at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:349)

at java.lang.ClassLoader.loadClass(ClassLoader.java:357)

at java.lang.Class.forName0(Native Method)

at java.lang.Class.forName(Class.java:264)

at util.DBHelper.<clinit>(DBHelper.java:21)

java.sql.SQLException: No suitable driver found for jdbc:mysql://localhost:3306/shopping?useUnicode=true&characterEncoding=UTF-8

at java.sql.DriverManager.getConnection(DriverManager.java:689)

at java.sql.DriverManager.getConnection(DriverManager.java:247)

at util.DBHelper.getConnection(DBHelper.java:34)

at util.DBHelper.main(DBHelper.java:44)