org.hibernate.exception.GenericJDBCException: Cannot open connection

看马士兵老师hibernate的视频，用的马老师源码，但运行出错

hibernate.cfg.xml配置文件正确为前提
重新写了个项目
重新编译所有的类
运行成功


<?xml version='1.0' encoding='utf-8'?>
<!DOCTYPE hibernate-configuration PUBLIC
        "-//Hibernate/Hibernate Configuration DTD 3.0//EN"
        "http://hibernate.sourceforge.net/hibernate-configuration-3.0.dtd">

<hibernate-configuration>

    <session-factory>

        <!-- Database connection settings -->
        <property name="connection.driver_class">com.mysql.jdbc.Driver</property>
        <property name="connection.url">jdbc:mysql://localhost:3306/hibernate</property>
        <property name="connection.username">root</property>
        <property name="connection.password">love</property>

        <!-- JDBC connection pool (use the built-in) -->
        <!--<property name="connection.pool_size">1</property>-->

        <!-- SQL dialect -->
        <property name="dialect">org.hibernate.dialect.MySQLDialect</property>

        <!-- Enable Hibernate's automatic session context management -->
        <property name="current_session_context_class">thread</property>

        <!-- Disable the second-level cache  -->
        <property name="cache.provider_class">org.hibernate.cache.NoCacheProvider</property>

        <!-- Echo all executed SQL to stdout -->
        <property name="show_sql">true</property>

        <!-- Drop and re-create the database schema on startup -->
        <!--<property name="hbm2ddl.auto">update</property>-->

        <mapping resource="com/bjsxt/hibernate/Student.hbm.xml"/>
<mapping class="com.bjsxt.hibernate.Teacher"/>
    </session-factory>

</hibernate-configuration>