Exception in thread "main" java.sql.SQLException: Connections could not be acquired from the underlying database!
<pre name="code" class="html">Caused by: com.mchange.v2.resourcepool.CannotAcquireResourceException: A ResourcePool could not acquire a resource from its primary factory or source.
这是链接不到数据库，原因多种，我遇到一种，就是我的数据库没有设置密码，而我设置了密码去使用
user=root password=123 driverclass=com.mysql.jdbc.Driver jdbcurl=jdbc:mysql://localhost:3306/hibernate
后来改成无密码，则对上了
user=root password= driverclass=com.mysql.jdbc.Driver jdbcurl=jdbc:mysql://localhost:3306/hibernate