com.mchange.v2.resourcepool.CannotAcquireResourceException

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