【求助】jsp页面连接数据库失败 - Java / Java EE

数据库是mysql，TOMCAT的\conf\Catalina\localhost\dd.xml配置如下：
<?xml version="1.0" encoding="GBK"?>
<Context docBase="D:\work\codes\01\aa" debug="0" privileged="true">
  <Resource name="jdbc/dstest" auth="Container" type="javax.sql.DataSource"
  maxActive="5" maxIdle="2" maxWait="10000"
  username="root" password="root"
driverClassName="com.mysql.jdbc.Driver"
  url="jdbc:mysql://localhost:8088/j2ee"/>
</Context>
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JSP页面报错如下：
HTTP Status 500 - 

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type Exception report

message 

description The server encountered an internal error () that prevented it from fulfilling this request.

exception 

org.apache.jasper.JasperException: javax.servlet.ServletException: org.apache.tomcat.dbcp.dbcp.SQLNestedException: Cannot create PoolableConnectionFactory (Communications link failure

Last packet sent to the server was 0 ms ago.)
org.apache.jasper.servlet.JspServletWrapper.handleJspException(JspServletWrapper.java:491)
org.apache