问一下 PersistenceException怎么解决

这是我的xml文件

<?xml version="1.0" encoding="UTF-8" standalone="no"?>

<!--

       Copyright 2009-2016 the original author or authors.

       Licensed under the Apache License, Version 2.0 (the "License");

       you may not use this file except in compliance with the License.

       You may obtain a copy of the License at

          http://www.apache.org/licenses/LICENSE-2.0

       Unless required by applicable law or agreed to in writing, software

       distributed under the License is distributed on an "AS IS" BASIS,

       WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.

       See the License for the specific language governing permissions and

       limitations under the License.

-->

<!DOCTYPE configuration

    PUBLIC "-//mybatis.org//DTD Config 3.0//EN"

    "http://mybatis.org/dtd/mybatis-3-config.dtd">

<configuration>

<!--

  <settings>

    <setting name="useGeneratedKeys" value="false"/>

    <setting name="useColumnLabel" value="true"/>

  </settings>

  <typeAliases>

    <typeAlias alias="UserAlias" type="org.apache.ibatis.submitted.complex_property.User"/>

  </typeAliases>-->

  <environments default="development">

    <environment id="development">

      <transactionManager type="JDBC">

        <property name="" value=""/>

      </transactionManager>

      <dataSource type="UNPOOLED">

        <property name="driver" value="com.mysql.jdbc.Driver"/>

        <property name="url" value="jdbc:mysql://127.0.0.1:3306/micro_message?serverTimezone=UTC "/>

        <property name="username" value="root"/>

        <property name="password" value="500730"/>

      </dataSource>

    </environment>

  </environments>

<!--

  <mappers>

    <mapper resource="MicroMessage/src/sqlxml/Message.xml"/>

  </mappers>

  -->

</configuration>