問一下 PersistenceException怎么解決
這是我的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>
2020-02-03
public class MessageDao {
?public List<Message> queryMessageList(String command,String description) {
??DBAccess dbAccess = new DBAccess();
??List<Message> messages = new ArrayList<Message>();
??SqlSession sqlSession = null;
??try {
???sqlSession = dbAccess.getSqlSession();
???//通過sqlSession執行SQL語句
???messages = sqlSession.selectList("Message.queryMessageList");
??} catch (IOException e) {
???// TODO Auto-generated catch block
???e.printStackTrace();
??} finally {
???if (sqlSession!=null) {
????sqlSession.close();
???}
??}
??return messages;
?}