缘起

昨晚导入一个ssm框架的项目，访问请求的时候总跟我提无法创建数据库连接的问题，这台新电脑刚刚装系统不久，赶了个新潮，装了个mysql8

坑

错误信息

Type Exception Report

Message Request processing failed; nested exception is org.springframework.transaction.CannotCreateTransactionException: Could not open JDBC Connection for transaction; nested exception is java.sql.SQLNonTransientConnectionException: Could not create connection to database server. Attempted reconnect 3 times. Giving up.

Description The server encountered an unexpected condition that prevented it from fulfilling the request.

Exception
org.springframework.web.util.NestedServletException: Request processing failed; nested exception is org.springframework.transaction.CannotCreateTransactionException: Could not open JDBC Connection for transaction; nested exception is java.sql.SQLNonTransientConnectionException: Could not create connection to database server. Attempted reconnect 3 times. Giving up.
    org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:981)
    org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:860)
    javax.servlet.http.HttpServlet.service(HttpServlet.java:635)
    org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:845)
    javax.servlet.http.HttpServlet.service(HttpServlet.java:742)
    org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
    org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:121)
    org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)
.......

问题定位

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那就是连不上数据库咯
网上找了好多解决方案，不怎么奏效
后来终于知道是MySQL8的一些特性的问题
首先更改下面这玩意

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

再去更改连接驱动器的版本

        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <version>8.0.11</version>
            <scope>runtime</scope>
        </dependency>

改动连接url的配置为

useSSL=false

再跑！

image.png

回去看问题，划拉划拉到最后发现了bug

image.png

serverTimezone=UTC

再跑

image.png

果然，成功运行
附上完整的源配置

    <!-- 配置数据源 -->
    <bean id="dataSource"
          class="org.springframework.jdbc.datasource.DriverManagerDataSource">
        <property name="driverClassName" value="com.mysql.cj.jdbc.Driver"/>
        <property name="url"
                  value="jdbc:mysql://localhost:3306/gitchat_ssm_demo_db?useUnicode=true&amp;characterEncoding=utf8&amp;autoReconnect=true&amp;useSSL=false&amp;serverTimezone=UTC"/>
        <!-- 改为你的地址即可 -->
        <property name="username" value="root"/>
        <property name="password" value="admin"/>
    </bean>

另外就是在pom里面改动数据库驱动的版本，这个上面有

image.png