Spring bean中数据库连接报错：java.sql.SQLException: Connections could not be acquired from the underlying dat_springmvc sqlserver connections could not be acqui

利用c3p0数据库连接池配置Spring bean数据源时报错：java.sql.SQLException: Connections could not be acquired from the underlying database! c3p0数据库连接池报错：Caused by: com.mchange.v2.resourcepool.CannotAcquireResourceException: A ResourcePool could not acquire a resource from its primary factory or source.

原因：mysql版本8.0以上，使用jdbc连接时url需加上时区等信息，驱动driverClass需改成com.mysql.cj.jdbc.Driver

解决方法：

1）maven中配置高版本mysql-connector-java和c3p0包：

    <dependency>
        <groupId>mysql</groupId>
        <artifactId>mysql-connector-java</artifactId>
        <version>8.0.11</version>
    </dependency>
    <dependency>
        <groupId>com.mchange</groupId>
        <artifactId>c3p0</artifactId>
        <version>0.9.5.2</version>
    </dependency>
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2.1）由于bean中&字符的限制，在resources中添加配置文件c3p0.properties配置url

url=jdbc:mysql://localhost:3306/eesy?useUnicode=true&characterEncoding=utf-8&useSSL=false&serverTimezone=GMT
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2.1.1）bean中引用外部配置文件c3p0.properties

<!--配置数据源-->
    <context:property-placeholder location="classpath:c3p0.properties"/>
    <bean id="dateSource" class="com.mchange.v2.c3p0.ComboPooledDataSource">
        <!--连接数据库的必备信息-->
        <property name="driverClass" value="com.mysql.cj.jdbc.Driver"></property>
<!--        <property name="jdbcUrl" value="jdbc:mysql://localhost:3306/eesy"></property>-->
        <property name="jdbcUrl" value="${url}"></property>
        <property name="user" value="root"></property>
        <property name="password" value="123456"></property>
    </bean>
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2.2.1）或者在xml使用&代替&