mysql数据库链接失败

问题遇到的现象和发生背景

org.mybatis.spring.MyBatisSystemException: nested exception is org.apache.ibatis.exceptions.PersistenceException: 
### Error querying database.  Cause: org.springframework.jdbc.CannotGetJdbcConnectionException: Failed to obtain JDBC Connection; nested exception is java.sql.SQLException: An attempt by a client to checkout a Connection has timed out.
### The error may exist in com/dao/StudentMapper.xml
### The error may involve com.dao.StudentMapper.queryAllStudent
### The error occurred while executing a query
### Cause: org.springframework.jdbc.CannotGetJdbcConnectionException: Failed to obtain JDBC Connection; nested exception is java.sql.SQLException: An attempt by a client to checkout a Connection has timed out.

问题相关代码，请勿粘贴截图

URL

dbc.url=jdbc:mysql://localhost:8080/ssmbuild?serverTimezone"+"=UTC&characterEncoding=utf-8&useSSL=false

c3p0

<!-- c3p0连接池的私有属性 -->
        <property name="maxPoolSize" value="30"/>
        <property name="minPoolSize" value="10"/>
        <!-- 关闭连接后不自动commit -->
        <property name="autoCommitOnClose" value="false"/>
        <!-- 获取连接超时时间 -->
        <property name="checkoutTimeout" value="10000"/>
        <!-- 当获取连接失败重试次数 -->
        <property name="acquireRetryAttempts" value="2"/>
    </bean>

运行结果及报错内容

我的解答思路和尝试过的方法

我想要达到的结果

mysql端口是3306，你先把端口改了再试试看。

mysql数据库3306
Oracle的另查
数据库连接没写账户名密码，你的问题发生在查询的时候，而查询失败的原因就是数据库没连接上，检查数据库连接可解决问题