java.lang.NullPointerException - com.mysql.jdbc.ConnectionImpl.getServerCharset

Spring Framework에서 JDBC로 mysql에 접근했는데 다음과 같은 오류가 발생합니다.

HTTP Status 500 – Internal Server Error
Type Exception Report

Message Request processing failed; nested exception is org.mybatis.spring.MyBatisSystemException: nested exception is org.apache.ibatis.exceptions.PersistenceException:

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.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 org.apache.commons.dbcp.SQLNestedException: Cannot create PoolableConnectionFactory (Could not create connection to database server.)
### The error may exist in org/example/repository/UserMapper.java (best guess)
### The error may involve org.example.repository.UserMapper.selectAll
### The error occurred while executing a query
### Cause: org.springframework.jdbc.CannotGetJdbcConnectionException: Failed to obtain JDBC Connection; nested exception is org.apache.commons.dbcp.SQLNestedException: Cannot create PoolableConnectionFactory (Could not create connection to database server.)
...[생략]...
    org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
Root Cause

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 org.apache.commons.dbcp.SQLNestedException: Cannot create PoolableConnectionFactory (Could not create connection to database server.)
### The error may exist in org/example/repository/UserMapper.java (best guess)
### The error may involve org.example.repository.UserMapper.selectAll
### The error occurred while executing a query
### Cause: org.springframework.jdbc.CannotGetJdbcConnectionException: Failed to obtain JDBC Connection; nested exception is org.apache.commons.dbcp.SQLNestedException: Cannot create PoolableConnectionFactory (Could not create connection to database server.)
    org.mybatis.spring.MyBatisExceptionTranslator.translateExceptionIfPossible(MyBatisExceptionTranslator.java:75)
...[생략]...
    org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
Root Cause

org.apache.ibatis.exceptions.PersistenceException: 
### Error querying database.  Cause: org.springframework.jdbc.CannotGetJdbcConnectionException: Failed to obtain JDBC Connection; nested exception is org.apache.commons.dbcp.SQLNestedException: Cannot create PoolableConnectionFactory (Could not create connection to database server.)
### The error may exist in org/example/repository/UserMapper.java (best guess)
### The error may involve org.example.repository.UserMapper.selectAll
### The error occurred while executing a query
### Cause: org.springframework.jdbc.CannotGetJdbcConnectionException: Failed to obtain JDBC Connection; nested exception is org.apache.commons.dbcp.SQLNestedException: Cannot create PoolableConnectionFactory (Could not create connection to database server.)
    org.apache.ibatis.exceptions.ExceptionFactory.wrapException(ExceptionFactory.java:26)
...[생략]...
    org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
Root Cause

org.springframework.jdbc.CannotGetJdbcConnectionException: Failed to obtain JDBC Connection; nested exception is org.apache.commons.dbcp.SQLNestedException: Cannot create PoolableConnectionFactory (Could not create connection to database server.)
    org.springframework.jdbc.datasource.DataSourceUtils.getConnection(DataSourceUtils.java:82)
...[생략]...
    org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
Root Cause

org.apache.commons.dbcp.SQLNestedException: Cannot create PoolableConnectionFactory (Could not create connection to database server.)
    org.apache.commons.dbcp.BasicDataSource.createPoolableConnectionFactory(BasicDataSource.java:1549)
...[생략]...
    org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
Root Cause

com.mysql.jdbc.exceptions.jdbc4.MySQLNonTransientConnectionException: Could not create connection to database server.
    java.base/jdk.internal.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
...[생략]...
    org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
Root Cause

java.lang.NullPointerException
    com.mysql.jdbc.ConnectionImpl.getServerCharset(ConnectionImpl.java:2983)
...[생략]...
    org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
Note The full stack trace of the root cause is available in the server logs.

// pom.xml

        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <version>8.0.26</version>
        </dependency>

// applicationContext.xml

    <bean id="dataSource" class="org.springframework.jdbc.datasource.DriverManagerDataSource">
        <property name="driverClassName" value="com.mysql.jdbc.Driver" />
        <property name="url" value="jdbc:mysql://localhost:3306/test?serverTimezone=Asia/Seoul&amp;useSSL=false" />
        <property name="username" value="..." />
        <property name="password" value="..." />
    </bean>

Java에서 MySQL 사용
; https://www.sysnet.pe.kr/2/0/1127

mysql-connector-java 6.xx대로 변경시 주의 사항
; https://effectivesquid.tistory.com/entry/mysqlconnectorjava-6xx%EB%8C%80%EB%A1%9C-%EB%B3%80%EA%B2%BD%EC%8B%9C-%EC%A3%BC%EC%9D%98-%EC%82%AC%ED%95%AD

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