can't connect to myql 8.0.19

[cuihairu]

Issue Description

can't connect to myql 8.0.19

Describe what happened (or what feature you want)

stack:

Caused by: com.mysql.jdbc.exceptions.jdbc4.MySQLNonTransientConnectionException: Could not create connection to database server. Attempted reconnect 3 times. Giving up.
        at sun.reflect.GeneratedConstructorAccessor74.newInstance(Unknown Source)
        at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
        at java.lang.reflect.Constructor.newInstance(Constructor.java:423)
        at com.mysql.jdbc.Util.handleNewInstance(Util.java:377)
        at com.mysql.jdbc.Util.getInstance(Util.java:360)
        at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:956)
        at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:935)
        at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:924)
        at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:870)
        at com.mysql.jdbc.ConnectionImpl.connectWithRetries(ConnectionImpl.java:2144)
        at com.mysql.jdbc.ConnectionImpl.createNewIO(ConnectionImpl.java:2069)
        at com.mysql.jdbc.ConnectionImpl.<init>(ConnectionImpl.java:790)
        at com.mysql.jdbc.JDBC4Connection.<init>(JDBC4Connection.java:44)
        at sun.reflect.GeneratedConstructorAccessor72.newInstance(Unknown Source)
        at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
        at java.lang.reflect.Constructor.newInstance(Constructor.java:423)
        at com.mysql.jdbc.Util.handleNewInstance(Util.java:377)
        at com.mysql.jdbc.ConnectionImpl.getInstance(ConnectionImpl.java:395)
        at com.mysql.jdbc.NonRegisteringDriver.connect(NonRegisteringDriver.java:325)
        at org.apache.commons.dbcp.DriverConnectionFactory.createConnection(DriverConnectionFactory.java:38)
        at org.apache.commons.dbcp.PoolableConnectionFactory.makeObject(PoolableConnectionFactory.java:582)
        at org.apache.commons.dbcp.BasicDataSource.validateConnectionFactory(BasicDataSource.java:1556)
        at org.apache.commons.dbcp.BasicDataSource.createPoolableConnectionFactory(BasicDataSource.java:1545)
        ... 15 more
Caused by: java.lang.NullPointerException
        at com.mysql.jdbc.ConnectionImpl.getServerCharset(ConnectionImpl.java:2983)
        at com.mysql.jdbc.MysqlIO.sendConnectionAttributes(MysqlIO.java:1873)
        at com.mysql.jdbc.MysqlIO.proceedHandshakeWithPluggableAuthentication(MysqlIO.java:1802)
        at com.mysql.jdbc.MysqlIO.doHandshake(MysqlIO.java:1206)
        at com.mysql.jdbc.ConnectionImpl.coreConnect(ConnectionImpl.java:2234)
        at com.mysql.jdbc.ConnectionImpl.connectWithRetries(ConnectionImpl.java:2085)
        ... 28 more

Describe what you expected to happen

connect to mysql 8.19

How to reproduce it (as minimally and precisely as possible)

1. install mysql8.19
2. config nacos use mysql
3. start nacos server

Tell us your environment

1. os: CentOS7

uname -a
# Linux 3.10.0-1062.9.1.el7.x86_64 #1 SMP Fri Dec 6 15:49:49 UTC 2019 x86_64 x86_64 x86_64 GNU/Linux

2. mysql:

mysql> select version();
+-----------+
| version() |
+-----------+
| 8.0.19    |
+-----------+
1 row in set (0.00 sec)

Anything else we need to know?

see also:

1. https://bugs.mysql.com/bug.php?id=86221
2. nacos pom.xml

<!-- JDBC libs -->
<dependency>
    <groupId>mysql</groupId>
    <artifactId>mysql-connector-java</artifactId>
    <version>5.1.34</version>
</dedependency>

[paderlol]

You can find the answer you need in this [https://github.com/alibaba/nacos/issues/2242]( Duplicate of #2242 )