com.alibaba.druid.pool.DruidDataSource : create connection SQLException, url: jdbc:mysql:/解决方法详解

com.mysql.jdbc.exceptions.jdbc4.MySQLNonTransientConnectionException: Could not create connection to database server.
具体错误信息如下：
2021-01-04 20:20:09.071 ERROR 12300 --- [eate-2022120039] com.alibaba.druid.pool.DruidDataSource   : create connection SQLException, url: jdbc:mysql://localhost:3306/blog_system?serverTimezone=UTC&useSSL=false, errorCode 0, state 08001
 
com.mysql.jdbc.exceptions.jdbc4.MySQLNonTransientConnectionException: Could not create connection to database server.
    at jdk.internal.reflect.GeneratedConstructorAccessor51.newInstance(Unknown Source) ~[na:na]
    at java.base/jdk.internal.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45) ~[na:na]
    at java.base/java.lang.reflect.Constructor.newInstanceWithCaller(Constructor.java:500) ~[na:na]
    at java.base/java.lang.reflect.Constructor.newInstance(Constructor.java:481) ~[na:na]
    at com.mysql.jdbc.Util.handleNewInstance(Util.java:404) ~[mysql-connector-java-5.1.37.jar:5.1.37]
    at com.mysql.jdbc.Util.getInstance(Util.java:387) ~[mysql-connector-java-5.1.37.jar:5.1.37]
    at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:919) ~[mysql-connector-java-5.1.37.jar:5.1.37]
    at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:898) ~[mysql-connector-java-5.1.37.jar:5.1.37]
    at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:887) ~[mysql-connector-java-5.1.37.jar:5.1.37]
    at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:862) ~[mysql-connector-java-5.1.37.jar:5.1.37]
    at com.mysql.jdbc.ConnectionImpl.connectOneTryOnly(ConnectionImpl.java:2331) ~[mysql-connector-java-5.1.37.jar:5.1.37]
    at com.mysql.jdbc.ConnectionImpl.createNewIO(ConnectionImpl.java:2084) ~[mysql-connector-java-5.1.37.jar:5.1.37]
    at com.mysql.jdbc.ConnectionImpl.<init>(ConnectionImpl.java:795) ~[mysql-connector-java-5.1.37.jar:5.1.37]
    at com.mysql.jdbc.JDBC4Connection.<init>(JDBC4Connection.java:44) ~[mysql-connector-java-5.1.37.jar:5.1.37]
    at jdk.internal.reflect.GeneratedConstructorAccessor48.newInstance(Unknown Source) ~[na:na]
    at java.base/jdk.internal.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45) ~[na:na]
    at java.base/java.lang.reflect.Constructor.newInstanceWithCaller(Constructor.java:500) ~[na:na]
    at java.base/java.lang.reflect.Constructor.newInstance(Constructor.java:481) ~[na:na]
    at com.mysql.jdbc.Util.handleNewInstance(Util.java:404) ~[mysql-connector-java-5.1.37.jar:5.1.37]
    at com.mysql.jdbc.ConnectionImpl.getInstance(ConnectionImpl.java:400) ~[mysql-connector-java-5.1.37.jar:5.1.37]
    at com.mysql.jdbc.NonRegisteringDriver.connect(NonRegisteringDriver.java:327) ~[mysql-connector-java-5.1.37.jar:5.1.37]
    at com.alibaba.druid.filter.FilterChainImpl.connection_connect(FilterChainImpl.java:156) ~[druid-1.1.10.jar:1.1.10]
    at com.alibaba.druid.filter.stat.StatFilter.connection_connect(StatFilter.java:218) ~[druid-1.1.10.jar:1.1.10]
    at com.alibaba.druid.filter.FilterChainImpl.connection_connect(FilterChainImpl.java:150) ~[druid-1.1.10.jar:1.1.10]
    at com.alibaba.druid.pool.DruidAbstractDataSource.createPhysicalConnection(DruidAbstractDataSource.java:1560) ~[druid-1.1.10.jar:1.1.10]
    at com.alibaba.druid.pool.DruidAbstractDataSource.createPhysicalConnection(DruidAbstractDataSource.java:1623) ~[druid-1.1.10.jar:1.1.10]
    at com.alibaba.druid.pool.DruidDataSource$CreateConnectionThread.run(DruidDataSource.java:2468) ~[druid-1.1.10.jar:1.1.10]
Caused by: java.lang.NullPointerException: null
    at com.mysql.jdbc.ConnectionImpl.getServerCharset(ConnectionImpl.java:3004) ~[mysql-connector-java-5.1.37.jar:5.1.37]
    at com.mysql.jdbc.MysqlIO.sendConnectionAttributes(MysqlIO.java:1908) ~[mysql-connector-java-5.1.37.jar:5.1.37]
    at com.mysql.jdbc.MysqlIO.proceedHandshakeWithPluggableAuthentication(MysqlIO.java:1837) ~[mysql-connector-java-5.1.37.jar:5.1.37]
    at com.mysql.jdbc.MysqlIO.doHandshake(MysqlIO.java:1207) ~[mysql-connector-java-5.1.37.jar:5.1.37]
    at com.mysql.jdbc.ConnectionImpl.coreConnect(ConnectionImpl.java:2254) ~[mysql-connector-java-5.1.37.jar:5.1.37]
    at com.mysql.jdbc.ConnectionImpl.connectOneTryOnly(ConnectionImpl.java:2285) ~[mysql-connector-java-5.1.37.jar:5.1.37]
    ... 16 common frames omitted
解决方法：
这种就是 数据库不兼容，应该是本机的MYSQL版本太高了
 

MySQL数据库比较不好的一点是 8.0以上版本应该是不兼容 5.0版本。所以只能删除了自己本机的MySQL数据库，提前把数据导出SQL文件，下载新的数据库再倒入数据。这里推荐  直接下载 phpstudy pro这个软件，里面自带了MySQL 各个版本的数据库，使用更加方便快捷，切记每次使用时开启数据库。这是我目前使用的：

然后问题就解决了