服务器：阿里云 系统：CentOS 8.1 数据库：MySQL5.7

用localhost和IP都不行，本地连接数据库正常。

com.mysql.jdbc.exceptions.jdbc4.CommunicationsException: Communications link failure

The last packet successfully received from the server was 1 milliseconds ago.  The last packet sent successfully to the server was 1 milliseconds ago.

 at sun.reflect.GeneratedConstructorAccessor125.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:404)

 at com.mysql.jdbc.SQLError.createCommunicationsException(SQLError.java:988)

 at com.mysql.jdbc.ExportControlled.transformSocketToSSLSocket(ExportControlled.java:164)

 at com.mysql.jdbc.MysqlIO.negotiateSSLConnection(MysqlIO.java:4894)

 at com.mysql.jdbc.MysqlIO.proceedHandshakeWithPluggableAuthentication(MysqlIO.java:1661)

 at com.mysql.jdbc.MysqlIO.doHandshake(MysqlIO.java:1228)

 at com.mysql.jdbc.ConnectionImpl.coreConnect(ConnectionImpl.java:2253)

 at com.mysql.jdbc.ConnectionImpl.connectOneTryOnly(ConnectionImpl.java:2284)

 at com.mysql.jdbc.ConnectionImpl.createNewIO(ConnectionImpl.java:2083)

 at com.mysql.jdbc.ConnectionImpl.

 at com.mysql.jdbc.JDBC4Connection.

 at sun.reflect.GeneratedConstructorAccessor121.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:404)

 at com.mysql.jdbc.ConnectionImpl.getInstance(ConnectionImpl.java:410)

 at com.mysql.jdbc.NonRegisteringDriver.connect(NonRegisteringDriver.java:328)

 at com.fr.third.alibaba.druid.pool.DruidAbstractDataSource.createPhysicalConnection(DruidAbstractDataSource.java:1461)

 at com.fr.third.alibaba.druid.pool.DruidAbstractDataSource.createPhysicalConnection(DruidAbstractDataSource.java:1525)

 at com.fr.third.alibaba.druid.pool.DruidDataSource$CreateConnectionThread.run(DruidDataSource.java:2153)

Caused by: javax.net.ssl.SSLException: Received fatal alert: protocol_version

 at sun.security.ssl.Alerts.getSSLException(Alerts.java:208)

 at sun.security.ssl.Alerts.getSSLException(Alerts.java:154)

 at sun.security.ssl.SSLSocketImpl.recvAlert(SSLSocketImpl.java:2023)

 at sun.security.ssl.SSLSocketImpl.readRecord(SSLSocketImpl.java:1125)

 at sun.security.ssl.SSLSocketImpl.performInitialHandshake(SSLSocketImpl.java:1375)

 at sun.security.ssl.SSLSocketImpl.startHandshake(SSLSocketImpl.java:1403)

 at sun.security.ssl.SSLSocketImpl.startHandshake(SSLSocketImpl.java:1387)

 at com.mysql.jdbc.ExportControlled.transformSocketToSSLSocket(ExportControlled.java:149)

 ... 17 more