前言

数据库版本和URL安全（useSSL）的问题:

报错信息

Thu Apr 20 10:23:05 CST 2023 WARN: Establishing SSL connection without server's identity verification is not recommended. According to MySQL 5.5.45+, 5.6.26+ and 5.7.6+ requirements SSL connection must be established by default if explicit option isn't set. For compliance with existing applications not using SSL the verifyServerCertificate property is set to 'false'. You need either to explicitly disable SSL by setting useSSL=false, or set useSSL=true and provide truststore for server certificate verification.
[ERROR] 2023-04-20 10:23:05 com.alibaba.druid.pool.DruidDataSource$CreateConnectionThread.run(DruidDataSource.java:1651)create connection error
  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.GeneratedConstructorAccessor36.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:425)
	at com.mysql.jdbc.SQLError.createCommunicationsException(SQLError.java:989)
	at com.mysql.jdbc.ExportControlled.transformSocketToSSLSocket(ExportControlled.java:164)
	at com.mysql.jdbc.MysqlIO.negotiateSSLConnection(MysqlIO.java:4898)
	at com.mysql.jdbc.MysqlIO.proceedHandshakeWithPluggableAuthentication(MysqlIO.java:1659)
	at com.mysql.jdbc.MysqlIO.doHandshake(MysqlIO.java:1226)
	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.<init>(ConnectionImpl.java:806)
	at com.mysql.jdbc.JDBC4Connection.<init>(JDBC4Connection.java:47)
	at sun.reflect.GeneratedConstructorAccessor30.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:425)
	at com.mysql.jdbc.ConnectionImpl.getInstance(ConnectionImpl.java:410)
	at com.mysql.jdbc.NonRegisteringDriver.connect(NonRegisteringDriver.java:328)
	at com.alibaba.druid.pool.DruidAbstractDataSource.createPhysicalConnection(DruidAbstractDataSource.java:1358)
	at com.alibaba.druid.pool.DruidAbstractDataSource.createPhysicalConnection(DruidAbstractDataSource.java:1414)
	at com.alibaba.druid.pool.DruidDataSource$CreateConnectionThread.run(DruidDataSource.java:1649)
Caused by: javax.net.ssl.SSLHandshakeException: No appropriate protocol (protocol is disabled or cipher suites are inappropriate)
	at sun.security.ssl.HandshakeContext.<init>(HandshakeContext.java:171)
	at sun.security.ssl.ClientHandshakeContext.<init>(ClientHandshakeContext.java:103)
	at sun.security.ssl.TransportContext.kickstart(TransportContext.java:220)
	at sun.security.ssl.SSLSocketImpl.startHandshake(SSLSocketImpl.java:433)
	at com.mysql.jdbc.ExportControlled.transformSocketToSSLSocket(ExportControlled.java:149)
	... 17 more

报错原因

MySQL在高版本需要指明是否进行SSL连接。

查看mysql版本

解决办法

如上图，小编数据库版本为“5.7.29”，在数据库连接URL中添加“useSSL”配置（5.7版本以下有无都可以）；

jdbc:mysql://localhost:3306/zaxkdb?useSSL=false&useUnicode=true&characterEncoding=utf8