Spring起動アプリケーションを起動してJDBC接続を行うと、コンソール上で次の警告メッセージが表示されます。

Fri Feb 10 18:43:02 SGT 2017 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.
//... repeat over and over

接続プロパティは次のとおりです。

application.properties

#mysql datasource
spring.datasource.url=jdbc:mysql://localhost/mkyong
spring.datasource.username=root
spring.datasource.password=password
spring.datasource.driver-class-name=com.mysql.jdbc.Driver


P.S MySQL 5.7.17

でテスト済み

解決策

これを修正するには、MySQL接続文字列の最後に `useSSL = false`を追加します:

application.properties

#mysql datasource
spring.datasource.url=jdbc:mysql://localhost/mkyong?useSSL=false
spring.datasource.username=root
spring.datasource.password=password
spring.datasource.driver-class-name=com.mysql.jdbc.Driver