SpringBoot启动报错：HikariPool-1 – Exception during pool initialization.

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SpringBoot启动时报错如下：

INFO 15528 --- [       main] com.zaxxer.hikari.HikariDataSource       : HikariPool-1 - Starting...
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 15528 --- [       main] com.zaxxer.hikari.pool.HikariPool        : HikariPool-1 - Exception during pool initialization.

java.sql.SQLException: Access denied for user 'root'@'localhost' (using password: NO)
    at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:965) ~[mysql-connector-java-5.1.46.jar:5.1.46]
    at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:3976) ~[mysql-connector-java-5.1.46.jar:5.1.46]
    at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:3912) ~[mysql-connector-java-5.1.46.jar:5.1.46]
    at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:871) ~[mysql-connector-java-5.1.46.jar:5.1.46]
 at com.mysql.jdbc.MysqlIO.proceedHandshakeWithPluggableAuthentication(MysqlIO.java:1714) ~[mysql-connector-java-5.1.46.jar:5.1.46]
    at com.mysql.jdbc.MysqlIO.doHandshake(MysqlIO.java:1224) ~[mysql-connector-java-5.1.46.jar:5.1.46]

     问题：在Mysql5.5以上的版本中，创建连接时会警告：

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.

翻译：不建议在没有服务器身份验证的情况下建立SSL连接。根据MySQL 5.5.45+、5.6.26+和5.76+的要求，如果不设置显式选项，则必须在默认情况下建立SSL连接。为了遵守不使用SSL的现有应用程序，verifyserver证书属性被设置为“false”。您需要通过设置useSSL=false来显式禁用SSL，或者设置useSSL=true，并为服务器证书验证提供信任存储。

PS：这警告实际上不止出现在启动项目时，在启动MySql服务时，日志中就会给出警告，告知不建议使用没有带服务器身份验证的SSL连接。

报错截图：

  解决：

解决办法在警告中已经说明：

1.在数据库连接的url中添加useSSL=false;

2.url中添加useSSL=true，并且提供服务器的验证证书。

例如：  jdbc:mysql://127.0.0.1:3306/dbname?useSSL=false