java连接mysql错误及解决方案整合

怼烎@ 2022-04-24 11:00 412阅读 0赞

### 1.java.sql.SQLException: Unknown system variable 'query\_cache\_size' ###

mysql-connecter-java的版本过低

**解决方案**

修改mysql依赖的版本

<dependency>
        <groupId>mysql</groupId>
        <artifactId>mysql-connector-java</artifactId>
        <version>8.0.12</version>
    </dependency>

### 2.The server time zone value 'ÖÐ¹ú±ê×¼Ê±¼ä' is unrecognized or represents more than one time zone.... ###

时区错误

**解决方案**

set global time_zone='+8:00';

### 3.The name of the class that implements java.sql.Driver in MySQL Connector/J has changed from com.mysql.jdbc.Driver to com.mysql.cj.jdbc.Driver. The old class name has been deprecated. ###

### 或者 ###

### Could not create connection to database server ###

mysql驱动需要更新，下面语句

改为

mysql依赖语句也要更改

<dependency>
        <groupId>mysql</groupId>
        <artifactId>mysql-connector-java</artifactId>
        <version>8.0.12</version>
    </dependency>

### 4.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. ###

解决方案

修改数据库连接语句connectionURL