java.sql.SQLException: url not set

首先检查@ConfigurationProperties(prefix = "spring.datasource.druid")配置的prefix和.yml（.properties）中的是否一致

其次检查数据库连接中是否有&serverTimezone=UTC

最后检查yml配置文件是否成功加载，如果未加载，在pom.xml文件的在元素添加如下配置

        <resources>
            <resource>
                <directory>src/main/java</directory>
                <includes>
                    <include>**/*.yml</include>
                    <include>**/*.properties</include>
                    <include>**/*.xml</include>
                </includes>
                <filtering>false</filtering>
            </resource>
            <resource>
                <directory>src/main/resources</directory>
                <includes>
                    <include>**/*.yml</include>
                    <include>**/*.properties</include>
                    <include>**/*.xml</include>
                </includes>
                <filtering>false</filtering>
            </resource>
        </resources>