今天新搭建了一个springboot+gradle框架，然而，刚搭建好运行的时候，就报了一个错误：
Error starting ApplicationContext. To display the conditions report re-run your application with ‘debug’ enabled.
2018-11-19 13:59:44.020 ERROR 1256 — [ main] o.s.b.d.LoggingFailureAnalysisReporter :

APPLICATION FAILED TO START

Description:
Failed to configure a DataSource: ‘url’ attribute is not specified and no embedded datasource could be configured.
Reason: Failed to determine a suitable driver class
Action:
Consider the following:
If you want an embedded database (H2, HSQL or Derby), please put it on the classpath.
If you have database settings to be loaded from a particular profile you may need to activate it (no profiles are currently active).

    问过度娘娘后，才知道，需要在启动类的@EnableAutoConfiguration或@SpringBootApplication中添加exclude= {DataSourceAutoConfiguration.class}，排除此类的autoconfig。启动以后就可以正常运行。
这是因为添加了数据库组件，所以autoconfig会去读取数据源配置，而我新建的项目还没有配置数据源，所以会导致异常出现。
    照着改过之后，再次运行，就可以了，亲测。。。