SpringBoot 常见问题记录

问题一

Error starting ApplicationContext. To display the auto-configuration report re-run your application with 'debug' enabled.
2017-11-06 15:52:21.964 ERROR 49864 --- [           main] o.s.b.d.LoggingFailureAnalysisReporter   : 
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APPLICATION FAILED TO START
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Description:

Cannot determine embedded database driver class for database type NONE

Action:

If you want an embedded database please put a supported one on the classpath. If you have database settings to be loaded from a particular profile you may need to active it (no profiles are currently active).

原因：

　　spring boot默认会加载org.springframework.boot.autoconfigure.jdbc.DataSourceAutoConfiguration类，DataSourceAutoConfiguration类使用了@Configuration注解向spring注入了dataSource bean。因为工程中没有关于dataSource相关的配置信息，当spring创建dataSource bean因缺少相关的信息就会报错。

解决方法：

　　在Application类上增加@EnableAutoConfiguration(exclude={DataSourceAutoConfiguration.class})       或者    配置dataSource

问题二

Whitelabel Error Page

This application has no explicit mapping for /error, so you are seeing this as a fallback.

Mon Nov 06 16:40:38 CST 2017
There was an unexpected error (type=Not Found, status=404).
No message available

原因：

　　Application启动类放的位置不对，要将Application放在最外层，也就是要包含所有子包。springboot会自动加载启动类所在包下及其子包下的所有组件。