問題：
啓動SpringBoot項目報錯：
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APPLICATION FAILED TO START
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Description:
The bean 'dataSource', defined in BeanDefinition defined in class path resource [org/springframework/boot/autoconfigure/jdbc/DataSourceConfiguration$Hikari.class], could not be registered. A bean with that name has already been defined in class path resource [org/springframework/boot/autoconfigure/jdbc/DataSourceConfiguration$Hikari.class] and overriding is disabled.
Action:
Consider renaming one of the beans or enabling overriding by setting spring.main.allow-bean-definition-overriding=true
Error starting ApplicationContext. To display the conditions report re-run your application with 'debug' enabled.
2019-01-11 10:55:38.248 ERROR 12708 --- [ main] o.s.b.d.LoggingFailureAnalysisReporter :
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APPLICATION FAILED TO START
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Description:
The bean 'dataSource', defined in BeanDefinition defined in class path resource [org/springframework/boot/autoconfigure/jdbc/DataSourceConfiguration$Hikari.class], could not be registered. A bean with that name has already been defined in class path resource [org/springframework/boot/autoconfigure/jdbc/DataSourceConfiguration$Hikari.class] and overriding is disabled.
Action:
Consider renaming one of the beans or enabling overriding by setting spring.main.allow-bean-definition-overriding=true
Process finished with exit code 1
原因：
SpringBoot和SpringCloud的版本不兼容造成。
這裏因爲SpringBoot想嚐鮮使用了2.1.1，而SpringCloud仍然用的是Finchley.SR2，而它支持的是2.0.x及以下版本。
對應的版本應該使用Greenwich.M1。
Issues回答：
解決：
降SpringBoot版本或者使用Greenwich.M1。
所以還是建議直接在start.spring.io上構建新項目，或者在idea上構建項目的時候選擇Spring Initializr來避免版本不兼容。
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原文：https://blog.csdn.net/u012211603/article/details/83714285