异常：找不到文件/无法解析

如果报错

(nested exception is java.io.FileNotFoundException: class path resource [xx.properties] cannot be opened because it does not exist)

或者

Could not resolve placeholder 'spring.datasource.url' in value "${spring.datasource.url}"

而且你确定resources下正确放置了文件夹，且resources文件夹已经设置为了resources folder，比如这样：

那么你可能需要rebuild project。