Springboot 模块化 url 报错 The url cannot be null

springboot 多模块报如下错误，原因是我的service模块里还有一个 application.properties,删了就好了。

console 错误：

2018-08-08 17:15:55.833 ERROR 8084 --- [nio-8080-exec-1] o.a.c.c.C.[.[.[/].[dispatcherServlet]    : Servlet.service() for servlet [dispatcherServlet] in context with path [] threw exception [Request processing failed; nested exception is org.mybatis.spring.MyBatisSystemException: nested exception is org.apache.ibatis.exceptions.PersistenceException: 
### Error querying database.  Cause: org.springframework.jdbc.CannotGetJdbcConnectionException: Could not get JDBC Connection; nested exception is java.sql.SQLException: The url cannot be null
### The error may exist in file [E:\webapp2\muitymodel\mm-dao\target\classes\mybatis\StudentMapper.xml]
### The error may involve com.example.mapper.StudentMapper.selectByExample
### The error occurred while executing a query
### Cause: org.springframework.jdbc.CannotGetJdbcConnectionException: Could not get JDBC Connection; nested exception is java.sql.SQLException: The url cannot be null] with root cause

java.sql.SQLException: The url cannot be null

分析 ：确实是jdbc的问题但是就是没找到

配置没问题
spring.datasource.url=jdbc:mysql://127.0.0.1:3306/mydata-test
spring.datasource.username=root
spring.datasource.password=root
spring.datasource.driver-class-name=com.mysql.jdbc.Driver

解决方案：百度发现https://stackoverflow.com/questions/41960563/java-sql-sqlexception-the-url-cannot-be-null-multi-modules-app 里面的一句话 

大体意思是：这哥们俩在评论里聊的内容说，你项目里还有其他配置文件吗？

他说我不确定。然后我去看了一下，我的service模块里还有一个 application.properties 哈哈

删了就好了。

附带 完美教程我参考的别人的  

https://www.jb51.net/article/123051.htm

springboot 模块化 构建 我成功了！