启动springboot项目报错org.springframework.jdbc.CannotGetJdbcConnectionException

将springboot项目打包部署到centos7服务器上后，使用java -jar运行报错 org.springframework.jdbc.CannotGetJdbcConnectionException，详细日志如下：

15:23:38.684 [Druid-ConnectionPool-Create-1419064126] ERROR c.a.d.p.DruidDataSource - [run,2787] - create connection SQLException, url: jdbc:mysql://172.161.261.7:3306/xxxx?useUnicode=true&characterEncoding=utf8&zeroDateTimeBehavior=convertToNull&useSSL=true&serverTimezone=GMT%2B8, errorCode 1130, state HY000
Cause: org.springframework.jdbc.CannotGetJdbcConnectionException: Failed to obtain JDBC Connection; nested exception is java.sql.SQLException: null,  message from server: "Host '172.161.261.9' is not allowed to connect to this MySQL server"
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:511)
	at org.springframework.beans.factory.support.AbstractBeanFactory.lambda$doGetBean$0(AbstractBeanFactory.java:324)
	at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:234)
	at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:322)
	at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:207)
	at org.springframework.context.support.PostProcessorRegistrationDelegate.registerBeanPostProcessors(PostProcessorRegistrationDelegate.java:241)
	at org.springframework.context.support.AbstractApplicationContext.registerBeanPostProcessors(AbstractApplicationContext.java:723)
	at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:536)
	at org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.refresh(ServletWebServerApplicationContext.java:141)
	at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:747)
	at org.springframework.boot.SpringApplication.refreshContext(SpringApplication.java:405)
	at org.springframework.boot.SpringApplication.run(SpringApplication.java:315)
	at org.springframework.boot.SpringApplication.run(SpringApplication.java:1226)
	at org.springframework.boot.SpringApplication.run(SpringApplication.java:1215)
	at com.ruoyi.RuoYiApplication.main(RuoYiApplication.java:18)
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
	at java.lang.reflect.Method.invoke(Method.java:498)
	at org.springframework.boot.loader.MainMethodRunner.run(MainMethodRunner.java:48)
	at org.springframework.boot.loader.Launcher.launch(Launcher.java:87)
	at org.springframework.boot.loader.Launcher.launch(Launcher.java:50)
	at org.springframework.boot.loader.JarLauncher.main(JarLauncher.java:51)

原因是mysql只允许localhost或者127.0.0.1登录，只需要把mysql设置为允许外网访问即可，host改为%（或者按需配置为你需要的IP）。

进入mysql，然后查询所有的用户

mysql> use mysql
Reading table information for completion of table and column names
You can turn off this feature to get a quicker startup with -A

Database changed
mysql> select host, user from user;
+-----------+---------------+
| host      | user          |
+-----------+---------------+
| localhost | mysql.session |
| localhost | mysql.sys     |
| localhost | root          |
+-----------+---------------+
3 rows in set (0.00 sec)

然后修改root用户

mysql> update user set host = '%' where user ='root';
Query OK, 1 row affected (0.00 sec)
Rows matched: 1  Changed: 1  Warnings: 0

mysql> flush privileges;
Query OK, 0 rows affected (0.00 sec)

修改后不要忘记执行 flush privileges刷新一下。

在启动项目就好了。