The spark program remotely connects to the mysql database and reports an error

Exception in thread "main" java.sql.SQLException: null,  message from server: "Host '192.168.1.121' is not allowed to connect to this MySQL server"

Reason for error: mysql server does not allow remote connection

After searching for information, the solution is as follows:

Log in to the mysql database:

mysql -uroot -p

carried out

use mysql；

show tables；

View: select host from user;

修改：update user set host = '%' where user = 'root';

Then restart the mysql service and resubmit the spark program to successfully write the data to mysql