The SpringBoot program connects to the Ali server mysql and appears Access denied for user'root'@'own computer's public network ip' (using password: YES)

1, caused by the incident

• I am using Ali server, and MySQL is installed in it. When connecting with SpringBoot, the error shown in the title appears. Access denied for user'root'@'own computer's public network ip' (using password: YES)

2. The first idea

• The remote authority of the database is not open, so modify it
• Enter MySQL

 mysql -u root -p

• Login after entering the password

GRANT ALL PRIVILEGES ON *.* TO 'root'@'%' IDENTIFIED BY '你的数据库密码'  

• Refresh permissions

flush privileges; 

• After this was done, it was unsuccessful and still not resolved, so the problem does not appear here.

3. View the configuration file

• Found low-level errors here

spring:
  main:
    allow-bean-definition-overriding: true
  datasource:
    url: jdbc:mysql://ip:3306/database
    driver-class-name: com.mysql.jdbc.Driver
    name: root
    password: 123456

• In the above configuration file, the name attribute is wrong, and name is the name of the datasource. Since it was not found before, we have been investigating it.
• Modify, change to username, username is the attribute of logging in to the database

spring:
  main:
    allow-bean-definition-overriding: true
  datasource:
    url: jdbc:mysql://ip:3306/database
    driver-class-name: com.mysql.jdbc.Driver
    password: 123456
    username: root

• Before this, I also modified DNS and so on, but all failed, so next time I make this mistake, I still have to start with the configuration file.