Docker Compose : SpringBoot application with mysql:8

Question

Below is my docker-compose.yml which composing two docker files :

1. mysql.dockerfile

   FROM mysql:8  
   ADD DockerImages/mysql /docker-entrypoint-initdb.d/
   

2. springapp.dockerfile

   FROM maven:3.5-jdk-8 <br>
   ADD target/users-mysql.jar users-mysql.jar<br>
   ENTRYPOINT ["/usr/bin/java"]<br>
   CMD ["-jar", "users-mysql.jar"]<br>
   VOLUME /var/lib/spring-cloud/config-repo
   

3. docker-compose.yml

   version: '3'

   services:
   
     springapp:
       build: 
         context: . 
         dockerfile: springapp.dockerfile
       expose:
         - "8888"
       ports:
         - 8888:8888
       links:
         - mysqldb:mysqldb
       networks:
         - spring-demo-network
       depends_on:
         - mysqldb      
       environment:
         - DATABASE_HOST=mysqldb
         - DATABASE_USER=gl_user
         - DATABASE_PASSWORD=global@123
         - DATABASE_NAME=test_db
   
     mysqldb:
       build: 
         context: . 
         dockerfile: mysql.dockerfile
       ports:
         - 3306:3306
       container_name : mysql-standalone
       networks:
         - spring-demo-network
       environment:
         MYSQL_DATABASE: test_db
         MYSQL_USER: gl_user
         MYSQL_PASSWORD: global@123
         MYSQL_ROOT_PASSWORD: root
         MYSQL_ROOT_HOST: '%'         
   
   networks:
     spring-demo-network:
       driver: bridge
   

I am unable to connect to the database its throws multiple errors like Error:

• java.sql.SQLException: null, message from server: "Host '172.18.0.3' is not allowed to connect to this MySQL server"
• Caused by: java.net.ConnectException: Connection refused (Connection refused)