在Docker容器中将Spring与MySql连接起来

Question

当我按照本教程：https://spring.io/guides/gs/accessing-data-mysql/#initial并启动一些新的docker容器时：

version: '2'

services:
    db:
      image: mysql
      environment:
                - MYSQL_DATABASE=test
                - MYSQL_USER=test
                - MYSQL_PASSWORD=secret
                - MYSQL_ROOT_PASSWORD=root
      volumes:
            - ./db:/var/lib/mysql
      ports:
            - "3306:3306"
    phpmyadmin:
     image: phpmyadmin/phpmyadmin
     environment:
            PMA_ARBITRARY: 1
            MYSQL_USER: test
            MYSQL_PASSWORD: secret
            MYSQL_ROOT_PASSWORD: root
     ports:
            - "80:80"
     links:
            # for mysql container
            - "db:db"
volumes:
    db:
        driver: "local"

我无法连接MySql数据库，当我在Spring中运行示例应用程序时，我收到错误：

Unable to create initial connections of pool.

com.mysql.jdbc.exceptions.jdbc4.CommunicationsException: Communications link failure

The last packet sent successfully to the server was 0 milliseconds ago. The driver has not received any packets from the server.

我的应用程序属性：

spring.jpa.hibernate.ddl-auto=create
spring.datasource.url=jdbc:mysql://db:3306/test
spring.datasource.username=springuser
spring.datasource.password=ThePassword

出了什么问题？我也试过像localhost这样的不同组合。我可以在浏览器中访问phpmyadmin。