我尝试在Docker上使用mysql连接运行Springboot应用程序。没有码头工人，它运作良好。但是，当我尝试在容器上进行部署时，我有com.mysql.cj.exceptions.CJCommunicationsException: Communications link failure。我使用这个docker-compose：
com.mysql.cj.exceptions.CJCommunicationsException: Communications link failure
version: '3' services: nginx: container_name: nginx image: nginx:latest restart: always ports: - 80:80 - 443:443 volumes: - ./nginx/conf.d:/etc/nginx/conf.d depends_on: - spring-boot-app mysql: container_name: mysql image: mysql:latest environment: MYSQL_ROOT_PASSWORD: "rootpass" MYSQL_DATABASE: "db" MYSQL_USER: "user" MYSQL_PASSWORD: "pass" ports: - "1306:3306" volumes: - ./data/:/var/lib/mysql networks: - mysql-db restart: always spring-boot-app: container_name: spring-boot-app image: spring-boot-app build: context: ./spring-boot-app dockerfile: Dockerfile ports: - "8080:8080" depends_on: - mysql networks: - mysql-db restart: always networks: mysql-db: driver: bridge
这是springboot应用程序的Dockerfile：
FROM openjdk:11 COPY target/spring-boot-app.jar /spring-boot-app/spring-boot-app.jar ENTRYPOINT [ "java", "-jar", "-Dspring.profiles.active=prod","/spring-boot-app/spring-boot-app.jar" ]
最后，这是application.properties：
spring.datasource.url = jdbc:mysql://mysql:1306/db spring.datasource.username = user spring.datasource.password = pass # Show or not log for each sql query spring.jpa.show-sql = true # Hibernate ddl auto (create, create-drop, update) spring.jpa.hibernate.ddl-auto = update # Use spring.jpa.properties.* for Hibernate native properties (the prefix is # stripped before adding them to the entity manager) # The SQL dialect makes Hibernate generate better SQL for the chosen database spring.jpa.properties.hibernate.dialect = org.hibernate.dialect.MySQL5Dialect server.port=8080
我不认为这是端口问题，因为我尝试将mysql设置为默认端口（3306），但仍然无法正常工作。
如果可以帮助，这里是docker ps：
docker ps
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES 08ea16361c61 nginx:latest "nginx -g 'daemon of…" 1 second ago Up Less than a second 0.0.0.0:80->80/tcp, 0.0.0.0:443->443/tcp nginx 52ef8d5c2127 spring-boot-app "java -jar -Dspring.…" 3 seconds ago Up 1 second 0.0.0.0:8080->8080/tcp spring-boot-app 7bbcdc1fae3c mysql:latest "docker-entrypoint.s…" 4 seconds ago Up 3 seconds 33060/tcp, 0.0.0.0:1306->3306/tcp mysql
编辑：完整的堆栈跟踪：
ubuntu@ubuntu:~/Documents/SpringBoot$ docker-compose up Creating network "springboot_mysql-db" with driver "bridge" Creating mysql ... done Creating spring-boot-app ... done Attaching to mysql, spring-boot-app mysql | 2019-05-27T21:50:19.645920Z 0 [Warning] [MY-011070] [Server] 'Disabling symbolic links using --skip-symbolic-links (or equivalent) is the default. Consider not using this option as it' is deprecated and will be removed in a future release. mysql | 2019-05-27T21:50:19.645986Z 0 [System] [MY-010116] [Server] /usr/sbin/mysqld (mysqld 8.0.16) starting as process 1 mysql | 2019-05-27T21:50:20.451523Z 0 [System] [MY-010229] [Server] Starting crash recovery... mysql | 2019-05-27T21:50:20.466040Z 0 [System] [MY-010232] [Server] Crash recovery finished. mysql | 2019-05-27T21:50:20.544487Z 0 [Warning] [MY-010068] [Server] CA certificate ca.pem is self signed. mysql | 2019-05-27T21:50:20.551894Z 0 [Warning] [MY-011810] [Server] Insecure configuration for --pid-file: Location '/var/run/mysqld' in the path is accessible to all OS users. Consider choosing a different directory. mysql | 2019-05-27T21:50:20.584210Z 0 [System] [MY-010931] [Server] /usr/sbin/mysqld: ready for connections. Version: '8.0.16' socket: '/var/run/mysqld/mysqld.sock' port: 3306 MySQL Community Server - GPL. mysql | 2019-05-27T21:50:20.682338Z 0 [System] [MY-011323] [Server] X Plugin ready for connections. Socket: '/var/run/mysqld/mysqlx.sock' bind-address: '::' port: 33060 spring-boot-app | spring-boot-app | . ____ _ __ _ _ spring-boot-app | /\\ / ___'_ __ _ _(_)_ __ __ _ \ \ \ \ spring-boot-app | ( ( )\___ | '_ | '_| | '_ \/ _` | \ \ \ \ spring-boot-app | \\/ ___)| |_)| | | | | || (_| | ) ) ) ) spring-boot-app | ' |____| .__|_| |_|_| |_\__, | / / / / spring-boot-app | =========|_|==============|___/=/_/_/_/ spring-boot-app | :: Spring Boot :: (v2.1.5.RELEASE) spring-boot-app | spring-boot-app | 2019-05-27 21:50:22.884 INFO 1 --- [ main] com.jv.demo.DemoApplication : Starting DemoApplication v0.0.1-SNAPSHOT on c69469fd7461 with PID 1 (/spring-boot-app/spring-boot-app.jar started by root in /) spring-boot-app | 2019-05-27 21:50:22.903 INFO 1 --- [ main] com.jv.demo.DemoApplication : The following profiles are active: prod spring-boot-app | 2019-05-27 21:50:25.152 INFO 1 --- [ main] .s.d.r.c.RepositoryConfigurationDelegate : Bootstrapping Spring Data repositories in DEFAULT mode. spring-boot-app | 2019-05-27 21:50:25.378 INFO 1 --- [ main] .s.d.r.c.RepositoryConfigurationDelegate : Finished Spring Data repository scanning in 205ms. Found 1 repository interfaces. spring-boot-app | 2019-05-27 21:50:26.313 INFO 1 --- [ main] trationDelegate$BeanPostProcessorChecker : Bean 'org.springframework.transaction.annotation.ProxyTransactionManagementConfiguration' of type [org.springframework.transaction.annotation.ProxyTransactionManagementConfiguration$$EnhancerBySpringCGLIB$$e43b97d] is not eligible for getting processed by all BeanPostProcessors (for example: not eligible for auto-proxying) spring-boot-app | 2019-05-27 21:50:27.043 INFO 1 --- [ main] o.s.b.w.embedded.tomcat.TomcatWebServer : Tomcat initialized with port(s): 8080 (http) spring-boot-app | 2019-05-27 21:50:27.195 INFO 1 --- [ main] o.apache.catalina.core.StandardService : Starting service [Tomcat] spring-boot-app | 2019-05-27 21:50:27.196 INFO 1 --- [ main] org.apache.catalina.core.StandardEngine : Starting Servlet engine: [Apache Tomcat/9.0.19] spring-boot-app | 2019-05-27 21:50:27.472 INFO 1 --- [ main] o.a.c.c.C.[Tomcat].[localhost].[/] : Initializing Spring embedded WebApplicationContext spring-boot-app | 2019-05-27 21:50:27.472 INFO 1 --- [ main] o.s.web.context.ContextLoader : Root WebApplicationContext: initialization completed in 4316 ms spring-boot-app | 2019-05-27 21:50:27.928 INFO 1 --- [ main] com.zaxxer.hikari.HikariDataSource : HikariPool-1 - Starting... spring-boot-app | 2019-05-27 21:50:29.226 ERROR 1 --- [ main] com.zaxxer.hikari.pool.HikariPool : HikariPool-1 - Exception during pool initialization. spring-boot-app | spring-boot-app | com.mysql.cj.jdbc.exceptions.CommunicationsException: Communications link failure spring-boot-app | spring-boot-app | The last packet sent successfully to the server was 0 milliseconds ago. The driver has not received any packets from the server. spring-boot-app | at com.mysql.cj.jdbc.exceptions.SQLError.createCommunicationsException(SQLError.java:174) ~[mysql-connector-java-8.0.16.jar!/:8.0.16] spring-boot-app | at com.mysql.cj.jdbc.exceptions.SQLExceptionsMapping.translateException(SQLExceptionsMapping.java:64) ~[mysql-connector-java-8.0.16.jar!/:8.0.16] spring-boot-app | at com.mysql.cj.jdbc.ConnectionImpl.createNewIO(ConnectionImpl.java:835) ~[mysql-connector-java-8.0.16.jar!/:8.0.16] spring-boot-app | at com.mysql.cj.jdbc.ConnectionImpl.<init>(ConnectionImpl.java:455) ~[mysql-connector-java-8.0.16.jar!/:8.0.16] spring-boot-app | at com.mysql.cj.jdbc.ConnectionImpl.getInstance(ConnectionImpl.java:240) ~[mysql-connector-java-8.0.16.jar!/:8.0.16] spring-boot-app | at com.mysql.cj.jdbc.NonRegisteringDriver.connect(NonRegisteringDriver.java:199) ~[mysql-connector-java-8.0.16.jar!/:8.0.16] spring-boot-app | at com.zaxxer.hikari.util.DriverDataSource.getConnection(DriverDataSource.java:136) ~[HikariCP-3.2.0.jar!/:na] spring-boot-app | at com.zaxxer.hikari.pool.PoolBase.newConnection(PoolBase.java:369) ~[HikariCP-3.2.0.jar!/:na] spring-boot-app | at com.zaxxer.hikari.pool.PoolBase.newPoolEntry(PoolBase.java:198) ~[HikariCP-3.2.0.jar!/:na] spring-boot-app | at com.zaxxer.hikari.pool.HikariPool.createPoolEntry(HikariPool.java:467) ~[HikariCP-3.2.0.jar!/:na] spring-boot-app | at com.zaxxer.hikari.pool.HikariPool.checkFailFast(HikariPool.java:541) ~[HikariCP-3.2.0.jar!/:na] spring-boot-app | at com.zaxxer.hikari.pool.HikariPool.<init>(HikariPool.java:115) ~[HikariCP-3.2.0.jar!/:na] spring-boot-app | at com.zaxxer.hikari.HikariDataSource.getConnection(HikariDataSource.java:112) ~[HikariCP-3.2.0.jar!/:na] spring-boot-app | at org.springframework.jdbc.datasource.DataSourceUtils.fetchConnection(DataSourceUtils.java:157) ~[spring-jdbc-5.1.7.RELEASE.jar!/:5.1.7.RELEASE] spring-boot-app | at org.springframework.jdbc.datasource.DataSourceUtils.doGetConnection(DataSourceUtils.java:115) ~[spring-jdbc-5.1.7.RELEASE.jar!/:5.1.7.RELEASE] spring-boot-app | at org.springframework.jdbc.datasource.DataSourceUtils.getConnection(DataSourceUtils.java:78) ~[spring-jdbc-5.1.7.RELEASE.jar!/:5.1.7.RELEASE] spring-boot-app | at org.springframework.jdbc.support.JdbcUtils.extractDatabaseMetaData(JdbcUtils.java:319) ~[spring-jdbc-5.1.7.RELEASE.jar!/:5.1.7.RELEASE] spring-boot-app | at org.springframework.jdbc.support.JdbcUtils.extractDatabaseMetaData(JdbcUtils.java:356) ~[spring-jdbc-5.1.7.RELEASE.jar!/:5.1.7.RELEASE] spring-boot-app | at org.springframework.boot.autoconfigure.orm.jpa.DatabaseLookup.getDatabase(DatabaseLookup.java:73) ~[spring-boot-autoconfigure-2.1.5.RELEASE.jar!/:2.1.5.RELEASE] spring-boot-app | at org.springframework.boot.autoconfigure.orm.jpa.JpaProperties.determineDatabase(JpaProperties.java:142) ~[spring-boot-autoconfigure-2.1.5.RELEASE.jar!/:2.1.5.RELEASE] spring-boot-app | at org.springframework.boot.autoconfigure.orm.jpa.JpaBaseConfiguration.jpaVendorAdapter(JpaBaseConfiguration.java:113) ~[spring-boot-autoconfigure-2.1.5.RELEASE.jar!/:2.1.5.RELEASE] spring-boot-app | at org.springframework.boot.autoconfigure.orm.jpa.HibernateJpaConfiguration$$EnhancerBySpringCGLIB$$2d1a7bec.CGLIB$jpaVendorAdapter$5(<generated>) ~[spring-boot-autoconfigure-2.1.5.RELEASE.jar!/:2.1.5.RELEASE] spring-boot-app | at org.springframework.boot.autoconfigure.orm.jpa.HibernateJpaConfiguration$$EnhancerBySpringCGLIB$$2d1a7bec$$FastClassBySpringCGLIB$$cb57d9da.invoke(<generated>) ~[spring-boot-autoconfigure-2.1.5.RELEASE.jar!/:2.1.5.RELEASE] spring-boot-app | at org.springframework.cglib.proxy.MethodProxy.invokeSuper(MethodProxy.java:244) ~[spring-core-5.1.7.RELEASE.jar!/:5.1.7.RELEASE] spring-boot-app | at org.springframework.context.annotation.ConfigurationClassEnhancer$BeanMethodInterceptor.intercept(ConfigurationClassEnhancer.java:363) ~[spring-context-5.1.7.RELEASE.jar!/:5.1.7.RELEASE] spring-boot-app | at org.springframework.boot.autoconfigure.orm.jpa.HibernateJpaConfiguration$$EnhancerBySpringCGLIB$$2d1a7bec.jpaVendorAdapter(<generated>) ~[spring-boot-autoconfigure-2.1.5.RELEASE.jar!/:2.1.5.RELEASE] spring-boot-app | at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[na:na] spring-boot-app | at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[na:na] spring-boot-app | at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[na:na] spring-boot-app | at java.base/java.lang.reflect.Method.invoke(Method.java:566) ~[na:na] spring-boot-app | at org.springframework.beans.factory.support.SimpleInstantiationStrategy.instantiate(SimpleInstantiationStrategy.java:154) ~[spring-beans-5.1.7.RELEASE.jar!/:5.1.7.RELEASE] spring-boot-app | at org.springframework.beans.factory.support.ConstructorResolver.instantiate(ConstructorResolver.java:622) ~[spring-beans-5.1.7.RELEASE.jar!/:5.1.7.RELEASE] spring-boot-app | at org.springframework.beans.factory.support.ConstructorResolver.instantiateUsingFactoryMethod(ConstructorResolver.java:456) ~[spring-beans-5.1.7.RELEASE.jar!/:5.1.7.RELEASE] spring-boot-app | at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.instantiateUsingFactoryMethod(AbstractAutowireCapableBeanFactory.java:1321) ~[spring-beans-5.1.7.RELEASE.jar!/:5.1.7.RELEASE] spring-boot-app | at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBeanInstance(AbstractAutowireCapableBeanFactory.java:1160) ~[spring-beans-5.1.7.RELEASE.jar!/:5.1.7.RELEASE] spring-boot-app | at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:555) ~[spring-beans-5.1.7.RELEASE.jar!/:5.1.7.RELEASE] spring-boot-app | at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:515) ~[spring-beans-5.1.7.RELEASE.jar!/:5.1.7.RELEASE] spring-boot-app | at org.springframework.beans.factory.support.AbstractBeanFactory.lambda$doGetBean$0(AbstractBeanFactory.java:320) ~[spring-beans-5.1.7.RELEASE.jar!/:5.1.7.RELEASE] spring-boot-app | at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:222) ~[spring-beans-5.1.7.RELEASE.jar!/:5.1.7.RELEASE] spring-boot-app | at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:318) ~[spring-beans-5.1.7.RELEASE.jar!/:5.1.7.RELEASE] spring-boot-app | at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:199) ~[spring-beans-5.1.7.RELEASE.jar!/:5.1.7.RELEASE] spring-boot-app | at org.springframework.beans.factory.config.DependencyDescriptor.resolveCandidate(DependencyDescriptor.java:277) ~[spring-beans-5.1.7.RELEASE.jar!/:5.1.7.RELEASE] spring-boot-app | at org.springframework.beans.factory.support.DefaultListableBeanFactory.doResolveDependency(DefaultListableBeanFactory.java:1248) ~[spring-beans-5.1.7.RELEASE.jar!/:5.1.7.RELEASE] spring-boot-app | at org.springframework.beans.factory.support.DefaultListableBeanFactory.resolveDependency(DefaultListableBeanFactory.java:1168) ~[spring-beans-5.1.7.RELEASE.jar!/:5.1.7.RELEASE] spring-boot-app | at org.springframework.beans.factory.support.ConstructorResolver.resolveAutowiredArgument(ConstructorResolver.java:857) ~[spring-beans-5.1.7.RELEASE.jar!/:5.1.7.RELEASE] spring-boot-app | at org.springframework.beans.factory.support.ConstructorResolver.createArgumentArray(ConstructorResolver.java:760) ~[spring-beans-5.1.7.RELEASE.jar!/:5.1.7.RELEASE] spring-boot-app | at org.springframework.beans.factory.support.ConstructorResolver.instantiateUsingFactoryMethod(ConstructorResolver.java:509) ~[spring-beans-5.1.7.RELEASE.jar!/:5.1.7.RELEASE] spring-boot-app | at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.instantiateUsingFactoryMethod(AbstractAutowireCapableBeanFactory.java:1321) ~[spring-beans-5.1.7.RELEASE.jar!/:5.1.7.RELEASE] spring-boot-app | at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBeanInstance(AbstractAutowireCapableBeanFactory.java:1160) ~[spring-beans-5.1.7.RELEASE.jar!/:5.1.7.RELEASE] spring-boot-app | at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:555) ~[spring-beans-5.1.7.RELEASE.jar!/:5.1.7.RELEASE] spring-boot-app | at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:515) ~[spring-beans-5.1.7.RELEASE.jar!/:5.1.7.RELEASE] spring-boot-app | at org.springframework.beans.factory.support.AbstractBeanFactory.lambda$doGetBean$0(AbstractBeanFactory.java:320) ~[spring-beans-5.1.7.RELEASE.jar!/:5.1.7.RELEASE] spring-boot-app | at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:222) ~[spring-beans-5.1.7.RELEASE.jar!/:5.1.7.RELEASE] spring-boot-app | at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:318) ~[spring-beans-5.1.7.RELEASE.jar!/:5.1.7.RELEASE] spring-boot-app | at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:199) ~[spring-beans-5.1.7.RELEASE.jar!/:5.1.7.RELEASE] spring-boot-app | at org.springframework.beans.factory.config.DependencyDescriptor.resolveCandidate(DependencyDescriptor.java:277) ~[spring-beans-5.1.7.RELEASE.jar!/:5.1.7.RELEASE] spring-boot-app | at org.springframework.beans.factory.support.DefaultListableBeanFactory.doResolveDependency(DefaultListableBeanFactory.java:1248) ~[spring-beans-5.1.7.RELEASE.jar!/:5.1.7.RELEASE] spring-boot-app | at org.springframework.beans.factory.support.DefaultListableBeanFactory.resolveDependency(DefaultListableBeanFactory.java:1168) ~[spring-beans-5.1.7.RELEASE.jar!/:5.1.7.RELEASE] spring-boot-app | at org.springframework.beans.factory.support.ConstructorResolver.resolveAutowiredArgument(ConstructorResolver.java:857) ~[spring-beans-5.1.7.RELEASE.jar!/:5.1.7.RELEASE] spring-boot-app | at org.springframework.beans.factory.support.ConstructorResolver.createArgumentArray(ConstructorResolver.java:760) ~[spring-beans-5.1.7.RELEASE.jar!/:5.1.7.RELEASE] spring-boot-app | at org.springframework.beans.factory.support.ConstructorResolver.instantiateUsingFactoryMethod(ConstructorResolver.java:509) ~[spring-beans-5.1.7.RELEASE.jar!/:5.1.7.RELEASE] spring-boot-app | at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.instantiateUsingFactoryMethod(AbstractAutowireCapableBeanFactory.java:1321) ~[spring-beans-5.1.7.RELEASE.jar!/:5.1.7.RELEASE] spring-boot-app | at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBeanInstance(AbstractAutowireCapableBeanFactory.java:1160) ~[spring-beans-5.1.7.RELEASE.jar!/:5.1.7.RELEASE] spring-boot-app | at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:555) ~[spring-beans-5.1.7.RELEASE.jar!/:5.1.7.RELEASE] spring-boot-app | at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:515) ~[spring-beans-5.1.7.RELEASE.jar!/:5.1.7.RELEASE] spring-boot-app | at org.springframework.beans.factory.support.AbstractBeanFactory.lambda$doGetBean$0(AbstractBeanFactory.java:320) ~[spring-beans-5.1.7.RELEASE.jar!/:5.1.7.RELEASE] spring-boot-app | at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:222) ~[spring-beans-5.1.7.RELEASE.jar!/:5.1.7.RELEASE] spring-boot-app | at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:318) ~[spring-beans-5.1.7.RELEASE.jar!/:5.1.7.RELEASE] spring-boot-app | at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:199) ~[spring-beans-5.1.7.RELEASE.jar!/:5.1.7.RELEASE] spring-boot-app | at org.springframework.context.support.AbstractApplicationContext.getBean(AbstractApplicationContext.java:1105) ~[spring-context-5.1.7.RELEASE.jar!/:5.1.7.RELEASE] spring-boot-app | at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:867) ~[spring-context-5.1.7.RELEASE.jar!/:5.1.7.RELEASE] spring-boot-app | at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:549) ~[spring-context-5.1.7.RELEASE.jar!/:5.1.7.RELEASE] spring-boot-app | at org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.refresh(ServletWebServerApplicationContext.java:142) ~[spring-boot-2.1.5.RELEASE.jar!/:2.1.5.RELEASE] spring-boot-app | at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:775) ~[spring-boot-2.1.5.RELEASE.jar!/:2.1.5.RELEASE] spring-boot-app | at org.springframework.boot.SpringApplication.refreshContext(SpringApplication.java:397) ~[spring-boot-2.1.5.RELEASE.jar!/:2.1.5.RELEASE] spring-boot-app | at org.springframework.boot.SpringApplication.run(SpringApplication.java:316) ~[spring-boot-2.1.5.RELEASE.jar!/:2.1.5.RELEASE] spring-boot-app | at org.springframework.boot.SpringApplication.run(SpringApplication.java:1260) ~[spring-boot-2.1.5.RELEASE.jar!/:2.1.5.RELEASE] spring-boot-app | at org.springframework.boot.SpringApplication.run(SpringApplication.java:1248) ~[spring-boot-2.1.5.RELEASE.jar!/:2.1.5.RELEASE] spring-boot-app | at com.jv.demo.DemoApplication.main(DemoApplication.java:10) ~[classes!/:0.0.1-SNAPSHOT] spring-boot-app | at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[na:na] spring-boot-app | at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[na:na] spring-boot-app | at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[na:na] spring-boot-app | at java.base/java.lang.reflect.Method.invoke(Method.java:566) ~[na:na] spring-boot-app | at org.springframework.boot.loader.MainMethodRunner.run(MainMethodRunner.java:48) ~[spring-boot-app.jar:0.0.1-SNAPSHOT] spring-boot-app | at org.springframework.boot.loader.Launcher.launch(Launcher.java:87) ~[spring-boot-app.jar:0.0.1-SNAPSHOT] spring-boot-app | at org.springframework.boot.loader.Launcher.launch(Launcher.java:50) ~[spring-boot-app.jar:0.0.1-SNAPSHOT] spring-boot-app | at org.springframework.boot.loader.JarLauncher.main(JarLauncher.java:51) ~[spring-boot-app.jar:0.0.1-SNAPSHOT] spring-boot-app | Caused by: com.mysql.cj.exceptions.CJCommunicationsException: Communications link failure spring-boot-app | spring-boot-app | The last packet sent successfully to the server was 0 milliseconds ago. The driver has not received any packets from the server. spring-boot-app | at java.base/jdk.internal.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method) ~[na:na] spring-boot-app | at java.base/jdk.internal.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62) ~[na:na] spring-boot-app | at java.base/jdk.internal.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45) ~[na:na] spring-boot-app | at java.base/java.lang.reflect.Constructor.newInstance(Constructor.java:490) ~[na:na] spring-boot-app | at com.mysql.cj.exceptions.ExceptionFactory.createException(ExceptionFactory.java:61) ~[mysql-connector-java-8.0.16.jar!/:8.0.16] spring-boot-app | at com.mysql.cj.exceptions.ExceptionFactory.createException(ExceptionFactory.java:105) ~[mysql-connector-java-8.0.16.jar!/:8.0.16] spring-boot-app | at com.mysql.cj.exceptions.ExceptionFactory.createException(ExceptionFactory.java:151) ~[mysql-connector-java-8.0.16.jar!/:8.0.16] spring-boot-app | at com.mysql.cj.exceptions.ExceptionFactory.createCommunicationsException(ExceptionFactory.java:167) ~[mysql-connector-java-8.0.16.jar!/:8.0.16] spring-boot-app | at com.mysql.cj.protocol.a.NativeSocketConnection.connect(NativeSocketConnection.java:91) ~[mysql-connector-java-8.0.16.jar!/:8.0.16] spring-boot-app | at com.mysql.cj.NativeSession.connect(NativeSession.java:152) ~[mysql-connector-java-8.0.16.jar!/:8.0.16] spring-boot-app | at com.mysql.cj.jdbc.ConnectionImpl.connectOneTryOnly(ConnectionImpl.java:955) ~[mysql-connector-java-8.0.16.jar!/:8.0.16] spring-boot-app | at com.mysql.cj.jdbc.ConnectionImpl.createNewIO(ConnectionImpl.java:825) ~[mysql-connector-java-8.0.16.jar!/:8.0.16] spring-boot-app | ... 84 common frames omitted spring-boot-app | Caused by: java.net.ConnectException: Connection refused (Connection refused) spring-boot-app | at java.base/java.net.PlainSocketImpl.socketConnect(Native Method) ~[na:na] spring-boot-app | at java.base/java.net.AbstractPlainSocketImpl.doConnect(AbstractPlainSocketImpl.java:399) ~[na:na] spring-boot-app | at java.base/java.net.AbstractPlainSocketImpl.connectToAddress(AbstractPlainSocketImpl.java:242) ~[na:na] spring-boot-app | at java.base/java.net.AbstractPlainSocketImpl.connect(AbstractPlainSocketImpl.java:224) ~[na:na] spring-boot-app | at java.base/java.net.SocksSocketImpl.connect(SocksSocketImpl.java:403) ~[na:na] spring-boot-app | at java.base/java.net.Socket.connect(Socket.java:591) ~[na:na] spring-boot-app | at com.mysql.cj.protocol.StandardSocketFactory.connect(StandardSocketFactory.java:155) ~[mysql-connector-java-8.0.16.jar!/:8.0.16] spring-boot-app | at com.mysql.cj.protocol.a.NativeSocketConnection.connect(NativeSocketConnection.java:65) ~[mysql-connector-java-8.0.16.jar!/:8.0.16] spring-boot-app | ... 87 common frames omitted spring-boot-app | spring-boot-app | 2019-05-27 21:50:29.234 WARN 1 --- [ main] o.s.b.a.orm.jpa.DatabaseLookup : Unable to determine jdbc url from datasource spring-boot-app | spring-boot-app | org.springframework.jdbc.support.MetaDataAccessException: Could not get Connection for extracting meta-data; nested exception is org.springframework.jdbc.CannotGetJdbcConnectionException: Failed to obtain JDBC Connection; nested exception is com.mysql.cj.jdbc.exceptions.CommunicationsException: Communications link failure
由于您的Spring Boot应用程序也在docker映像中启动，因此您无法使用docker公开的端口，而需要使用映像的原始端口。
在application.properties您需要使用：
application.properties
spring.datasource.url = jdbc:mysql://mysql:3306/db
