2023-07-30 13:32:11.139 ERROR 25274 --- [ main] com.zaxxer.hikari.pool.HikariPool : HikariPool-1 - Exception during pool initialization. com.mysql.cj.jdbc.exceptions.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. at com.mysql.cj.jdbc.exceptions.SQLError.createCommunicationsException(SQLError.java:174) ~[mysql-connector-java-8.0.15.jar!/:8.0.15] at com.mysql.cj.jdbc.exceptions.SQLExceptionsMapping.translateException(SQLExceptionsMapping.java:64) ~[mysql-connector-java-8.0.15.jar!/:8.0.15] at com.mysql.cj.jdbc.ConnectionImpl.createNewIO(ConnectionImpl.java:835) ~[mysql-connector-java-8.0.15.jar!/:8.0.15] at com.mysql.cj.jdbc.ConnectionImpl.<init>(ConnectionImpl.java:455) ~[mysql-connector-java-8.0.15.jar!/:8.0.15] at com.mysql.cj.jdbc.ConnectionImpl.getInstance(ConnectionImpl.java:240) ~[mysql-connector-java-8.0.15.jar!/:8.0.15] at com.mysql.cj.jdbc.NonRegisteringDriver.connect(NonRegisteringDriver.java:199) ~[mysql-connector-java-8.0.15.jar!/:8.0.15] at com.zaxxer.hikari.util.DriverDataSource.getConnection(DriverDataSource.java:138) ~[HikariCP-4.0.3.jar!/:na] at com.zaxxer.hikari.pool.PoolBase.newConnection(PoolBase.java:364) ~[HikariCP-4.0.3.jar!/:na] at com.zaxxer.hikari.pool.PoolBase.newPoolEntry(PoolBase.java:206) ~[HikariCP-4.0.3.jar!/:na] at com.zaxxer.hikari.pool.HikariPool.createPoolEntry(HikariPool.java:476) [HikariCP-4.0.3.jar!/:na] at com.zaxxer.hikari.pool.HikariPool.checkFailFast(HikariPool.java:561) [HikariCP-4.0.3.jar!/:na] at com.zaxxer.hikari.pool.HikariPool.<init>(HikariPool.java:115) [HikariCP-4.0.3.jar!/:na] at com.zaxxer.hikari.HikariDataSource.getConnection(HikariDataSource.java:112) [HikariCP-4.0.3.jar!/:na] at org.hibernate.engine.jdbc.connections.internal.DatasourceConnectionProviderImpl.getConnection(DatasourceConnectionProviderImpl.java:122) [hibernate-core-5.6.15.Final.jar!/:5.6.15.Final] at org.hibernate.engine.jdbc.env.internal.JdbcEnvironmentInitiator$ConnectionProviderJdbcConnectionAccess.obtainConnection(JdbcEnvironmentInitiator.java:181) [hibernate-core-5.6.15.Final.jar!/:5.6.15.Final] at org.hibernate.engine.jdbc.env.internal.JdbcEnvironmentInitiator.initiateService(JdbcEnvironmentInitiator.java:68) [hibernate-core-5.6.15.Final.jar!/:5.6.15.Final] at org.hibernate.engine.jdbc.env.internal.JdbcEnvironmentInitiator.initiateService(JdbcEnvironmentInitiator.java:35) [hibernate-core-5.6.15.Final.jar!/:5.6.15.Final] at org.hibernate.boot.registry.internal.StandardServiceRegistryImpl.initiateService(StandardServiceRegistryImpl.java:101) [hibernate-core-5.6.15.Final.jar!/:5.6.15.Final] at org.hibernate.service.internal.AbstractServiceRegistryImpl.createService(AbstractServiceRegistryImpl.java:272) [hibernate-core-5.6.15.Final.jar!/:5.6.15.Final] at org.hibernate.service.internal.AbstractServiceRegistryImpl.initializeService(AbstractServiceRegistryImpl.java:246) [hibernate-core-5.6.15.Final.jar!/:5.6.15.Final] at org.hibernate.service.internal.AbstractServiceRegistryImpl.getService(AbstractServiceRegistryImpl.java:223) [hibernate-core-5.6.15.Final.jar!/:5.6.15.Final] at org.hibernate.id.factory.internal.DefaultIdentifierGeneratorFactory.injectServices(DefaultIdentifierGeneratorFactory.java:175) [hibernate-core-5.6.15.Final.jar!/:5.6.15.Final] at org.hibernate.service.internal.AbstractServiceRegistryImpl.injectDependencies(AbstractServiceRegistryImpl.java:295) [hibernate-core-5.6.15.Final.jar!/:5.6.15.Final] at org.hibernate.service.internal.AbstractServiceRegistryImpl.initializeService(AbstractServiceRegistryImpl.java:252) [hibernate-core-5.6.15.Final.jar!/:5.6.15.Final] at org.hibernate.service.internal.AbstractServiceRegistryImpl.getService(AbstractServiceRegistryImpl.java:223) [hibernate-core-5.6.15.Final.jar!/:5.6.15.Final] at org.hibernate.boot.internal.InFlightMetadataCollectorImpl.<init>(InFlightMetadataCollectorImpl.java:173) [hibernate-core-5.6.15.Final.jar!/:5.6.15.Final] at org.hibernate.boot.model.process.spi.MetadataBuildingProcess.complete(MetadataBuildingProcess.java:127) [hibernate-core-5.6.15.Final.jar!/:5.6.15.Final] at org.hibernate.jpa.boot.internal.EntityManagerFactoryBuilderImpl.metadata(EntityManagerFactoryBuilderImpl.java:1460) [hibernate-core-5.6.15.Final.jar!/:5.6.15.Final] at org.hibernate.jpa.boot.internal.EntityManagerFactoryBuilderImpl.build(EntityManagerFactoryBuilderImpl.java:1494) [hibernate-core-5.6.15.Final.jar!/:5.6.15.Final] at org.springframework.orm.jpa.vendor.SpringHibernateJpaPersistenceProvider.createContainerEntityManagerFactory(SpringHibernateJpaPersistenceProvider.java:58) [spring-orm-5.3.27.jar!/:5.3.27] at org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean.createNativeEntityManagerFactory(LocalContainerEntityManagerFactoryBean.java:365) [spring-orm-5.3.27.jar!/:5.3.27] at org.springframework.orm.jpa.AbstractEntityManagerFactoryBean.buildNativeEntityManagerFactory(AbstractEntityManagerFactoryBean.java:409) [spring-orm-5.3.27.jar!/:5.3.27] at org.springframework.orm.jpa.AbstractEntityManagerFactoryBean.afterPropertiesSet(AbstractEntityManagerFactoryBean.java:396) [spring-orm-5.3.27.jar!/:5.3.27] at org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean.afterPropertiesSet(LocalContainerEntityManagerFactoryBean.java:341) [spring-orm-5.3.27.jar!/:5.3.27] at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.invokeInitMethods(AbstractAutowireCapableBeanFactory.java:1863) [spring-beans-5.3.27.jar!/:5.3.27] at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1800) [spring-beans-5.3.27.jar!/:5.3.27] at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:620) [spring-beans-5.3.27.jar!/:5.3.27] at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:542) [spring-beans-5.3.27.jar!/:5.3.27] at org.springframework.beans.factory.support.AbstractBeanFactory.lambda$doGetBean$0(AbstractBeanFactory.java:335) [spring-beans-5.3.27.jar!/:5.3.27] at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:234) ~[spring-beans-5.3.27.jar!/:5.3.27] at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:333) [spring-beans-5.3.27.jar!/:5.3.27] at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:208) [spring-beans-5.3.27.jar!/:5.3.27] at org.springframework.context.support.AbstractApplicationContext.getBean(AbstractApplicationContext.java:1156) ~[spring-context-5.3.27.jar!/:5.3.27] at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:910) ~[spring-context-5.3.27.jar!/:5.3.27] at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:583) ~[spring-context-5.3.27.jar!/:5.3.27] at org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.refresh(ServletWebServerApplicationContext.java:147) ~[spring-boot-2.7.12.jar!/:2.7.12]
现在想用个最简单jar文件试试。。
一些背景:
我远程有mysql5.7, jdk1.8,tomcat,
本地新建远程的数据库表,查询,插入,连接都OK,
完了,打包个jar丢远程后, 运行Java -jar, 就是如上报错信息。
根据报错信息显示,问题出现在与 MySQL 数据库的通信过程中。具体错误是 "Communications link failure",意味着无法建立到数据库服务器的连接。
这可能是由于以下几个原因引起的:
数据库服务器地址或端口错误:请确保在连接数据库时提供了正确的数据库服务器地址和端口号。
数据库服务器未运行:请确保数据库服务器已经启动,并且可以通过远程服务器访问。
防火墙或网络配置限制:请检查防火墙或网络配置,确保允许远程服务器连接到数据库服务器的地址和端口。
数据库访问凭据错误:请确认在连接数据库时提供了正确的用户名和密码,并且该用户具有足够的权限来访问数据库。
缺少必要的数据库驱动程序:根据报错信息推测,你使用的是 MySQL 数据库,所以请确保在项目中包含了正确的 MySQL 驱动程序(例如 mysql-connector-java)。可以检查一下是否已经将 mysql-connector-java-8.0.15.jar 包含在你的项目中。如果没有,可以从 MySQL 官网下载并添加到你的项目中。
解决此问题的方法可能因具体情况而异,但以上列出的几个原因是最常见的。你可以根据这些提示尝试解决问题。
感谢关注,工作忙,才打开电脑...
你提供的帮助条目会去逐条确认,
我补充了问题的一些背景。
连不上数据库
这不很明显?在服务器上测一下db
telnet一下数据库服务器,感觉不通