连接链接失败 MySQL

Posted 2023-02-26

【中文标题】连接链接失败 MySQL

【英文标题】：Connect link failure MySQL

【发布时间】：2019-03-01 13:09:33

【问题描述】：

我的项目正在部署 Spring Boot + REST。 应用程序需要有使用 mysql 的数据库。 我的应用程序有 apache tomcat 9.0.12 版本。 我尝试构建作为 java 应用程序运行，并且系统报告错误消息：

    2018-09-25 23:14:23.398  INFO 21112 --- [ost-startStop-1] o.s.web.context.ContextLoader            : Root WebApplicationContext: initialization completed in 8286 ms
2018-09-25 23:14:23.897  INFO 21112 --- [ost-startStop-1] o.s.b.w.servlet.ServletRegistrationBean  : Mapping servlet: 'dispatcherServlet' to [/]
2018-09-25 23:14:23.905  INFO 21112 --- [ost-startStop-1] o.s.b.w.servlet.FilterRegistrationBean   : Mapping filter: 'characterEncodingFilter' to: [/*]
2018-09-25 23:14:23.907  INFO 21112 --- [ost-startStop-1] o.s.b.w.servlet.FilterRegistrationBean   : Mapping filter: 'hiddenHttpMethodFilter' to: [/*]
2018-09-25 23:14:23.907  INFO 21112 --- [ost-startStop-1] o.s.b.w.servlet.FilterRegistrationBean   : Mapping filter: 'httpPutFormContentFilter' to: [/*]
2018-09-25 23:14:23.907  INFO 21112 --- [ost-startStop-1] o.s.b.w.servlet.FilterRegistrationBean   : Mapping filter: 'requestContextFilter' to: [/*]
2018-09-25 23:14:27.248 ERROR 21112 --- [  restartedMain] o.a.tomcat.jdbc.pool.ConnectionPool      : 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.
    at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method) ~[na:1.8.0_181]
    at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62) ~[na:1.8.0_181]
    at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45) ~[na:1.8.0_181]
    at java.lang.reflect.Constructor.newInstance(Constructor.java:423) ~[na:1.8.0_181]
    at com.mysql.jdbc.Util.handleNewInstance(Util.java:425) ~[mysql-connector-java-5.1.42.jar:5.1.42]
    at com.mysql.jdbc.SQLError.createCommunicationsException(SQLError.java:989) ~[mysql-connector-java-5.1.42.jar:5.1.42]
    at com.mysql.jdbc.MysqlIO.<init>(MysqlIO.java:341) ~[mysql-connector-java-5.1.42.jar:5.1.42]
    at com.mysql.jdbc.ConnectionImpl.coreConnect(ConnectionImpl.java:2192) ~[mysql-connector-java-5.1.42.jar:5.1.42]
    at com.mysql.jdbc.ConnectionImpl.connectOneTryOnly(ConnectionImpl.java:2225) ~[mysql-connector-java-5.1.42.jar:5.1.42]
    at com.mysql.jdbc.ConnectionImpl.createNewIO(ConnectionImpl.java:2024) ~[mysql-connector-java-5.1.42.jar:5.1.42]
    at com.mysql.jdbc.ConnectionImpl.<init>(ConnectionImpl.java:779) ~[mysql-connector-java-5.1.42.jar:5.1.42]
    at com.mysql.jdbc.JDBC4Connection.<init>(JDBC4Connection.java:47) ~[mysql-connector-java-5.1.42.jar:5.1.42]
    at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method) ~[na:1.8.0_181]
    at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62) ~[na:1.8.0_181]
    at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45) ~[na:1.8.0_181]
    at java.lang.reflect.Constructor.newInstance(Constructor.java:423) ~[na:1.8.0_181]
    at com.mysql.jdbc.Util.handleNewInstance(Util.java:425) ~[mysql-connector-java-5.1.42.jar:5.1.42]
    at com.mysql.jdbc.ConnectionImpl.getInstance(ConnectionImpl.java:389) ~[mysql-connector-java-5.1.42.jar:5.1.42]
    at com.mysql.jdbc.NonRegisteringDriver.connect(NonRegisteringDriver.java:330) ~[mysql-connector-java-5.1.42.jar:5.1.42]
    at org.apache.tomcat.jdbc.pool.PooledConnection.connectUsingDriver(PooledConnection.java:310) ~[tomcat-jdbc-8.5.15.jar:na]
    at org.apache.tomcat.jdbc.pool.PooledConnection.connect(PooledConnection.java:203) ~[tomcat-jdbc-8.5.15.jar:na]
    at org.apache.tomcat.jdbc.pool.ConnectionPool.createConnection(ConnectionPool.java:735) [tomcat-jdbc-8.5.15.jar:na]
    at org.apache.tomcat.jdbc.pool.ConnectionPool.borrowConnection(ConnectionPool.java:667) [tomcat-jdbc-8.5.15.jar:na]
    at org.apache.tomcat.jdbc.pool.ConnectionPool.init(ConnectionPool.java:482) [tomcat-jdbc-8.5.15.jar:na]
    at org.apache.tomcat.jdbc.pool.ConnectionPool.<init>(ConnectionPool.java:154) [tomcat-jdbc-8.5.15.jar:na]
    at org.apache.tomcat.jdbc.pool.DataSourceProxy.pCreatePool(DataSourceProxy.java:118) [tomcat-jdbc-8.5.15.jar:na]
    at org.apache.tomcat.jdbc.pool.DataSourceProxy.createPool(DataSourceProxy.java:107) [tomcat-jdbc-8.5.15.jar:na]
    at org.apache.tomcat.jdbc.pool.DataSourceProxy.getConnection(DataSourceProxy.java:131) [tomcat-jdbc-8.5.15.jar:na]
    at org.springframework.jdbc.datasource.DataSourceUtils.doGetConnection(DataSourceUtils.java:111) [spring-jdbc-4.3.9.RELEASE.jar:4.3.9.RELEASE]
    at org.springframework.jdbc.datasource.DataSourceUtils.getConnection(DataSourceUtils.java:77) [spring-jdbc-4.3.9.RELEASE.jar:4.3.9.RELEASE]
    at org.springframework.jdbc.support.JdbcUtils.extractDatabaseMetaData(JdbcUtils.java:326) [spring-jdbc-4.3.9.RELEASE.jar:4.3.9.RELEASE]
    at org.springframework.jdbc.support.JdbcUtils.extractDatabaseMetaData(JdbcUtils.java:366) [spring-jdbc-4.3.9.RELEASE.jar:4.3.9.RELEASE]
    at org.springframework.boot.autoconfigure.orm.jpa.DatabaseLookup.getDatabase(DatabaseLookup.java:72) [spring-boot-autoconfigure-1.5.4.RELEASE.jar:1.5.4.RELEASE]
    at org.springframework.boot.autoconfigure.orm.jpa.JpaProperties.determineDatabase(JpaProperties.java:139) [spring-boot-autoconfigure-1.5.4.RELEASE.jar:1.5.4.RELEASE]
    at org.springframework.boot.autoconfigure.orm.jpa.JpaBaseConfiguration.jpaVendorAdapter(JpaBaseConfiguration.java:105) [spring-boot-autoconfigure-1.5.4.RELEASE.jar:1.5.4.RELEASE]
    at org.springframework.boot.autoconfigure.orm.jpa.HibernateJpaAutoConfiguration$$EnhancerBySpringCGLIB$$c22a218.CGLIB$jpaVendorAdapter$10(<generated>) [spring-boot-autoconfigure-1.5.4.RELEASE.jar:1.5.4.RELEASE]
    at org.springframework.boot.autoconfigure.orm.jpa.HibernateJpaAutoConfiguration$$EnhancerBySpringCGLIB$$c22a218$$FastClassBySpringCGLIB$$938fdb3d.invoke(<generated>) [spring-boot-autoconfigure-1.5.4.RELEASE.jar:1.5.4.RELEASE]
    at org.springframework.cglib.proxy.MethodProxy.invokeSuper(MethodProxy.java:228) [spring-core-4.3.9.RELEASE.jar:4.3.9.RELEASE]
    at org.springframework.context.annotation.ConfigurationClassEnhancer$BeanMethodInterceptor.intercept(ConfigurationClassEnhancer.java:358) [spring-context-4.3.9.RELEASE.jar:4.3.9.RELEASE]
    at org.springframework.boot.autoconfigure.orm.jpa.HibernateJpaAutoConfiguration$$EnhancerBySpringCGLIB$$c22a218.jpaVendorAdapter(<generated>) [spring-boot-autoconfigure-1.5.4.RELEASE.jar:1.5.4.RELEASE]
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[na:1.8.0_181]
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[na:1.8.0_181]
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[na:1.8.0_181]
    at java.lang.reflect.Method.invoke(Method.java:498) ~[na:1.8.0_181]
    at org.springframework.beans.factory.support.SimpleInstantiationStrategy.instantiate(SimpleInstantiationStrategy.java:162) [spring-beans-4.3.9.RELEASE.jar:4.3.9.RELEASE]
    at org.springframework.beans.factory.support.ConstructorResolver.instantiateUsingFactoryMethod(ConstructorResolver.java:588) [spring-beans-4.3.9.RELEASE.jar:4.3.9.RELEASE]
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.instantiateUsingFactoryMethod(AbstractAutowireCapableBeanFactory.java:1173) [spring-beans-4.3.9.RELEASE.jar:4.3.9.RELEASE]
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBeanInstance(AbstractAutowireCapableBeanFactory.java:1067) [spring-beans-4.3.9.RELEASE.jar:4.3.9.RELEASE]
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:513) [spring-beans-4.3.9.RELEASE.jar:4.3.9.RELEASE]
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:483) [spring-beans-4.3.9.RELEASE.jar:4.3.9.RELEASE]
    at org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:306) [spring-beans-4.3.9.RELEASE.jar:4.3.9.RELEASE]
    at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:230) [spring-beans-4.3.9.RELEASE.jar:4.3.9.RELEASE]
    at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:302) [spring-beans-4.3.9.RELEASE.jar:4.3.9.RELEASE]
    at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:202) [spring-beans-4.3.9.RELEASE.jar:4.3.9.RELEASE]
    at org.springframework.beans.factory.config.DependencyDescriptor.resolveCandidate(DependencyDescriptor.java:208) [spring-beans-4.3.9.RELEASE.jar:4.3.9.RELEASE]
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.doResolveDependency(DefaultListableBeanFactory.java:1138) [spring-beans-4.3.9.RELEASE.jar:4.3.9.RELEASE]
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.resolveDependency(DefaultListableBeanFactory.java:1066) [spring-beans-4.3.9.RELEASE.jar:4.3.9.RELEASE]
    at org.springframework.beans.factory.support.ConstructorResolver.resolveAutowiredArgument(ConstructorResolver.java:835) [spring-beans-4.3.9.RELEASE.jar:4.3.9.RELEASE]
    at org.springframework.beans.factory.support.ConstructorResolver.createArgumentArray(ConstructorResolver.java:741) [spring-beans-4.3.9.RELEASE.jar:4.3.9.RELEASE]
    at org.springframework.beans.factory.support.ConstructorResolver.instantiateUsingFactoryMethod(ConstructorResolver.java:467) [spring-beans-4.3.9.RELEASE.jar:4.3.9.RELEASE]
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.instantiateUsingFactoryMethod(AbstractAutowireCapableBeanFactory.java:1173) [spring-beans-4.3.9.RELEASE.jar:4.3.9.RELEASE]
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBeanInstance(AbstractAutowireCapableBeanFactory.java:1067) [spring-beans-4.3.9.RELEASE.jar:4.3.9.RELEASE]
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:513) [spring-beans-4.3.9.RELEASE.jar:4.3.9.RELEASE]
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:483) [spring-beans-4.3.9.RELEASE.jar:4.3.9.RELEASE]
    at org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:306) [spring-beans-4.3.9.RELEASE.jar:4.3.9.RELEASE]
    at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:230) [spring-beans-4.3.9.RELEASE.jar:4.3.9.RELEASE]
    at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:302) [spring-beans-4.3.9.RELEASE.jar:4.3.9.RELEASE]
    at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:202) [spring-beans-4.3.9.RELEASE.jar:4.3.9.RELEASE]

行太多...

请告诉我如何将 spring boot 与 DB 连接起来。谢谢。

【问题讨论】：

您的 MySQL 服务器似乎无法访问。它正在运行的主机名/IP 地址是什么？ telnet hostname/IP 3306 的终端输出是什么？

application.properties: ## Spring DATASOURCE (DataSourceAutoConfiguration & DataSourceProperties) spring.datasource.url = jdbc:mysql://localhost:3306/world?useSSL=false spring.datasource.username = root spring .datasource.password = varun123 ## Hibernate Properties # SQL 方言使 Hibernate 为所选数据库生成更好的 SQL spring.jpa.properties.hibernate.dialect = org.hibernate.dialect.MySQL5Dialect # Hibernate ddl auto (create, create-drop , 验证, 更新) spring.jpa.hibernate.ddl-auto = update

你能把输出写到telnet localhost 3306。您的 MySQL 服务器是否已在您的 localhost 上启动并运行？

Cmd 回复：C:\WINDOWS\system32>telnet localhost 3306 Connecting To localhost...无法打开与主机的连接，在端口 3306：连接失败

你没有在你的localhost 上启动并运行你的 MySQL 服务器。启动并运行它，它会工作得很好。而且我不一定会像您的第一条评论那样将我的用户名和密码放在网上。

【参考方案1】：

总结一下cmets：

您的 MySQL 服务器未侦听 localhost 端口 3306 上的连接。你需要安装它，可以找到Windows安装参考here。并给出你的配置：

spring.datasource.url = jdbc:mysql://localhost:3306/world?useSSL=false
spring.datasource.username = root spring.datasource.password = varun123
spring.jpa.properties.hibernate.dialect = org.hibernate.dialect.MySQL5Dialect
spring.jpa.hibernate.ddl-auto = update

您需要创建一个名为world 的数据库，并且密码为varun123 的root 用户将能够访问它。