unable to connect to mysql

[zhaque44]

unable to connect to mysql using yur project, can you help with this:

`Caused by: com.mysql.cj.exceptions.CJCommunicationsException: 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 java.base/jdk.internal.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method) ~[na:na]
at java.base/jdk.internal.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62) ~[na:na]
at java.base/jdk.internal.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45) ~[na:na]
at java.base/java.lang.reflect.Constructor.newInstance(Constructor.java:490) ~[na:na]
at com.mysql.cj.exceptions.ExceptionFactory.createException(ExceptionFactory.java:61) ~[mysql-connector-java-8.0.15.jar:8.0.15]
at com.mysql.cj.exceptions.ExceptionFactory.createException(ExceptionFactory.java:105) ~[mysql-connector-java-8.0.15.jar:8.0.15]
at com.mysql.cj.exceptions.ExceptionFactory.createException(ExceptionFactory.java:151) ~[mysql-connector-java-8.0.15.jar:8.0.15]
at com.mysql.cj.exceptions.ExceptionFactory.createCommunicationsException(ExceptionFactory.java:167) ~[mysql-connector-java-8.0.15.jar:8.0.15]
at com.mysql.cj.protocol.a.NativeSocketConnection.connect(NativeSocketConnection.java:91) ~[mysql-connector-java-8.0.15.jar:8.0.15]
at com.mysql.cj.NativeSession.connect(NativeSession.java:152) ~[mysql-connector-java-8.0.15.jar:8.0.15]
at com.mysql.cj.jdbc.ConnectionImpl.connectOneTryOnly(ConnectionImpl.java:955) ~[mysql-connector-java-8.0.15.jar:8.0.15]
at com.mysql.cj.jdbc.ConnectionImpl.createNewIO(ConnectionImpl.java:825) ~[mysql-connector-java-8.0.15.jar:8.0.15]
... 48 common frames omitted
Caused by: java.net.ConnectException: Connection refused (Connection refused)
at java.base/java.net.PlainSocketImpl.socketConnect(Native Method) ~[na:na]
at java.base/java.net.AbstractPlainSocketImpl.doConnect(AbstractPlainSocketImpl.java:399) ~[na:na]
at java.base/java.net.AbstractPlainSocketImpl.connectToAddress(AbstractPlainSocketImpl.java:242) ~[na:na]
at java.base/java.net.AbstractPlainSocketImpl.connect(AbstractPlainSocketImpl.java:224) ~[na:na]
at java.base/java.net.SocksSocketImpl.connect(SocksSocketImpl.java:392) ~[na:na]
at java.base/java.net.Socket.connect(Socket.java:609) ~[na:na]
at com.mysql.cj.protocol.StandardSocketFactory.connect(StandardSocketFactory.java:155) ~[mysql-connector-java-8.0.15.jar:8.0.15]
at com.mysql.cj.protocol.a.NativeSocketConnection.connect(NativeSocketConnection.java:65) ~[mysql-connector-java-8.0.15.jar:8.0.15]
... 51 common frames omitted

2021-08-25 09:42:30.420 WARN 78834 --- [ main] o.h.engine.jdbc.spi.SqlExceptionHelper : SQL Error: 0, SQLState: 08S01
2021-08-25 09:42:30.420 ERROR 78834 --- [ main] o.h.engine.jdbc.spi.SqlExceptionHelper : 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.
2021-08-25 09:42:30.427 WARN 78834 --- [ main] ConfigServletWebServerApplicationContext : Exception encountered during context initialization - cancelling refresh attempt: org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'entityManagerFactory' defined in class path resource [org/springframework/boot/autoconfigure/orm/jpa/HibernateJpaConfiguration.class]: Invocation of init method failed; nested exception is javax.persistence.PersistenceException: [PersistenceUnit: default] Unable to build Hibernate SessionFactory; nested exception is org.hibernate.exception.JDBCConnectionException: Unable to open JDBC Connection for DDL execution
2021-08-25 09:42:30.428 INFO 78834 --- [ main] o.apache.catalina.core.StandardService : Stopping service [Tomcat]
2021-08-25 09:42:30.439 INFO 78834 --- [ main] ConditionEvaluationReportLoggingListener :

Error starting ApplicationContext. To display the conditions report re-run your application with 'debug' enabled.
2021-08-25 09:42:30.442 ERROR 78834 --- [ main] o.s.boot.SpringApplication : Application run failed

org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'entityManagerFactory' defined in class path resource [org/springframework/boot/autoconfigure/orm/jpa/HibernateJpaConfiguration.class]: Invocation of init method failed; nested exception is javax.persistence.PersistenceException: [PersistenceUnit: default] Unable to build Hibernate SessionFactory; nested exception is org.hibernate.exception.JDBCConnectionException: Unable to open JDBC Connection for DDL execution
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1762) ~[spring-beans-5.1.5.RELEASE.jar:5.1.5.RELEASE]
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:593) ~[spring-beans-5.1.5.RELEASE.jar:5.1.5.RELEASE]
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:515) ~[spring-beans-5.1.5.RELEASE.jar:5.1.5.RELEASE]
at org.springframework.beans.factory.support.AbstractBeanFactory.lambda$doGetBean$0(AbstractBeanFactory.java:320) ~[spring-beans-5.1.5.RELEASE.jar:5.1.5.RELEASE]
at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:222) ~[spring-beans-5.1.5.RELEASE.jar:5.1.5.RELEASE]
at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:318) ~[spring-beans-5.1.5.RELEASE.jar:5.1.5.RELEASE]
at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:199) ~[spring-beans-5.1.5.RELEASE.jar:5.1.5.RELEASE]
at org.springframework.context.support.AbstractApplicationContext.getBean(AbstractApplicationContext.java:1105) ~[spring-context-5.1.5.RELEASE.jar:5.1.5.RELEASE]
at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:867) ~[spring-context-5.1.5.RELEASE.jar:5.1.5.RELEASE]
at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:549) ~[spring-context-5.1.5.RELEASE.jar:5.1.5.RELEASE]
at org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.refresh(ServletWebServerApplicationContext.java:142) ~[spring-boot-2.1.3.RELEASE.jar:2.1.3.RELEASE]
at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:775) ~[spring-boot-2.1.3.RELEASE.jar:2.1.3.RELEASE]
at org.springframework.boot.SpringApplication.refreshContext(SpringApplication.java:397) ~[spring-boot-2.1.3.RELEASE.jar:2.1.3.RELEASE]
at org.springframework.boot.SpringApplication.run(SpringApplication.java:316) ~[spring-boot-2.1.3.RELEASE.jar:2.1.3.RELEASE]
at org.springframework.boot.SpringApplication.run(SpringApplication.java:1260) ~[spring-boot-2.1.3.RELEASE.jar:2.1.3.RELEASE]
at org.springframework.boot.SpringApplication.run(SpringApplication.java:1248) ~[spring-boot-2.1.3.RELEASE.jar:2.1.3.RELEASE]
at me.namila.RESTSpringTest.RestSpringTestApplication.main(RestSpringTestApplication.java:14) ~[main/:na]
Caused by: javax.persistence.PersistenceException: [PersistenceUnit: default] Unable to build Hibernate SessionFactory; nested exception is org.hibernate.exception.JDBCConnectionException: Unable to open JDBC Connection for DDL execution
at org.springframework.orm.jpa.AbstractEntityManagerFactoryBean.buildNativeEntityManagerFactory(AbstractEntityManagerFactoryBean.java:402) ~[spring-orm-5.1.5.RELEASE.jar:5.1.5.RELEASE]
at org.springframework.orm.jpa.AbstractEntityManagerFactoryBean.afterPropertiesSet(AbstractEntityManagerFactoryBean.java:377) ~[spring-orm-5.1.5.RELEASE.jar:5.1.5.RELEASE]
at org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean.afterPropertiesSet(LocalContainerEntityManagerFactoryBean.java:341) ~[spring-orm-5.1.5.RELEASE.jar:5.1.5.RELEASE]
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.invokeInitMethods(AbstractAutowireCapableBeanFactory.java:1821) ~[spring-beans-5.1.5.RELEASE.jar:5.1.5.RELEASE]
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1758) ~[spring-beans-5.1.5.RELEASE.jar:5.1.5.RELEASE]
... 16 common frames omitted
Caused by: org.hibernate.exception.JDBCConnectionException: Unable to open JDBC Connection for DDL execution
at org.hibernate.exception.internal.SQLStateConversionDelegate.convert(SQLStateConversionDelegate.java:115) ~[hibernate-core-5.3.7.Final.jar:5.3.7.Final]
at org.hibernate.exception.internal.StandardSQLExceptionConverter.convert(StandardSQLExceptionConverter.java:42) ~[hibernate-core-5.3.7.Final.jar:5.3.7.Final]
at org.hibernate.engine.jdbc.spi.SqlExceptionHelper.convert(SqlExceptionHelper.java:113) ~[hibernate-core-5.3.7.Final.jar:5.3.7.Final]
at org.hibernate.engine.jdbc.spi.SqlExceptionHelper.convert(SqlExceptionHelper.java:99) ~[hibernate-core-5.3.7.Final.jar:5.3.7.Final]
at org.hibernate.resource.transaction.backend.jdbc.internal.DdlTransactionIsolatorNonJtaImpl.getIsolatedConnection(DdlTransactionIsolatorNonJtaImpl.java:69) ~[hibernate-core-5.3.7.Final.jar:5.3.7.Final]
at org.hibernate.tool.schema.internal.exec.ImprovedExtractionContextImpl.getJdbcConnection(ImprovedExtractionContextImpl.java:60) ~[hibernate-core-5.3.7.Final.jar:5.3.7.Final]
at org.hibernate.tool.schema.internal.exec.ImprovedExtractionContextImpl.getJdbcDatabaseMetaData(ImprovedExtractionContextImpl.java:67) ~[hibernate-core-5.3.7.Final.jar:5.3.7.Final]
at org.hibernate.tool.schema.extract.internal.InformationExtractorJdbcDatabaseMetaDataImpl.getTables(InformationExtractorJdbcDatabaseMetaDataImpl.java:329) ~[hibernate-core-5.3.7.Final.jar:5.3.7.Final]
at org.hibernate.tool.schema.extract.internal.DatabaseInformationImpl.getTablesInformation(DatabaseInformationImpl.java:120) ~[hibernate-core-5.3.7.Final.jar:5.3.7.Final]
at org.hibernate.tool.schema.internal.GroupedSchemaMigratorImpl.performTablesMigration(GroupedSchemaMigratorImpl.java:65) ~[hibernate-core-5.3.7.Final.jar:5.3.7.Final]
at org.hibernate.tool.schema.internal.AbstractSchemaMigrator.performMigration(AbstractSchemaMigrator.java:207) ~[hibernate-core-5.3.7.Final.jar:5.3.7.Final]
at org.hibernate.tool.schema.internal.AbstractSchemaMigrator.doMigration(AbstractSchemaMigrator.java:114) ~[hibernate-core-5.3.7.Final.jar:5.3.7.Final]
at org.hibernate.tool.schema.spi.SchemaManagementToolCoordinator.performDatabaseAction(SchemaManagementToolCoordinator.java:183) ~[hibernate-core-5.3.7.Final.jar:5.3.7.Final]
at org.hibernate.tool.schema.spi.SchemaManagementToolCoordinator.process(SchemaManagementToolCoordinator.java:72) ~[hibernate-core-5.3.7.Final.jar:5.3.7.Final]
at org.hibernate.internal.SessionFactoryImpl.(SessionFactoryImpl.java:310) ~[hibernate-core-5.3.7.Final.jar:5.3.7.Final]
at org.hibernate.boot.internal.SessionFactoryBuilderImpl.build(SessionFactoryBuilderImpl.java:467) ~[hibernate-core-5.3.7.Final.jar:5.3.7.Final]
at org.hibernate.jpa.boot.internal.EntityManagerFactoryBuilderImpl.build(EntityManagerFactoryBuilderImpl.java:939) ~[hibernate-core-5.3.7.Final.jar:5.3.7.Final]
at org.springframework.orm.jpa.vendor.SpringHibernateJpaPersistenceProvider.createContainerEntityManagerFactory(SpringHibernateJpaPersistenceProvider.java:57) ~[spring-orm-5.1.5.RELEASE.jar:5.1.5.RELEASE]
at org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean.createNativeEntityManagerFactory(LocalContainerEntityManagerFactoryBean.java:365) ~[spring-orm-5.1.5.RELEASE.jar:5.1.5.RELEASE]
at org.springframework.orm.jpa.AbstractEntityManagerFactoryBean.buildNativeEntityManagerFactory(AbstractEntityManagerFactoryBean.java:390) ~[spring-orm-5.1.5.RELEASE.jar:5.1.5.RELEASE]
... 20 common frames omitted
Caused by: 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.(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:136) ~[HikariCP-3.2.0.jar:na]
at com.zaxxer.hikari.pool.PoolBase.newConnection(PoolBase.java:369) ~[HikariCP-3.2.0.jar:na]
at com.zaxxer.hikari.pool.PoolBase.newPoolEntry(PoolBase.java:198) ~[HikariCP-3.2.0.jar:na]
at com.zaxxer.hikari.pool.HikariPool.createPoolEntry(HikariPool.java:467) ~[HikariCP-3.2.0.jar:na]
at com.zaxxer.hikari.pool.HikariPool.checkFailFast(HikariPool.java:541) ~[HikariCP-3.2.0.jar:na]
at com.zaxxer.hikari.pool.HikariPool.(HikariPool.java:115) ~[HikariCP-3.2.0.jar:na]
at com.zaxxer.hikari.HikariDataSource.getConnection(HikariDataSource.java:112) ~[HikariCP-3.2.0.jar:na]
at org.hibernate.engine.jdbc.connections.internal.DatasourceConnectionProviderImpl.getConnection(DatasourceConnectionProviderImpl.java:122) ~[hibernate-core-5.3.7.Final.jar:5.3.7.Final]
at org.hibernate.engine.jdbc.env.internal.JdbcEnvironmentInitiator$ConnectionProviderJdbcConnectionAccess.obtainConnection(JdbcEnvironmentInitiator.java:180) ~[hibernate-core-5.3.7.Final.jar:5.3.7.Final]
at org.hibernate.resource.transaction.backend.jdbc.internal.DdlTransactionIsolatorNonJtaImpl.getIsolatedConnection(DdlTransactionIsolatorNonJtaImpl.java:43) ~[hibernate-core-5.3.7.Final.jar:5.3.7.Final]
... 35 common frames omitted
Caused by: com.mysql.cj.exceptions.CJCommunicationsException: 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 java.base/jdk.internal.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method) ~[na:na]
at java.base/jdk.internal.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62) ~[na:na]
at java.base/jdk.internal.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45) ~[na:na]
at java.base/java.lang.reflect.Constructor.newInstance(Constructor.java:490) ~[na:na]
at com.mysql.cj.exceptions.ExceptionFactory.createException(ExceptionFactory.java:61) ~[mysql-connector-java-8.0.15.jar:8.0.15]
at com.mysql.cj.exceptions.ExceptionFactory.createException(ExceptionFactory.java:105) ~[mysql-connector-java-8.0.15.jar:8.0.15]
at com.mysql.cj.exceptions.ExceptionFactory.createException(ExceptionFactory.java:151) ~[mysql-connector-java-8.0.15.jar:8.0.15]
at com.mysql.cj.exceptions.ExceptionFactory.createCommunicationsException(ExceptionFactory.java:167) ~[mysql-connector-java-8.0.15.jar:8.0.15]
at com.mysql.cj.protocol.a.NativeSocketConnection.connect(NativeSocketConnection.java:91) ~[mysql-connector-java-8.0.15.jar:8.0.15]
at com.mysql.cj.NativeSession.connect(NativeSession.java:152) ~[mysql-connector-java-8.0.15.jar:8.0.15]
at com.mysql.cj.jdbc.ConnectionImpl.connectOneTryOnly(ConnectionImpl.java:955) ~[mysql-connector-java-8.0.15.jar:8.0.15]
at com.mysql.cj.jdbc.ConnectionImpl.createNewIO(ConnectionImpl.java:825) ~[mysql-connector-java-8.0.15.jar:8.0.15]
... 48 common frames omitted
Caused by: java.net.ConnectException: Connection refused (Connection refused)
at java.base/java.net.PlainSocketImpl.socketConnect(Native Method) ~[na:na]
at java.base/java.net.AbstractPlainSocketImpl.doConnect(AbstractPlainSocketImpl.java:399) ~[na:na]
at java.base/java.net.AbstractPlainSocketImpl.connectToAddress(AbstractPlainSocketImpl.java:242) ~[na:na]
at java.base/java.net.AbstractPlainSocketImpl.connect(AbstractPlainSocketImpl.java:224) ~[na:na]
at java.base/java.net.SocksSocketImpl.connect(SocksSocketImpl.java:392) ~[na:na]
at java.base/java.net.Socket.connect(Socket.java:609) ~[na:na]
at com.mysql.cj.protocol.StandardSocketFactory.connect(StandardSocketFactory.java:155) ~[mysql-connector-java-8.0.15.jar:8.0.15]
at com.mysql.cj.protocol.a.NativeSocketConnection.connect(NativeSocketConnection.java:65) ~[mysql-connector-java-8.0.15.jar:8.0.15]
... 51 common frames omitted

Task :bootRun FAILED
`

[namila007]

unable to connect to mysql using yur project, can you help with this:

`Caused by: com.mysql.cj.exceptions.CJCommunicationsException: 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 java.base/jdk.internal.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method) ~[na:na]
at java.base/jdk.internal.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62) ~[na:na]
at java.base/jdk.internal.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45) ~[na:na]
at java.base/java.lang.reflect.Constructor.newInstance(Constructor.java:490) ~[na:na]
at com.mysql.cj.exceptions.ExceptionFactory.createException(ExceptionFactory.java:61) ~[mysql-connector-java-8.0.15.jar:8.0.15]
at com.mysql.cj.exceptions.ExceptionFactory.createException(ExceptionFactory.java:105) ~[mysql-connector-java-8.0.15.jar:8.0.15]
at com.mysql.cj.exceptions.ExceptionFactory.createException(ExceptionFactory.java:151) ~[mysql-connector-java-8.0.15.jar:8.0.15]
at com.mysql.cj.exceptions.ExceptionFactory.createCommunicationsException(ExceptionFactory.java:167) ~[mysql-connector-java-8.0.15.jar:8.0.15]
at com.mysql.cj.protocol.a.NativeSocketConnection.connect(NativeSocketConnection.java:91) ~[mysql-connector-java-8.0.15.jar:8.0.15]
at com.mysql.cj.NativeSession.connect(NativeSession.java:152) ~[mysql-connector-java-8.0.15.jar:8.0.15]
at com.mysql.cj.jdbc.ConnectionImpl.connectOneTryOnly(ConnectionImpl.java:955) ~[mysql-connector-java-8.0.15.jar:8.0.15]
at com.mysql.cj.jdbc.ConnectionImpl.createNewIO(ConnectionImpl.java:825) ~[mysql-connector-java-8.0.15.jar:8.0.15]
... 48 common frames omitted
Caused by: java.net.ConnectException: Connection refused (Connection refused)
at java.base/java.net.PlainSocketImpl.socketConnect(Native Method) ~[na:na]
at java.base/java.net.AbstractPlainSocketImpl.doConnect(AbstractPlainSocketImpl.java:399) ~[na:na]
at java.base/java.net.AbstractPlainSocketImpl.connectToAddress(AbstractPlainSocketImpl.java:242) ~[na:na]
at java.base/java.net.AbstractPlainSocketImpl.connect(AbstractPlainSocketImpl.java:224) ~[na:na]
at java.base/java.net.SocksSocketImpl.connect(SocksSocketImpl.java:392) ~[na:na]
at java.base/java.net.Socket.connect(Socket.java:609) ~[na:na]
at com.mysql.cj.protocol.StandardSocketFactory.connect(StandardSocketFactory.java:155) ~[mysql-connector-java-8.0.15.jar:8.0.15]
at com.mysql.cj.protocol.a.NativeSocketConnection.connect(NativeSocketConnection.java:65) ~[mysql-connector-java-8.0.15.jar:8.0.15]
... 51 common frames omitted

2021-08-25 09:42:30.420 WARN 78834 --- [ main] o.h.engine.jdbc.spi.SqlExceptionHelper : SQL Error: 0, SQLState: 08S01
2021-08-25 09:42:30.420 ERROR 78834 --- [ main] o.h.engine.jdbc.spi.SqlExceptionHelper : 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.
2021-08-25 09:42:30.427 WARN 78834 --- [ main] ConfigServletWebServerApplicationContext : Exception encountered during context initialization - cancelling refresh attempt: org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'entityManagerFactory' defined in class path resource [org/springframework/boot/autoconfigure/orm/jpa/HibernateJpaConfiguration.class]: Invocation of init method failed; nested exception is javax.persistence.PersistenceException: [PersistenceUnit: default] Unable to build Hibernate SessionFactory; nested exception is org.hibernate.exception.JDBCConnectionException: Unable to open JDBC Connection for DDL execution
2021-08-25 09:42:30.428 INFO 78834 --- [ main] o.apache.catalina.core.StandardService : Stopping service [Tomcat]
2021-08-25 09:42:30.439 INFO 78834 --- [ main] ConditionEvaluationReportLoggingListener :

Error starting ApplicationContext. To display the conditions report re-run your application with 'debug' enabled.
2021-08-25 09:42:30.442 ERROR 78834 --- [ main] o.s.boot.SpringApplication : Application run failed

org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'entityManagerFactory' defined in class path resource [org/springframework/boot/autoconfigure/orm/jpa/HibernateJpaConfiguration.class]: Invocation of init method failed; nested exception is javax.persistence.PersistenceException: [PersistenceUnit: default] Unable to build Hibernate SessionFactory; nested exception is org.hibernate.exception.JDBCConnectionException: Unable to open JDBC Connection for DDL execution
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1762) ~[spring-beans-5.1.5.RELEASE.jar:5.1.5.RELEASE]
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:593) ~[spring-beans-5.1.5.RELEASE.jar:5.1.5.RELEASE]
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:515) ~[spring-beans-5.1.5.RELEASE.jar:5.1.5.RELEASE]
at org.springframework.beans.factory.support.AbstractBeanFactory.lambda$doGetBean$0(AbstractBeanFactory.java:320) ~[spring-beans-5.1.5.RELEASE.jar:5.1.5.RELEASE]
at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:222) ~[spring-beans-5.1.5.RELEASE.jar:5.1.5.RELEASE]
at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:318) ~[spring-beans-5.1.5.RELEASE.jar:5.1.5.RELEASE]
at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:199) ~[spring-beans-5.1.5.RELEASE.jar:5.1.5.RELEASE]
at org.springframework.context.support.AbstractApplicationContext.getBean(AbstractApplicationContext.java:1105) ~[spring-context-5.1.5.RELEASE.jar:5.1.5.RELEASE]
at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:867) ~[spring-context-5.1.5.RELEASE.jar:5.1.5.RELEASE]
at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:549) ~[spring-context-5.1.5.RELEASE.jar:5.1.5.RELEASE]
at org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.refresh(ServletWebServerApplicationContext.java:142) ~[spring-boot-2.1.3.RELEASE.jar:2.1.3.RELEASE]
at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:775) ~[spring-boot-2.1.3.RELEASE.jar:2.1.3.RELEASE]
at org.springframework.boot.SpringApplication.refreshContext(SpringApplication.java:397) ~[spring-boot-2.1.3.RELEASE.jar:2.1.3.RELEASE]
at org.springframework.boot.SpringApplication.run(SpringApplication.java:316) ~[spring-boot-2.1.3.RELEASE.jar:2.1.3.RELEASE]
at org.springframework.boot.SpringApplication.run(SpringApplication.java:1260) ~[spring-boot-2.1.3.RELEASE.jar:2.1.3.RELEASE]
at org.springframework.boot.SpringApplication.run(SpringApplication.java:1248) ~[spring-boot-2.1.3.RELEASE.jar:2.1.3.RELEASE]
at me.namila.RESTSpringTest.RestSpringTestApplication.main(RestSpringTestApplication.java:14) ~[main/:na]
Caused by: javax.persistence.PersistenceException: [PersistenceUnit: default] Unable to build Hibernate SessionFactory; nested exception is org.hibernate.exception.JDBCConnectionException: Unable to open JDBC Connection for DDL execution
at org.springframework.orm.jpa.AbstractEntityManagerFactoryBean.buildNativeEntityManagerFactory(AbstractEntityManagerFactoryBean.java:402) ~[spring-orm-5.1.5.RELEASE.jar:5.1.5.RELEASE]
at org.springframework.orm.jpa.AbstractEntityManagerFactoryBean.afterPropertiesSet(AbstractEntityManagerFactoryBean.java:377) ~[spring-orm-5.1.5.RELEASE.jar:5.1.5.RELEASE]
at org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean.afterPropertiesSet(LocalContainerEntityManagerFactoryBean.java:341) ~[spring-orm-5.1.5.RELEASE.jar:5.1.5.RELEASE]
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.invokeInitMethods(AbstractAutowireCapableBeanFactory.java:1821) ~[spring-beans-5.1.5.RELEASE.jar:5.1.5.RELEASE]
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1758) ~[spring-beans-5.1.5.RELEASE.jar:5.1.5.RELEASE]
... 16 common frames omitted
Caused by: org.hibernate.exception.JDBCConnectionException: Unable to open JDBC Connection for DDL execution
at org.hibernate.exception.internal.SQLStateConversionDelegate.convert(SQLStateConversionDelegate.java:115) ~[hibernate-core-5.3.7.Final.jar:5.3.7.Final]
at org.hibernate.exception.internal.StandardSQLExceptionConverter.convert(StandardSQLExceptionConverter.java:42) ~[hibernate-core-5.3.7.Final.jar:5.3.7.Final]
at org.hibernate.engine.jdbc.spi.SqlExceptionHelper.convert(SqlExceptionHelper.java:113) ~[hibernate-core-5.3.7.Final.jar:5.3.7.Final]
at org.hibernate.engine.jdbc.spi.SqlExceptionHelper.convert(SqlExceptionHelper.java:99) ~[hibernate-core-5.3.7.Final.jar:5.3.7.Final]
at org.hibernate.resource.transaction.backend.jdbc.internal.DdlTransactionIsolatorNonJtaImpl.getIsolatedConnection(DdlTransactionIsolatorNonJtaImpl.java:69) ~[hibernate-core-5.3.7.Final.jar:5.3.7.Final]
at org.hibernate.tool.schema.internal.exec.ImprovedExtractionContextImpl.getJdbcConnection(ImprovedExtractionContextImpl.java:60) ~[hibernate-core-5.3.7.Final.jar:5.3.7.Final]
at org.hibernate.tool.schema.internal.exec.ImprovedExtractionContextImpl.getJdbcDatabaseMetaData(ImprovedExtractionContextImpl.java:67) ~[hibernate-core-5.3.7.Final.jar:5.3.7.Final]
at org.hibernate.tool.schema.extract.internal.InformationExtractorJdbcDatabaseMetaDataImpl.getTables(InformationExtractorJdbcDatabaseMetaDataImpl.java:329) ~[hibernate-core-5.3.7.Final.jar:5.3.7.Final]
at org.hibernate.tool.schema.extract.internal.DatabaseInformationImpl.getTablesInformation(DatabaseInformationImpl.java:120) ~[hibernate-core-5.3.7.Final.jar:5.3.7.Final]
at org.hibernate.tool.schema.internal.GroupedSchemaMigratorImpl.performTablesMigration(GroupedSchemaMigratorImpl.java:65) ~[hibernate-core-5.3.7.Final.jar:5.3.7.Final]
at org.hibernate.tool.schema.internal.AbstractSchemaMigrator.performMigration(AbstractSchemaMigrator.java:207) ~[hibernate-core-5.3.7.Final.jar:5.3.7.Final]
at org.hibernate.tool.schema.internal.AbstractSchemaMigrator.doMigration(AbstractSchemaMigrator.java:114) ~[hibernate-core-5.3.7.Final.jar:5.3.7.Final]
at org.hibernate.tool.schema.spi.SchemaManagementToolCoordinator.performDatabaseAction(SchemaManagementToolCoordinator.java:183) ~[hibernate-core-5.3.7.Final.jar:5.3.7.Final]
at org.hibernate.tool.schema.spi.SchemaManagementToolCoordinator.process(SchemaManagementToolCoordinator.java:72) ~[hibernate-core-5.3.7.Final.jar:5.3.7.Final]
at org.hibernate.internal.SessionFactoryImpl.(SessionFactoryImpl.java:310) ~[hibernate-core-5.3.7.Final.jar:5.3.7.Final]
at org.hibernate.boot.internal.SessionFactoryBuilderImpl.build(SessionFactoryBuilderImpl.java:467) ~[hibernate-core-5.3.7.Final.jar:5.3.7.Final]
at org.hibernate.jpa.boot.internal.EntityManagerFactoryBuilderImpl.build(EntityManagerFactoryBuilderImpl.java:939) ~[hibernate-core-5.3.7.Final.jar:5.3.7.Final]
at org.springframework.orm.jpa.vendor.SpringHibernateJpaPersistenceProvider.createContainerEntityManagerFactory(SpringHibernateJpaPersistenceProvider.java:57) ~[spring-orm-5.1.5.RELEASE.jar:5.1.5.RELEASE]
at org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean.createNativeEntityManagerFactory(LocalContainerEntityManagerFactoryBean.java:365) ~[spring-orm-5.1.5.RELEASE.jar:5.1.5.RELEASE]
at org.springframework.orm.jpa.AbstractEntityManagerFactoryBean.buildNativeEntityManagerFactory(AbstractEntityManagerFactoryBean.java:390) ~[spring-orm-5.1.5.RELEASE.jar:5.1.5.RELEASE]
... 20 common frames omitted
Caused by: 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.(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:136) ~[HikariCP-3.2.0.jar:na]
at com.zaxxer.hikari.pool.PoolBase.newConnection(PoolBase.java:369) ~[HikariCP-3.2.0.jar:na]
at com.zaxxer.hikari.pool.PoolBase.newPoolEntry(PoolBase.java:198) ~[HikariCP-3.2.0.jar:na]
at com.zaxxer.hikari.pool.HikariPool.createPoolEntry(HikariPool.java:467) ~[HikariCP-3.2.0.jar:na]
at com.zaxxer.hikari.pool.HikariPool.checkFailFast(HikariPool.java:541) ~[HikariCP-3.2.0.jar:na]
at com.zaxxer.hikari.pool.HikariPool.(HikariPool.java:115) ~[HikariCP-3.2.0.jar:na]
at com.zaxxer.hikari.HikariDataSource.getConnection(HikariDataSource.java:112) ~[HikariCP-3.2.0.jar:na]
at org.hibernate.engine.jdbc.connections.internal.DatasourceConnectionProviderImpl.getConnection(DatasourceConnectionProviderImpl.java:122) ~[hibernate-core-5.3.7.Final.jar:5.3.7.Final]
at org.hibernate.engine.jdbc.env.internal.JdbcEnvironmentInitiator$ConnectionProviderJdbcConnectionAccess.obtainConnection(JdbcEnvironmentInitiator.java:180) ~[hibernate-core-5.3.7.Final.jar:5.3.7.Final]
at org.hibernate.resource.transaction.backend.jdbc.internal.DdlTransactionIsolatorNonJtaImpl.getIsolatedConnection(DdlTransactionIsolatorNonJtaImpl.java:43) ~[hibernate-core-5.3.7.Final.jar:5.3.7.Final]
... 35 common frames omitted
Caused by: com.mysql.cj.exceptions.CJCommunicationsException: 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 java.base/jdk.internal.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method) ~[na:na]
at java.base/jdk.internal.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62) ~[na:na]
at java.base/jdk.internal.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45) ~[na:na]
at java.base/java.lang.reflect.Constructor.newInstance(Constructor.java:490) ~[na:na]
at com.mysql.cj.exceptions.ExceptionFactory.createException(ExceptionFactory.java:61) ~[mysql-connector-java-8.0.15.jar:8.0.15]
at com.mysql.cj.exceptions.ExceptionFactory.createException(ExceptionFactory.java:105) ~[mysql-connector-java-8.0.15.jar:8.0.15]
at com.mysql.cj.exceptions.ExceptionFactory.createException(ExceptionFactory.java:151) ~[mysql-connector-java-8.0.15.jar:8.0.15]
at com.mysql.cj.exceptions.ExceptionFactory.createCommunicationsException(ExceptionFactory.java:167) ~[mysql-connector-java-8.0.15.jar:8.0.15]
at com.mysql.cj.protocol.a.NativeSocketConnection.connect(NativeSocketConnection.java:91) ~[mysql-connector-java-8.0.15.jar:8.0.15]
at com.mysql.cj.NativeSession.connect(NativeSession.java:152) ~[mysql-connector-java-8.0.15.jar:8.0.15]
at com.mysql.cj.jdbc.ConnectionImpl.connectOneTryOnly(ConnectionImpl.java:955) ~[mysql-connector-java-8.0.15.jar:8.0.15]
at com.mysql.cj.jdbc.ConnectionImpl.createNewIO(ConnectionImpl.java:825) ~[mysql-connector-java-8.0.15.jar:8.0.15]
... 48 common frames omitted
Caused by: java.net.ConnectException: Connection refused (Connection refused)
at java.base/java.net.PlainSocketImpl.socketConnect(Native Method) ~[na:na]
at java.base/java.net.AbstractPlainSocketImpl.doConnect(AbstractPlainSocketImpl.java:399) ~[na:na]
at java.base/java.net.AbstractPlainSocketImpl.connectToAddress(AbstractPlainSocketImpl.java:242) ~[na:na]
at java.base/java.net.AbstractPlainSocketImpl.connect(AbstractPlainSocketImpl.java:224) ~[na:na]
at java.base/java.net.SocksSocketImpl.connect(SocksSocketImpl.java:392) ~[na:na]
at java.base/java.net.Socket.connect(Socket.java:609) ~[na:na]
at com.mysql.cj.protocol.StandardSocketFactory.connect(StandardSocketFactory.java:155) ~[mysql-connector-java-8.0.15.jar:8.0.15]
at com.mysql.cj.protocol.a.NativeSocketConnection.connect(NativeSocketConnection.java:65) ~[mysql-connector-java-8.0.15.jar:8.0.15]
... 51 common frames omitted

Task :bootRun FAILED
`

have you checked your mysql url ? jdbc:mysql://localhost:3306/restspring
change the port according to your mysql server and create a db called "restspring" or change it according to ur db name