MySql無法連線資料庫

我的LOG如下：

2018-03-29 13:56:57.023 ERROR 5084 --- [           main] 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 successfully received from the server was 12 milliseconds ago.  The last packet sent successfully to the server was 11 milliseconds ago.
	at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method) ~[na:1.8.0_121]
	at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62) ~[na:1.8.0_121]
	at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45) ~[na:1.8.0_121]
	at java.lang.reflect.Constructor.newInstance(Constructor.java:423) ~[na:1.8.0_121]
	at com.mysql.jdbc.Util.handleNewInstance(Util.java:425) ~[mysql-connector-java-5.1.45.jar:5.1.45]
	at com.mysql.jdbc.SQLError.createCommunicationsException(SQLError.java:990) ~[mysql-connector-java-5.1.45.jar:5.1.45]
	at com.mysql.jdbc.ExportControlled.transformSocketToSSLSocket(ExportControlled.java:203) ~[mysql-connector-java-5.1.45.jar:5.1.45]
	at com.mysql.jdbc.MysqlIO.negotiateSSLConnection(MysqlIO.java:4901) ~[mysql-connector-java-5.1.45.jar:5.1.45]
	at com.mysql.jdbc.MysqlIO.proceedHandshakeWithPluggableAuthentication(MysqlIO.java:1659) ~[mysql-connector-java-5.1.45.jar:5.1.45]
	at com.mysql.jdbc.MysqlIO.doHandshake(MysqlIO.java:1226) ~[mysql-connector-java-5.1.45.jar:5.1.45]
	at com.mysql.jdbc.ConnectionImpl.coreConnect(ConnectionImpl.java:2188) ~[mysql-connector-java-5.1.45.jar:5.1.45]
	at com.mysql.jdbc.ConnectionImpl.connectOneTryOnly(ConnectionImpl.java:2219) ~[mysql-connector-java-5.1.45.jar:5.1.45]
	at com.mysql.jdbc.ConnectionImpl.createNewIO(ConnectionImpl.java:2014) ~[mysql-connector-java-5.1.45.jar:5.1.45]
	at com.mysql.jdbc.ConnectionImpl.<init>(ConnectionImpl.java:776) ~[mysql-connector-java-5.1.45.jar:5.1.45]
	at com.mysql.jdbc.JDBC4Connection.<init>(JDBC4Connection.java:47) ~[mysql-connector-java-5.1.45.jar:5.1.45]
	at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method) ~[na:1.8.0_121]
	at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62) ~[na:1.8.0_121]
	at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45) ~[na:1.8.0_121]
	at java.lang.reflect.Constructor.newInstance(Constructor.java:423) ~[na:1.8.0_121]
	at com.mysql.jdbc.Util.handleNewInstance(Util.java:425) ~[mysql-connector-java-5.1.45.jar:5.1.45]
	at com.mysql.jdbc.ConnectionImpl.getInstance(ConnectionImpl.java:386) ~[mysql-connector-java-5.1.45.jar:5.1.45]
	at com.mysql.jdbc.NonRegisteringDriver.connect(NonRegisteringDriver.java:330) ~[mysql-connector-java-5.1.45.jar:5.1.45]
	at org.apache.tomcat.jdbc.pool.PooledConnection.connectUsingDriver(PooledConnection.java:310) ~[tomcat-jdbc-8.5.27.jar:na]
	at org.apache.tomcat.jdbc.pool.PooledConnection.connect(PooledConnection.java:203) ~[tomcat-jdbc-8.5.27.jar:na]
	at org.apache.tomcat.jdbc.pool.ConnectionPool.createConnection(ConnectionPool.java:735) [tomcat-jdbc-8.5.27.jar:na]
	at org.apache.tomcat.jdbc.pool.ConnectionPool.borrowConnection(ConnectionPool.java:667) [tomcat-jdbc-8.5.27.jar:na]
	at org.apache.tomcat.jdbc.pool.ConnectionPool.init(ConnectionPool.java:482) [tomcat-jdbc-8.5.27.jar:na]
	at org.apache.tomcat.jdbc.pool.ConnectionPool.<init>(ConnectionPool.java:154) [tomcat-jdbc-8.5.27.jar:na]
	at org.apache.tomcat.jdbc.pool.DataSourceProxy.pCreatePool(DataSourceProxy.java:118) [tomcat-jdbc-8.5.27.jar:na]
	at org.apache.tomcat.jdbc.pool.DataSourceProxy.createPool(DataSourceProxy.java:107) [tomcat-jdbc-8.5.27.jar:na]
	at org.apache.tomcat.jdbc.pool.DataSourceProxy.getConnection(DataSourceProxy.java:131) [tomcat-jdbc-8.5.27.jar:na]
	at org.hibernate.engine.jdbc.connections.internal.DatasourceConnectionProviderImpl.getConnection(DatasourceConnectionProviderImpl.java:122) [hibernate-core-5.0.12.Final.jar:5.0.12.Final]
	at org.hibernate.engine.jdbc.env.internal.JdbcEnvironmentInitiator$ConnectionProviderJdbcConnectionAccess.obtainConnection(JdbcEnvironmentInitiator.java:180) [hibernate-core-5.0.12.Final.jar:5.0.12.Final]
	at org.hibernate.engine.jdbc.env.internal.JdbcEnvironmentInitiator.initiateService(JdbcEnvironmentInitiator.java:68) [hibernate-core-5.0.12.Final.jar:5.0.12.Final]
	at org.hibernate.engine.jdbc.env.internal.JdbcEnvironmentInitiator.initiateService(JdbcEnvironmentInitiator.java:35) [hibernate-core-5.0.12.Final.jar:5.0.12.Final]
	at org.hibernate.boot.registry.internal.StandardServiceRegistryImpl.initiateService(StandardServiceRegistryImpl.java:88) [hibernate-core-5.0.12.Final.jar:5.0.12.Final]
	at org.hibernate.service.internal.AbstractServiceRegistryImpl.createService(AbstractServiceRegistryImpl.java:254) [hibernate-core-5.0.12.Final.jar:5.0.12.Final]
	at org.hibernate.service.internal.AbstractServiceRegistryImpl.initializeService(AbstractServiceRegistryImpl.java:228) [hibernate-core-5.0.12.Final.jar:5.0.12.Final]
	at org.hibernate.service.internal.AbstractServiceRegistryImpl.getService(AbstractServiceRegistryImpl.java:207) [hibernate-core-5.0.12.Final.jar:5.0.12.Final]
	at org.hibernate.engine.jdbc.internal.JdbcServicesImpl.configure(JdbcServicesImpl.java:51) [hibernate-core-5.0.12.Final.jar:5.0.12.Final]
	at org.hibernate.boot.registry.internal.StandardServiceRegistryImpl.configureService(StandardServiceRegistryImpl.java:94) [hibernate-core-5.0.12.Final.jar:5.0.12.Final]
	at org.hibernate.service.internal.AbstractServiceRegistryImpl.initializeService(AbstractServiceRegistryImpl.java:237) [hibernate-core-5.0.12.Final.jar:5.0.12.Final]
	at org.hibernate.service.internal.AbstractServiceRegistryImpl.getService(AbstractServiceRegistryImpl.java:207) [hibernate-core-5.0.12.Final.jar:5.0.12.Final]
	at org.hibernate.boot.model.process.spi.MetadataBuildingProcess.handleTypes(MetadataBuildingProcess.java:352) [hibernate-core-5.0.12.Final.jar:5.0.12.Final]
	at org.hibernate.boot.model.process.spi.MetadataBuildingProcess.complete(MetadataBuildingProcess.java:111) [hibernate-core-5.0.12.Final.jar:5.0.12.Final]
	at org.hibernate.jpa.boot.internal.EntityManagerFactoryBuilderImpl.metadata(EntityManagerFactoryBuilderImpl.java:847) [hibernate-entitymanager-5.0.12.Final.jar:5.0.12.Final]
	at org.hibernate.jpa.boot.internal.EntityManagerFactoryBuilderImpl.build(EntityManagerFactoryBuilderImpl.java:874) [hibernate-entitymanager-5.0.12.Final.jar:5.0.12.Final]
	at org.springframework.orm.jpa.vendor.SpringHibernateJpaPersistenceProvider.createContainerEntityManagerFactory(SpringHibernateJpaPersistenceProvider.java:60) [spring-orm-4.3.14.RELEASE.jar:4.3.14.RELEASE]
	at org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean.createNativeEntityManagerFactory(LocalContainerEntityManagerFactoryBean.java:360) [spring-orm-4.3.14.RELEASE.jar:4.3.14.RELEASE]
	at org.springframework.orm.jpa.AbstractEntityManagerFactoryBean.buildNativeEntityManagerFactory(AbstractEntityManagerFactoryBean.java:382) [spring-orm-4.3.14.RELEASE.jar:4.3.14.RELEASE]
	at org.springframework.orm.jpa.AbstractEntityManagerFactoryBean.afterPropertiesSet(AbstractEntityManagerFactoryBean.java:371) [spring-orm-4.3.14.RELEASE.jar:4.3.14.RELEASE]
	at org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean.afterPropertiesSet(LocalContainerEntityManagerFactoryBean.java:336) [spring-orm-4.3.14.RELEASE.jar:4.3.14.RELEASE]
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.invokeInitMethods(AbstractAutowireCapableBeanFactory.java:1687) [spring-beans-4.3.14.RELEASE.jar:4.3.14.RELEASE]
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1624) [spring-beans-4.3.14.RELEASE.jar:4.3.14.RELEASE]
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:555) [spring-beans-4.3.14.RELEASE.jar:4.3.14.RELEASE]
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:483) [spring-beans-4.3.14.RELEASE.jar:4.3.14.RELEASE]
	at org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:306) [spring-beans-4.3.14.RELEASE.jar:4.3.14.RELEASE]
	at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:230) [spring-beans-4.3.14.RELEASE.jar:4.3.14.RELEASE]
	at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:302) [spring-beans-4.3.14.RELEASE.jar:4.3.14.RELEASE]
	at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:197) [spring-beans-4.3.14.RELEASE.jar:4.3.14.RELEASE]
	at org.springframework.context.support.AbstractApplicationContext.getBean(AbstractApplicationContext.java:1080) [spring-context-4.3.14.RELEASE.jar:4.3.14.RELEASE]
	at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:857) [spring-context-4.3.14.RELEASE.jar:4.3.14.RELEASE]
	at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:543) [spring-context-4.3.14.RELEASE.jar:4.3.14.RELEASE]
	at org.springframework.boot.context.embedded.EmbeddedWebApplicationContext.refresh(EmbeddedWebApplicationContext.java:122) [spring-boot-1.5.10.RELEASE.jar:1.5.10.RELEASE]
	at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:693) [spring-boot-1.5.10.RELEASE.jar:1.5.10.RELEASE]
	at org.springframework.boot.SpringApplication.refreshContext(SpringApplication.java:360) [spring-boot-1.5.10.RELEASE.jar:1.5.10.RELEASE]
	at org.springframework.boot.SpringApplication.run(SpringApplication.java:303) [spring-boot-1.5.10.RELEASE.jar:1.5.10.RELEASE]
	at org.springframework.boot.SpringApplication.run(SpringApplication.java:1118) [spring-boot-1.5.10.RELEASE.jar:1.5.10.RELEASE]
	at org.springframework.boot.SpringApplication.run(SpringApplication.java:1107) [spring-boot-1.5.10.RELEASE.jar:1.5.10.RELEASE]
	at com.ilink.mes.Application.main(Application.java:9) [classes/:na]
Caused by: javax.net.ssl.SSLHandshakeException: java.security.cert.CertificateException: java.security.cert.CertPathValidatorException: Path does not chain with any of the trust anchors
	at sun.security.ssl.Alerts.getSSLException(Alerts.java:192) ~[na:1.8.0_121]
	at sun.security.ssl.SSLSocketImpl.fatal(SSLSocketImpl.java:1949) ~[na:1.8.0_121]
	at sun.security.ssl.Handshaker.fatalSE(Handshaker.java:302) ~[na:1.8.0_121]
	at sun.security.ssl.Handshaker.fatalSE(Handshaker.java:296) ~[na:1.8.0_121]
	at sun.security.ssl.ClientHandshaker.serverCertificate(ClientHandshaker.java:1514) ~[na:1.8.0_121]
	at sun.security.ssl.ClientHandshaker.processMessage(ClientHandshaker.java:216) ~[na:1.8.0_121]
	at sun.security.ssl.Handshaker.processLoop(Handshaker.java:1026) ~[na:1.8.0_121]
	at sun.security.ssl.Handshaker.process_record(Handshaker.java:961) ~[na:1.8.0_121]
	at sun.security.ssl.SSLSocketImpl.readRecord(SSLSocketImpl.java:1062) ~[na:1.8.0_121]
	at sun.security.ssl.SSLSocketImpl.performInitialHandshake(SSLSocketImpl.java:1375) ~[na:1.8.0_121]
	at sun.security.ssl.SSLSocketImpl.startHandshake(SSLSocketImpl.java:1403) ~[na:1.8.0_121]
	at sun.security.ssl.SSLSocketImpl.startHandshake(SSLSocketImpl.java:1387) ~[na:1.8.0_121]
	at com.mysql.jdbc.ExportControlled.transformSocketToSSLSocket(ExportControlled.java:188) ~[mysql-connector-java-5.1.45.jar:5.1.45]
	... 63 common frames omitted
Caused by: java.security.cert.CertificateException: java.security.cert.CertPathValidatorException: Path does not chain with any of the trust anchors
	at com.mysql.jdbc.ExportControlled$X509TrustManagerWrapper.checkServerTrusted(ExportControlled.java:304) ~[mysql-connector-java-5.1.45.jar:5.1.45]
	at sun.security.ssl.AbstractTrustManagerWrapper.checkServerTrusted(SSLContextImpl.java:984) ~[na:1.8.0_121]
	at sun.security.ssl.ClientHandshaker.serverCertificate(ClientHandshaker.java:1496) ~[na:1.8.0_121]
	... 71 common frames omitted
Caused by: java.security.cert.CertPathValidatorException: Path does not chain with any of the trust anchors
	at sun.security.provider.certpath.PKIXCertPathValidator.validate(PKIXCertPathValidator.java:153) ~[na:1.8.0_121]
	at sun.security.provider.certpath.PKIXCertPathValidator.engineValidate(PKIXCertPathValidator.java:79) ~[na:1.8.0_121]
	at java.security.cert.CertPathValidator.validate(CertPathValidator.java:292) ~[na:1.8.0_121]
	at com.mysql.jdbc.ExportControlled$X509TrustManagerWrapper.checkServerTrusted(ExportControlled.java:297) ~[mysql-connector-java-5.1.45.jar:5.1.45]
	... 73 common frames omitted
 

我的環境是：

<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-data-jpa</artifactId>
</dependency>

我的MySql伺服器是在CentOS7，版本是：Server version: 5.7.20 MySQL Community Server (GPL)

我的application.properties如下：

spring.datasource.url=jdbc:mysql://192.168.55.130:3306/mes?characterEncoding=utf8&useSSL=true&autoReconnect=false&rewriteBatchedStatements=true
 

解決辦法：

將useSSL=true改為useSSL=false

只能說明伺服器沒有開啟SSL功能。