springboot项目启动报错Communications link failure

• 2020 年 11 月 24 日
• 笔记
• MySQL, springboot

环境情况，MySQL版本如下：

报错情况如下（看上去是和数据库有关）：

com.mysql.jdbc.exceptions.jdbc4.CommunicationsException: Communications link failure

The last packet successfully received from the server was 59 milliseconds ago.  The last packet sent successfully to the server was 59 milliseconds ago.
    at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method) ~[na:1.8.0_275]
    at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62) ~[na:1.8.0_275]
    at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45) ~[na:1.8.0_275]
    at java.lang.reflect.Constructor.newInstance(Constructor.java:423) ~[na:1.8.0_275]
    at com.mysql.jdbc.Util.handleNewInstance(Util.java:425) ~[mysql-connector-java-5.1.47.jar:5.1.47]
    at com.mysql.jdbc.SQLError.createCommunicationsException(SQLError.java:990) ~[mysql-connector-java-5.1.47.jar:5.1.47]
    at com.mysql.jdbc.ExportControlled.transformSocketToSSLSocket(ExportControlled.java:201) ~[mysql-connector-java-5.1.47.jar:5.1.47]
    at com.mysql.jdbc.MysqlIO.negotiateSSLConnection(MysqlIO.java:4914) ~[mysql-connector-java-5.1.47.jar:5.1.47]
    at com.mysql.jdbc.MysqlIO.proceedHandshakeWithPluggableAuthentication(MysqlIO.java:1663) ~[mysql-connector-java-5.1.47.jar:5.1.47]
    at com.mysql.jdbc.MysqlIO.doHandshake(MysqlIO.java:1224) ~[mysql-connector-java-5.1.47.jar:5.1.47]
    at com.mysql.jdbc.ConnectionImpl.coreConnect(ConnectionImpl.java:2199) ~[mysql-connector-java-5.1.47.jar:5.1.47]
    at com.mysql.jdbc.ConnectionImpl.connectOneTryOnly(ConnectionImpl.java:2230) ~[mysql-connector-java-5.1.47.jar:5.1.47]
    at com.mysql.jdbc.ConnectionImpl.createNewIO(ConnectionImpl.java:2025) ~[mysql-connector-java-5.1.47.jar:5.1.47]
    at com.mysql.jdbc.ConnectionImpl.<init>(ConnectionImpl.java:778) ~[mysql-connector-java-5.1.47.jar:5.1.47]
    at com.mysql.jdbc.JDBC4Connection.<init>(JDBC4Connection.java:47) ~[mysql-connector-java-5.1.47.jar:5.1.47]
    at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method) ~[na:1.8.0_275]
    at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62) ~[na:1.8.0_275]
    at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45) ~[na:1.8.0_275]
    at java.lang.reflect.Constructor.newInstance(Constructor.java:423) ~[na:1.8.0_275]
    at com.mysql.jdbc.Util.handleNewInstance(Util.java:425) ~[mysql-connector-java-5.1.47.jar:5.1.47]
    at com.mysql.jdbc.ConnectionImpl.getInstance(ConnectionImpl.java:386) ~[mysql-connector-java-5.1.47.jar:5.1.47]
    at com.mysql.jdbc.NonRegisteringDriver.connect(NonRegisteringDriver.java:330) ~[mysql-connector-java-5.1.47.jar:5.1.47]
    at com.alibaba.druid.filter.FilterChainImpl.connection_connect(FilterChainImpl.java:156) ~[druid-1.2.3.jar:1.2.3]
    at com.alibaba.druid.filter.FilterAdapter.connection_connect(FilterAdapter.java:787) ~[druid-1.2.3.jar:1.2.3]
    at com.alibaba.druid.filter.FilterEventAdapter.connection_connect(FilterEventAdapter.java:38) ~[druid-1.2.3.jar:1.2.3]
    at com.alibaba.druid.filter.FilterChainImpl.connection_connect(FilterChainImpl.java:150) ~[druid-1.2.3.jar:1.2.3]
    at com.alibaba.druid.filter.FilterAdapter.connection_connect(FilterAdapter.java:787) ~[druid-1.2.3.jar:1.2.3]
    at com.alibaba.druid.filter.FilterChainImpl.connection_connect(FilterChainImpl.java:150) ~[druid-1.2.3.jar:1.2.3]
    at com.alibaba.druid.filter.stat.StatFilter.connection_connect(StatFilter.java:227) ~[druid-1.2.3.jar:1.2.3]
    at com.alibaba.druid.filter.FilterChainImpl.connection_connect(FilterChainImpl.java:150) ~[druid-1.2.3.jar:1.2.3]
    at com.alibaba.druid.pool.DruidAbstractDataSource.createPhysicalConnection(DruidAbstractDataSource.java:1654) ~[druid-1.2.3.jar:1.2.3]
    at com.alibaba.druid.pool.DruidAbstractDataSource.createPhysicalConnection(DruidAbstractDataSource.java:1718) ~[druid-1.2.3.jar:1.2.3]
    at com.alibaba.druid.pool.DruidDataSource$CreateConnectionThread.run(DruidDataSource.java:2785) ~[druid-1.2.3.jar:1.2.3]
Caused by: javax.net.ssl.SSLHandshakeException: Received fatal alert: protocol_version
    at sun.security.ssl.Alert.createSSLException(Alert.java:131) ~[na:1.8.0_275]
    at sun.security.ssl.Alert.createSSLException(Alert.java:117) ~[na:1.8.0_275]
    at sun.security.ssl.TransportContext.fatal(TransportContext.java:311) ~[na:1.8.0_275]
    at sun.security.ssl.Alert$AlertConsumer.consume(Alert.java:293) ~[na:1.8.0_275]
    at sun.security.ssl.TransportContext.dispatch(TransportContext.java:185) ~[na:1.8.0_275]
    at sun.security.ssl.SSLTransport.decode(SSLTransport.java:149) ~[na:1.8.0_275]
    at sun.security.ssl.SSLSocketImpl.decode(SSLSocketImpl.java:1143) ~[na:1.8.0_275]
    at sun.security.ssl.SSLSocketImpl.readHandshakeRecord(SSLSocketImpl.java:1054) ~[na:1.8.0_275]
    at sun.security.ssl.SSLSocketImpl.startHandshake(SSLSocketImpl.java:394) ~[na:1.8.0_275]
    at com.mysql.jdbc.ExportControlled.transformSocketToSSLSocket(ExportControlled.java:186) ~[mysql-connector-java-5.1.47.jar:5.1.47]
    ... 26 common frames omitted

网上查找了很多方法都没有效果，应该是与我的问题无关，我仔细观察最后的真正的错误原因

Caused by: javax.net.ssl.SSLHandshakeException: Received fatal alert: protocol_version

于是我猜想是MySQL驱动的问题，于是我将驱动依赖改为了如下

<!--数据库-->
<dependency>
  <groupId>mysql</groupId>
  <artifactId>mysql-connector-java</artifactId>
  <version>5.1.49</version>
</dependency>

原先的是5.1.47报错了，改成上面的5.1.49版本就可以了正常启动springboot的项目了