一、啟動SpringBoot專案報錯

1、連線資料庫報錯

報錯資訊如下：

2022-04-20 19:41:36.756 ERROR 27153 --- [Druid-ConnectionPool-Create-816798571] com.alibaba.druid.pool.DruidDataSource   : create connection SQLException, url: jdbc:mysql://localhost:3306/fmmall2?useSSL=true&useUnicode=true&characterEncoding=utf-8, errorCode 0, state 08S01

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

The last packet successfully received from the server was 8 milliseconds ago.  The last packet sent successfully to the server was 8 milliseconds ago.
    at sun.reflect.GeneratedConstructorAccessor62.newInstance(Unknown Source) ~[na:na]
    at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45) ~[na:1.8.0_144]
    at java.lang.reflect.Constructor.newInstance(Constructor.java:423) ~[na:1.8.0_144]
    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.GeneratedConstructorAccessor55.newInstance(Unknown Source) ~[na:na]
    at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45) ~[na:1.8.0_144]
    at java.lang.reflect.Constructor.newInstance(Constructor.java:423) ~[na:1.8.0_144]
    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.pool.DruidAbstractDataSource.createPhysicalConnection(DruidAbstractDataSource.java:1644) ~[druid-1.1.22.jar!/:1.1.22]
    at com.alibaba.druid.pool.DruidAbstractDataSource.createPhysicalConnection(DruidAbstractDataSource.java:1710) ~[druid-1.1.22.jar!/:1.1.22]
    at com.alibaba.druid.pool.DruidDataSource$CreateConnectionThread.run(DruidDataSource.java:2779) ~[druid-1.1.22.jar!/:1.1.22]
Caused by: javax.net.ssl.SSLHandshakeException: java.security.cert.CertificateException: java.security.cert.CertPathValidatorException: Path does not chain with any of the trust anchors
    at sun.security.ssl.Alerts.getSSLException(Alerts.java:192) ~[na:1.8.0_144]
    at sun.security.ssl.SSLSocketImpl.fatal(SSLSocketImpl.java:1959) ~[na:1.8.0_144]
    at sun.security.ssl.Handshaker.fatalSE(Handshaker.java:302) ~[na:1.8.0_144]
    at sun.security.ssl.Handshaker.fatalSE(Handshaker.java:296) ~[na:1.8.0_144]
    at sun.security.ssl.ClientHandshaker.serverCertificate(ClientHandshaker.java:1514) ~[na:1.8.0_144]
    at sun.security.ssl.ClientHandshaker.processMessage(ClientHandshaker.java:216) ~[na:1.8.0_144]
    at sun.security.ssl.Handshaker.processLoop(Handshaker.java:1026) ~[na:1.8.0_144]
    at sun.security.ssl.Handshaker.process_record(Handshaker.java:961) ~[na:1.8.0_144]
    at sun.security.ssl.SSLSocketImpl.readRecord(SSLSocketImpl.java:1072) ~[na:1.8.0_144]
    at sun.security.ssl.SSLSocketImpl.performInitialHandshake(SSLSocketImpl.java:1385) ~[na:1.8.0_144]
    at sun.security.ssl.SSLSocketImpl.startHandshake(SSLSocketImpl.java:1413) ~[na:1.8.0_144]
    at sun.security.ssl.SSLSocketImpl.startHandshake(SSLSocketImpl.java:1397) ~[na:1.8.0_144]
    at com.mysql.jdbc.ExportControlled.transformSocketToSSLSocket(ExportControlled.java:186) ~[mysql-connector-java-5.1.47.jar!/:5.1.47]
    ... 17 common frames omitted
Caused by: java.security.cert.CertificateException: java.security.cert.CertPathValidatorException: Path does not chain with any of the trust anchors
    at com.mysql.jdbc.ExportControlled$X509TrustManagerWrapper.checkServerTrusted(ExportControlled.java:302) ~[mysql-connector-java-5.1.47.jar!/:5.1.47]
    at sun.security.ssl.AbstractTrustManagerWrapper.checkServerTrusted(SSLContextImpl.java:985) ~[na:1.8.0_144]
    at sun.security.ssl.ClientHandshaker.serverCertificate(ClientHandshaker.java:1496) ~[na:1.8.0_144]
    ... 25 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_144]
    at sun.security.provider.certpath.PKIXCertPathValidator.engineValidate(PKIXCertPathValidator.java:79) ~[na:1.8.0_144]
    at java.security.cert.CertPathValidator.validate(CertPathValidator.java:292) ~[na:1.8.0_144]
    at com.mysql.jdbc.ExportControlled$X509TrustManagerWrapper.checkServerTrusted(ExportControlled.java:295) ~[mysql-connector-java-5.1.47.jar!/:5.1.47]
    ... 27 common frames omitted

報錯原因：linux中連線資料庫不需要用SSL，直接設定為false即可

2、連線郵箱報錯——Spring Boot 傳送郵件時，出現 Mail server connection failed 異常問題

解決方法：檢視相關資料，發現在騰訊雲伺服器上，預設禁用了 25 埠，所以通過25埠去連線郵件伺服器時，就無法連線會報超時錯誤。官方建議使用 465 埠，而 456 埠是 SSL 協議的，所以不僅要換埠，還需要進行 SSL 協議替換。如下為application.yml中進行郵件傳送配置：

spring:
  mail:
    port: 465
    host: smtp.163.com
    username: 
 
18827512193@163.com
    password: NSGOUGXTPJJWPYXB
    default-encoding: utf-8
    protocol: smtp
    properties:
      mail:
        smtp:
          auth: true
          starttls:
           enable: true
           required: true
          ssl:
            enable: true
            socketFactory:
              port: 
 
465
              class: javax.net.ssl.SSLSocketFactory