版权声明：MZ21G https://blog.csdn.net/qq_35793285/article/details/82887656
一、出错信息
Loading class `com.mysql.jdbc.Driver'. This is deprecated. The new driver class is `com.mysql.cj.jdbc.Driver'. The driver is automatically registered via the SPI and manual loading of the driver class is generally unnecessary.原因：
加载数据库驱动类改为如下图：
二、出错信息
Fri Sep 28 17:39:56 CST 2018 WARN: Establishing SSL connection without server's identity verification is not recommended. According to MySQL 5.5.45+, 5.6.26+ and 5.7.6+ requirements SSL connection must be established by default if explicit option isn't set. For compliance with existing applications not using SSL the verifyServerCertificate property is set to 'false'. You need either to explicitly disable SSL by setting useSSL=false, or set useSSL=true and provide truststore for server certificate verification.
java.sql.SQLException: The server time zone value '???ú±ê×??±??' is unrecognized or represents more than one time zone. You must configure either the server or JDBC driver (via the serverTimezone configuration property) to use a more specifc time zone value if you want to utilize time zone support.
at com.mysql.cj.jdbc.exceptions.SQLError.createSQLException(SQLError.java:129)
at com.mysql.cj.jdbc.exceptions.SQLError.createSQLException(SQLError.java:97)
at com.mysql.cj.jdbc.exceptions.SQLError.createSQLException(SQLError.java:89)
at com.mysql.cj.jdbc.exceptions.SQLError.createSQLException(SQLError.java:63)
at com.mysql.cj.jdbc.exceptions.SQLError.createSQLException(SQLError.java:73)
at com.mysql.cj.jdbc.exceptions.SQLExceptionsMapping.translateException(SQLExceptionsMapping.java:76)
at com.mysql.cj.jdbc.ConnectionImpl.createNewIO(ConnectionImpl.java:832)
at com.mysql.cj.jdbc.ConnectionImpl.<init>(ConnectionImpl.java:456)
at com.mysql.cj.jdbc.ConnectionImpl.getInstance(ConnectionImpl.java:240)
at com.mysql.cj.jdbc.NonRegisteringDriver.connect(NonRegisteringDriver.java:207)
at java.sql.DriverManager.getConnection(Unknown Source)
at java.sql.DriverManager.getConnection(Unknown Source)
at 数据库操作.Conn.getConnection(Conn.java:16)
at 数据库操作.Conn.main(Conn.java:27)
Caused by: com.mysql.cj.exceptions.InvalidConnectionAttributeException: The server time zone value '???ú±ê×??±??' is unrecognized or represents more than one time zone. You must configure either the server or JDBC driver (via the serverTimezone configuration property) to use a more specifc time zone value if you want to utilize time zone support.
at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
at sun.reflect.NativeConstructorAccessorImpl.newInstance(Unknown Source)
at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(Unknown Source)
at java.lang.reflect.Constructor.newInstance(Unknown Source)
at com.mysql.cj.exceptions.ExceptionFactory.createException(ExceptionFactory.java:61)
at com.mysql.cj.exceptions.ExceptionFactory.createException(ExceptionFactory.java:85)
at com.mysql.cj.util.TimeUtil.getCanonicalTimezone(TimeUtil.java:128)
at com.mysql.cj.protocol.a.NativeProtocol.configureTimezone(NativeProtocol.java:2236)
at com.mysql.cj.protocol.a.NativeProtocol.initServerSession(NativeProtocol.java:2260)
at com.mysql.cj.jdbc.ConnectionImpl.initializePropsFromServer(ConnectionImpl.java:1314)
at com.mysql.cj.jdbc.ConnectionImpl.connectOneTryOnly(ConnectionImpl.java:963)
at com.mysql.cj.jdbc.ConnectionImpl.createNewIO(ConnectionImpl.java:822)
... 7 more
原因是MySQL在高版本需要指明是否进行SSL连接。解决方案如下：
在mysql连接字符串url中加入ssl=true或者false即可，如下所示。
url=jdbc:mysql://127.0.0.1:3306/framework?characterEncoding=utf8&useSSL=true
三、出错信息
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)
at com.mysql.cj.jdbc.exceptions.SQLExceptionsMapping.translateException(SQLExceptionsMapping.java:64)
at com.mysql.cj.jdbc.ConnectionImpl.createNewIO(ConnectionImpl.java:832)
at com.mysql.cj.jdbc.ConnectionImpl.<init>(ConnectionImpl.java:456)
at com.mysql.cj.jdbc.ConnectionImpl.getInstance(ConnectionImpl.java:240)
at com.mysql.cj.jdbc.NonRegisteringDriver.connect(NonRegisteringDriver.java:207)
at java.sql.DriverManager.getConnection(Unknown Source)
at java.sql.DriverManager.getConnection(Unknown Source)
at 数据库操作.Conn.getConnection(Conn.java:16)
at 数据库操作.Conn.main(Conn.java:27)
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 sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
at sun.reflect.NativeConstructorAccessorImpl.newInstance(Unknown Source)
at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(Unknown Source)
at java.lang.reflect.Constructor.newInstance(Unknown Source)
at com.mysql.cj.exceptions.ExceptionFactory.createException(ExceptionFactory.java:61)
at com.mysql.cj.exceptions.ExceptionFactory.createException(ExceptionFactory.java:105)
at com.mysql.cj.exceptions.ExceptionFactory.createException(ExceptionFactory.java:151)
at com.mysql.cj.exceptions.ExceptionFactory.createCommunicationsException(ExceptionFactory.java:167)
at com.mysql.cj.protocol.a.NativeProtocol.negotiateSSLConnection(NativeProtocol.java:351)
at com.mysql.cj.protocol.a.NativeAuthenticationProvider.negotiateSSLConnection(NativeAuthenticationProvider.java:796)
at com.mysql.cj.protocol.a.NativeAuthenticationProvider.proceedHandshakeWithPluggableAuthentication(NativeAuthenticationProvider.java:503)
at com.mysql.cj.protocol.a.NativeAuthenticationProvider.connect(NativeAuthenticationProvider.java:220)
at com.mysql.cj.protocol.a.NativeProtocol.connect(NativeProtocol.java:1443)
at com.mysql.cj.NativeSession.connect(NativeSession.java:165)
at com.mysql.cj.jdbc.ConnectionImpl.connectOneTryOnly(ConnectionImpl.java:952)
at com.mysql.cj.jdbc.ConnectionImpl.createNewIO(ConnectionImpl.java:822)
... 7 more
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(Unknown Source)
at sun.security.ssl.SSLSocketImpl.fatal(Unknown Source)
at sun.security.ssl.Handshaker.fatalSE(Unknown Source)
at sun.security.ssl.Handshaker.fatalSE(Unknown Source)
at sun.security.ssl.ClientHandshaker.serverCertificate(Unknown Source)
at sun.security.ssl.ClientHandshaker.processMessage(Unknown Source)
at sun.security.ssl.Handshaker.processLoop(Unknown Source)
at sun.security.ssl.Handshaker.process_record(Unknown Source)
at sun.security.ssl.SSLSocketImpl.readRecord(Unknown Source)
at sun.security.ssl.SSLSocketImpl.performInitialHandshake(Unknown Source)
at sun.security.ssl.SSLSocketImpl.startHandshake(Unknown Source)
at sun.security.ssl.SSLSocketImpl.startHandshake(Unknown Source)
at com.mysql.cj.protocol.ExportControlled.performTlsHandshake(ExportControlled.java:315)
at com.mysql.cj.protocol.StandardSocketFactory.performTlsHandshake(StandardSocketFactory.java:206)
at com.mysql.cj.protocol.a.NativeSocketConnection.performTlsHandshake(NativeSocketConnection.java:99)
at com.mysql.cj.protocol.a.NativeProtocol.negotiateSSLConnection(NativeProtocol.java:347)
... 14 more
Caused by: java.security.cert.CertificateException: java.security.cert.CertPathValidatorException: Path does not chain with any of the trust anchors
at com.mysql.cj.protocol.ExportControlled$X509TrustManagerWrapper.checkServerTrusted(ExportControlled.java:379)
at sun.security.ssl.AbstractTrustManagerWrapper.checkServerTrusted(Unknown Source)
... 26 more
Caused by: java.security.cert.CertPathValidatorException: Path does not chain with any of the trust anchors
at sun.security.provider.certpath.PKIXCertPathValidator.validate(Unknown Source)
at sun.security.provider.certpath.PKIXCertPathValidator.engineValidate(Unknown Source)
at java.security.cert.CertPathValidator.validate(Unknown Source)
at com.mysql.cj.protocol.ExportControlled$X509TrustManagerWrapper.checkServerTrusted(ExportControlled.java:372)
... 27 more
原因：
应该是证书问题，把useSSL=true改为useSSL=false就好了。
