驱动加载成功 Thu Jun 08 22:43:18 CST 2023 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: No timezone mapping entry for 'GTM+8' at com.mysql.cj.jdbc.exceptions.SQLError.createSQLException(SQLError.java:127) at com.mysql.cj.jdbc.exceptions.SQLError.createSQLException(SQLError.java:95) at com.mysql.cj.jdbc.exceptions.SQLError.createSQLException(SQLError.java:87) at com.mysql.cj.jdbc.exceptions.SQLError.createSQLException(SQLError.java:61) at com.mysql.cj.jdbc.exceptions.SQLError.createSQLException(SQLError.java:71) at com.mysql.cj.jdbc.exceptions.SQLExceptionsMapping.translateException(SQLExceptionsMapping.java:85) at com.mysql.cj.jdbc.ConnectionImpl.createNewIO(ConnectionImpl.java:862) at com.mysql.cj.jdbc.ConnectionImpl.<init>(ConnectionImpl.java:444) at com.mysql.cj.jdbc.ConnectionImpl.getInstance(ConnectionImpl.java:230) at com.mysql.cj.jdbc.NonRegisteringDriver.connect(NonRegisteringDriver.java:226) at java.sql/java.sql.DriverManager.getConnection(DriverManager.java:681) at java.sql/java.sql.DriverManager.getConnection(DriverManager.java:229) at com.til.jdbc.JDBC.main(JDBC.java:16) Caused by: com.mysql.cj.exceptions.WrongArgumentException: No timezone mapping entry for 'GTM+8' at java.base/jdk.internal.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method) at java.base/jdk.internal.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:77) at java.base/jdk.internal.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45) at java.base/java.lang.ref

这是一个Java连接MySQL数据库时的异常报错。可以看到报错信息中提到了两个问题：

1. SSL连接警告：建议使用SSL连接，以确保连接的安全性。可以在连接字符串中设置useSSL=true来开启SSL连接，同时提供服务器证书以进行验证。

2. 时区映射错误：报错信息中的'GTM+8'应该是'GMT+8'的错误拼写，导致无法找到对应的时区映射。可以在连接字符串中添加serverTimezone参数指定正确的时区，例如：&serverTimezone=Asia/Shanghai。

解决方法：
1. 如果您的数据库不需要SSL连接，则可以在连接字符串中设置useSSL=false来关闭SSL连接。
2. 在连接字符串中添加serverTimezone参数，指定正确的时区。例如：&serverTimezone=Asia/Shanghai。

同时，还需要注意检查数据库账户和密码是否正确，以及数据库是否已启动。

相关问题

Thu Jun 13 22:42:10 CST 2024 WARN: Establishing SSL connection without server's identity verification is not recommended. According to MySQL

The message you're referring to is a warning in the MySQL logs, specifically related to establishing an SSL (Secure Sockets Layer) connection without verifying the server's identity. Here's what it means:

When you connect to a MySQL server using SSL, it's important to ensure that you are connecting to a trusted server and not an imposter. The warning "Establishing SSL connection without server's identity verification is not recommended" indicates that the client is attempting to establish a secure connection but isn't verifying the authenticity of the server certificate. This could potentially expose your data to man-in-the-middle attacks.

The reasons for this warning are:

1. Security: Verifying the server's identity ensures that you're connecting to the correct database and not an attacker masquerading as the server. It prevents unauthorized access or eavesdropping.

2. Data Integrity: SSL encryption also provides integrity, meaning that data exchanged between the client and server cannot be tampered with if the certificate is genuine.

To address this warning, you should consider these options:
- Obtain and install the server's trusted certificate, if it's missing or out of date.
- Use SSL/TLS configuration settings that enforce client authentication, so both client and server certificates need to be validated.
- Relax the security settings only when connecting to a trusted development or internal network where such verification is unnecessary.

Here are some related questions:

1. What is SSL/TLS and why is it used in MySQL connections?
2. How can I obtain and install a server certificate for my MySQL setup?
3. What are the consequences of ignoring SSL warnings during database interactions?

Tue Sep 26 11:56:15 CST 2023 WARN: Establishing SSL connection without server's identity verification is not recommended. According to MySQL

根据提供的引用内容，警告信息表明不建议在没有服务器身份验证的情况下建立SSL连接。根据MySQL 5.5.45，5.6.26和5.7.6的要求，如果没有设置显式选项，默认情况下必须建立SSL连接。为了符合不使用SSL的现有应用程序的要求，verifyServerCertificate属性被设置为'false'。你可以通过设置useSSL=false来显式禁用SSL，或者设置useSSL=true并为服务器证书验证提供信任存储。所以，根据警告信息，建议你在建立SSL连接时进行服务器身份验证。请确保提供了有效的证书并设置了useSSL=true。