HTTP Status 500 – Internal Server Error
Type Exception Report
Message Request processing failed; nested exception is org.apache.ibatis.exceptions.PersistenceException:
Description The server encountered an unexpected condition that prevented it from fulfilling the request.
Exception
org.springframework.web.util.NestedServletException: Request processing failed; nested exception is org.apache.ibatis.exceptions.PersistenceException:
### Error querying database. Cause: org.springframework.jdbc.CannotGetJdbcConnectionException: Failed to obtain JDBC Connection; nested exception is java.sql.SQLException: Cannot create PoolableConnectionFactory (Unknown initial character set index '255' received from server. Initial client character set can be forced via the 'characterEncoding' property.)
### The error may exist in file [D:\workspace\.metadata\.plugins\org.eclipse.wst.server.core\tmp0\wtpwebapps\HomeAddrseBooks\WEB-INF\classes\com\zg\dao\HomeAddrseMapper.xml]
### The error may involve homeInfosService.selAllHomeInfos
### The error occurred while executing a query
### Cause: org.springframework.jdbc.CannotGetJdbcConnectionException: Failed to obtain JDBC Connection; nested exception is java.sql.SQLException: Cannot create PoolableConnectionFactory (Unknown initial character set index '255' received from server. Initial client character set can be forced via the 'characterEncoding' property.)
org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:982)
org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:866)
javax.servlet.http.HttpServlet.service(HttpServlet.java:634)
org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:851)
javax.servlet.http.HttpServlet.service(HttpServlet.java:741)
org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:53)
Root Cause
org.apache.ibatis.exceptions.PersistenceException:
### Error querying database. Cause: org.springframework.jdbc.CannotGetJdbcConnectionException: Failed to obtain JDBC Connection; nested exception is java.sql.SQLException: Cannot create PoolableConnectionFactory (Unknown initial character set index '255' received from server. Initial client character set can be forced via the 'characterEncoding' property.)
### The error may exist in file [D:\workspace\.metadata\.plugins\org.eclipse.wst.server.core\tmp0\wtpwebapps\HomeAddrseBooks\WEB-INF\classes\com\zg\dao\HomeAddrseMapper.xml]
### The error may involve homeInfosService.selAllHomeInfos
### The error occurred while executing a query
### Cause: org.springframework.jdbc.CannotGetJdbcConnectionException: Failed to obtain JDBC Connection; nested exception is java.sql.SQLException: Cannot create PoolableConnectionFactory (Unknown initial character set index '255' received from server. Initial client character set can be forced via the 'characterEncoding' property.)
org.apache.ibatis.exceptions.ExceptionFactory.wrapException(ExceptionFactory.java:30)
org.apache.ibatis.session.defaults.DefaultSqlSession.selectList(DefaultSqlSession.java:150)
org.apache.ibatis.session.defaults.DefaultSqlSession.selectList(DefaultSqlSession.java:141)
org.apache.ibatis.session.defaults.DefaultSqlSession.selectList(DefaultSqlSession.java:136)
com.zg.dao.impl.HomeAddrseDaoImpl.selAllHomeInfos(HomeAddrseDaoImpl.java:26)
com.zg.service.impl.HomeAddrseService.selAllHomeInfos(HomeAddrseService.java:21)
com.zg.controllers.impl.HomeAddrseController.initPage(HomeAddrseController.java:33)
sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
java.lang.reflect.Method.invoke(Method.java:498)
org.springframework.web.method.support.InvocableHandlerMethod.doInvoke(InvocableHandlerMethod.java:209)
org.springframework.web.method.support.InvocableHandlerMethod.invokeForRequest(InvocableHandlerMethod.java:136)
org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:102)
org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandlerMethod(RequestMappingHandlerAdapter.java:877)
org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:783)
org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:87)
org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:991)
org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:925)
org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:974)
org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:866)
javax.servlet.http.HttpServlet.service(HttpServlet.java:634)
org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:851)
javax.servlet.http.HttpServlet.service(HttpServlet.java:741)
org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:53)
Root Cause
org.springframework.jdbc.CannotGetJdbcConnectionException: Failed to obtain JDBC Connection; nested exception is java.sql.SQLException: Cannot create PoolableConnectionFactory (Unknown initial character set index '255' received from server. Initial client character set can be forced via the 'characterEncoding' property.)
org.springframework.jdbc.datasource.DataSourceUtils.getConnection(DataSourceUtils.java:81)
org.mybatis.spring.transaction.SpringManagedTransaction.openConnection(SpringManagedTransaction.java:82)
org.mybatis.spring.transaction.SpringManagedTransaction.getConnection(SpringManagedTransaction.java:68)
org.apache.ibatis.executor.BaseExecutor.getConnection(BaseExecutor.java:338)
org.apache.ibatis.executor.SimpleExecutor.prepareStatement(SimpleExecutor.java:84)
org.apache.ibatis.executor.SimpleExecutor.doQuery(SimpleExecutor.java:62)
org.apache.ibatis.executor.BaseExecutor.queryFromDatabase(BaseExecutor.java:326)
org.apache.ibatis.executor.BaseExecutor.query(BaseExecutor.java:156)
org.apache.ibatis.executor.CachingExecutor.query(CachingExecutor.java:109)
org.apache.ibatis.executor.CachingExecutor.query(CachingExecutor.java:83)
org.apache.ibatis.session.defaults.DefaultSqlSession.selectList(DefaultSqlSession.java:148)
org.apache.ibatis.session.defaults.DefaultSqlSession.selectList(DefaultSqlSession.java:141)
org.apache.ibatis.session.defaults.DefaultSqlSession.selectList(DefaultSqlSession.java:136)
com.zg.dao.impl.HomeAddrseDaoImpl.selAllHomeInfos(HomeAddrseDaoImpl.java:26)
com.zg.service.impl.HomeAddrseService.selAllHomeInfos(HomeAddrseService.java:21)
com.zg.controllers.impl.HomeAddrseController.initPage(HomeAddrseController.java:33)
sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
java.lang.reflect.Method.invoke(Method.java:498)
org.springframework.web.method.support.InvocableHandlerMethod.doInvoke(InvocableHandlerMethod.java:209)
org.springframework.web.method.support.InvocableHandlerMethod.invokeForRequest(InvocableHandlerMethod.java:136)
org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:102)
org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandlerMethod(RequestMappingHandlerAdapter.java:877)
org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:783)
org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:87)
org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:991)
org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:925)
org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:974)
org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:866)
javax.servlet.http.HttpServlet.service(HttpServlet.java:634)
org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:851)
javax.servlet.http.HttpServlet.service(HttpServlet.java:741)
org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:53)
Root Cause
java.sql.SQLException: Cannot create PoolableConnectionFactory (Unknown initial character set index '255' received from server. Initial client character set can be forced via the 'characterEncoding' property.)
org.apache.commons.dbcp2.BasicDataSource.createPoolableConnectionFactory(BasicDataSource.java:2327)
org.apache.commons.dbcp2.BasicDataSource.createDataSource(BasicDataSource.java:2056)
org.apache.commons.dbcp2.BasicDataSource.getConnection(BasicDataSource.java:1533)
org.springframework.jdbc.datasource.DataSourceUtils.fetchConnection(DataSourceUtils.java:151)
org.springframework.jdbc.datasource.DataSourceUtils.doGetConnection(DataSourceUtils.java:115)
org.springframework.jdbc.datasource.DataSourceUtils.getConnection(DataSourceUtils.java:78)
org.mybatis.spring.transaction.SpringManagedTransaction.openConnection(SpringManagedTransaction.java:82)
org.mybatis.spring.transaction.SpringManagedTransaction.getConnection(SpringManagedTransaction.java:68)
org.apache.ibatis.executor.BaseExecutor.getConnection(BaseExecutor.java:338)
org.apache.ibatis.executor.SimpleExecutor.prepareStatement(SimpleExecutor.java:84)
org.apache.ibatis.executor.SimpleExecutor.doQuery(SimpleExecutor.java:62)
org.apache.ibatis.executor.BaseExecutor.queryFromDatabase(BaseExecutor.java:326)
org.apache.ibatis.executor.BaseExecutor.query(BaseExecutor.java:156)
org.apache.ibatis.executor.CachingExecutor.query(CachingExecutor.java:109)
org.apache.ibatis.executor.CachingExecutor.query(CachingExecutor.java:83)
org.apache.ibatis.session.defaults.DefaultSqlSession.selectList(DefaultSqlSession.java:148)
org.apache.ibatis.session.defaults.DefaultSqlSession.selectList(DefaultSqlSession.java:141)
org.apache.ibatis.session.defaults.DefaultSqlSession.selectList(DefaultSqlSession.java:136)
com.zg.dao.impl.HomeAddrseDaoImpl.selAllHomeInfos(HomeAddrseDaoImpl.java:26)
com.zg.service.impl.HomeAddrseService.selAllHomeInfos(HomeAddrseService.java:21)
com.zg.controllers.impl.HomeAddrseController.initPage(HomeAddrseController.java:33)
sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
java.lang.reflect.Method.invoke(Method.java:498)
org.springframework.web.method.support.InvocableHandlerMethod.doInvoke(InvocableHandlerMethod.java:209)
org.springframework.web.method.support.InvocableHandlerMethod.invokeForRequest(InvocableHandlerMethod.java:136)
org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:102)
org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandlerMethod(RequestMappingHandlerAdapter.java:877)
org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:783)
org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:87)
org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:991)
org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:925)
org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:974)
org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:866)
javax.servlet.http.HttpServlet.service(HttpServlet.java:634)
org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:851)
javax.servlet.http.HttpServlet.service(HttpServlet.java:741)
org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:53)
Root Cause
java.sql.SQLException: Unknown initial character set index '255' received from server. Initial client character set can be forced via the 'characterEncoding' property.
com.mysql.jdbc.SQLError.createSQLException(SQLError.java:1055)
com.mysql.jdbc.SQLError.createSQLException(SQLError.java:956)
com.mysql.jdbc.SQLError.createSQLException(SQLError.java:926)
com.mysql.jdbc.ConnectionImpl.configureClientCharacterSet(ConnectionImpl.java:1689)
com.mysql.jdbc.ConnectionImpl.initializePropsFromServer(ConnectionImpl.java:3444)
com.mysql.jdbc.ConnectionImpl.createNewIO(ConnectionImpl.java:2062)
com.mysql.jdbc.ConnectionImpl.<init>(ConnectionImpl.java:723)
com.mysql.jdbc.JDBC4Connection.<init>(JDBC4Connection.java:46)
sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62)
sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
java.lang.reflect.Constructor.newInstance(Constructor.java:423)
com.mysql.jdbc.Util.handleNewInstance(Util.java:406)
com.mysql.jdbc.ConnectionImpl.getInstance(ConnectionImpl.java:302)
com.mysql.jdbc.NonRegisteringDriver.connect(NonRegisteringDriver.java:282)
org.apache.commons.dbcp2.DriverConnectionFactory.createConnection(DriverConnectionFactory.java:38)
org.apache.commons.dbcp2.PoolableConnectionFactory.makeObject(PoolableConnectionFactory.java:260)
org.apache.commons.dbcp2.BasicDataSource.validateConnectionFactory(BasicDataSource.java:2337)
org.apache.commons.dbcp2.BasicDataSource.createPoolableConnectionFactory(BasicDataSource.java:2323)
org.apache.commons.dbcp2.BasicDataSource.createDataSource(BasicDataSource.java:2056)
org.apache.commons.dbcp2.BasicDataSource.getConnection(BasicDataSource.java:1533)
org.springframework.jdbc.datasource.DataSourceUtils.fetchConnection(DataSourceUtils.java:151)
org.springframework.jdbc.datasource.DataSourceUtils.doGetConnection(DataSourceUtils.java:115)
org.springframework.jdbc.datasource.DataSourceUtils.getConnection(DataSourceUtils.java:78)
org.mybatis.spring.transaction.SpringManagedTransaction.openConnection(SpringManagedTransaction.java:82)
org.mybatis.spring.transaction.SpringManagedTransaction.getConnection(SpringManagedTransaction.java:68)
org.apache.ibatis.executor.BaseExecutor.getConnection(BaseExecutor.java:338)
org.apache.ibatis.executor.SimpleExecutor.prepareStatement(SimpleExecutor.java:84)
org.apache.ibatis.executor.SimpleExecutor.doQuery(SimpleExecutor.java:62)
org.apache.ibatis.executor.BaseExecutor.queryFromDatabase(BaseExecutor.java:326)
org.apache.ibatis.executor.BaseExecutor.query(BaseExecutor.java:156)
org.apache.ibatis.executor.CachingExecutor.query(CachingExecutor.java:109)
org.apache.ibatis.executor.CachingExecutor.query(CachingExecutor.java:83)
org.apache.ibatis.session.defaults.DefaultSqlSession.selectList(DefaultSqlSession.java:148)
org.apache.ibatis.session.defaults.DefaultSqlSession.selectList(DefaultSqlSession.java:141)
org.apache.ibatis.session.defaults.DefaultSqlSession.selectList(DefaultSqlSession.java:136)
com.zg.dao.impl.HomeAddrseDaoImpl.selAllHomeInfos(HomeAddrseDaoImpl.java:26)
com.zg.service.impl.HomeAddrseService.selAllHomeInfos(HomeAddrseService.java:21)
com.zg.controllers.impl.HomeAddrseController.initPage(HomeAddrseController.java:33)
sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
java.lang.reflect.Method.invoke(Method.java:498)
org.springframework.web.method.support.InvocableHandlerMethod.doInvoke(InvocableHandlerMethod.java:209)
org.springframework.web.method.support.InvocableHandlerMethod.invokeForRequest(InvocableHandlerMethod.java:136)
org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:102)
org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandlerMethod(RequestMappingHandlerAdapter.java:877)
org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:783)
org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:87)
org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:991)
org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:925)
org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:974)
org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:866)
javax.servlet.http.HttpServlet.service(HttpServlet.java:634)
org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:851)
javax.servlet.http.HttpServlet.service(HttpServlet.java:741)
org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:53)
Note The full stack trace of the root cause is available in the server logs.
Apache Tomcat/9.0.8
報錯原因：1.數據庫編碼，程序編碼，程序編碼不一致 2.編碼類型無法識別
通過查詢可知數據庫編碼為utf8mb4.
而服務器的編碼和程序的編碼為utf8.
解決方法：替換了數據庫驅動jar包mysql-connector-java-6.0.6.jar
然后報如下問題：
Unknown system variable 'query_cache_size'
問題原因：mysql使用了最新的8.0版本 數據庫驅動版本不匹配
解決方法：替換了數據庫驅動jar包mysql-connector-java-8.0.11.jar 該JAR包依賴protobuf-java-3.5.1.jar 因此也要加上
連接SQL常見問題
useSSL
后台警告信息
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. 網上很多地方提示加上 useSSL=false 就可以了， 但是如果只是加上這個的話， 會報錯如下：
com.mysql.jdbc.exceptions.jdbc4.CommunicationsException: Communications link failure
The last packet successfully received from the server was 250 milliseconds ago. The last packet sent successfully to the server was 242 milliseconds ago. at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method) ~[na:1.8.0_101] at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62) ~[na:1.8.0_101] at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45) ~[na:1.8.0_101] at java.lang.reflect.Constructor.newInstance(Constructor.java:423) ~[na:1.8.0_101] xxx 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_101] at sun.security.ssl.SSLSocketImpl.fatal(SSLSocketImpl.java:1949) ~[na:1.8.0_101] at sun.security.ssl.Handshaker.fatalSE(Handshaker.java:302) ~[na:1.8.0_101] at sun.security.ssl.Handshaker.fatalSE(Handshaker.java:296) ~[na:1.8.0_101] at sun.security.ssl.ClientHandshaker.serverCertificate(ClientHandshaker.java:1509) ~[na:1.8.0_101] at sun.security.ssl.ClientHandshaker.processMessage(ClientHandshaker.java:216) ~[na:1.8.0_101] at sun.security.ssl.Handshaker.processLoop(Handshaker.java:979) ~[na:1.8.0_101] at sun.security.ssl.Handshaker.process_record(Handshaker.java:914) ~[na:1.8.0_101] at sun.security.ssl.SSLSocketImpl.readRecord(SSLSocketImpl.java:1062) ~[na:1.8.0_101] at sun.security.ssl.SSLSocketImpl.performInitialHandshake(SSLSocketImpl.java:1375) ~[na:1.8.0_101] at sun.security.ssl.SSLSocketImpl.startHandshake(SSLSocketImpl.java:1403) ~[na:1.8.0_101] at sun.security.ssl.SSLSocketImpl.startHandshake(SSLSocketImpl.java:1387) ~[na:1.8.0_101] at com.mysql.jdbc.ExportControlled.transformSocketToSSLSocket(ExportControlled.java:186) ~[mysql-connector-java-5.1.46.jar:5.1.46] ... 105 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$X509TrustManagerWrapper.checkServerTrusted(ExportControlled.java:302) ~[mysql-connector-java-5.1.46.jar:5.1.46] at sun.security.ssl.AbstractTrustManagerWrapper.checkServerTrusted(SSLContextImpl.java:922) ~[na:1.8.0_101] at sun.security.ssl.ClientHandshaker.serverCertificate(ClientHandshaker.java:1491) ~[na:1.8.0_101] ... 113 common frames omitted Caused by: java.security.cert.CertPathValidatorException: Path does not chain with any of the trust anchors at sun.security.provider.certpath.PKIXCertPathValidator.validate(PKIXCertPathValidator.java:153) ~[na:1.8.0_101] at sun.security.provider.certpath.PKIXCertPathValidator.engineValidate(PKIXCertPathValidator.java:79) ~[na:1.8.0_101] at java.security.cert.CertPathValidator.validate(CertPathValidator.java:292) ~[na:1.8.0_101] at com.mysql.jdbc.ExportControlled$X509TrustManagerWrapper.checkServerTrusted(ExportControlled.java:295) ~[mysql-connector-java-5.1.46.jar:5.1.46] ... 115 common frames omitted 解決方法如下：
在 url 后面加上 autoReconnect=true&useSSL=false url: jdbc:mysql://10.132.241.120:3306/vue?characterEncoding=utf8&autoReconnect=true&useSSL=false Unknown system variable 'query_cache_size'
后台報錯信息如下：
java.sql.SQLException: Unknown system variable 'query_cache_size' 這個錯是 數據庫驅動版本和 數據庫不一致導致的。解決方法如下：
根據自己的數據庫版本去這個地址選擇合適的驅動版本
https://mvnrepository.com/artifact/mysql/mysql-connector-java 比如我的數據庫版本是 8.0.11，那么對應的驅動為: <dependency> <groupId>mysql</groupId> <artifactId>mysql-connector-java</artifactId> <version>8.0.11</version> </dependency> timeZone亂碼
報錯信息
java.sql.SQLException: The server time zone value 'Öйú±ê׼ʱ¼ä' 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. 這個錯是因為 庫的時間與系統時間不符導致的。解決方法如下：
在url 后面加上 serverTimezone=GMT
url: jdbc:mysql://localhost:3306/admin?characterEncoding=utf-8&autoReconnect=true&useSSL=false&serverTimezone=GMT 'hibernate.dialect' not set
在Spring Boot下使用JPA報錯：'hibernate.dialect' not set，報錯信息如下：
Caused by: org.hibernate.HibernateException: Access to DialectResolutionInfo cannot be null when 'hibernate.dialect' not set at org.hibernate.engine.jdbc.dialect.internal.DialectFactoryImpl.determineDialect(DialectFactoryImpl.java:104) at org.hibernate.engine.jdbc.dialect.internal.DialectFactoryImpl.buildDialect(DialectFactoryImpl.java:71) at org.hibernate.engine.jdbc.internal.JdbcServicesImpl.configure(JdbcServicesImpl.java:205) at org.hibernate.boot.registry.internal.StandardServiceRegistryImpl.configureService(StandardServiceRegistryImpl.java:111) at org.hibernate.service.internal.AbstractServiceRegistryImpl.initializeService(AbstractServiceRegistryImpl.java:234) at org.hibernate.service.internal.AbstractServiceRegistryImpl.getService(AbstractServiceRegistryImpl.java:206) at org.hibernate.cfg.Configuration.buildTypeRegistrations(Configuration.java:1885) at org.hibernate.cfg.Configuration.buildSessionFactory(Configuration.java:1843) at org.hibernate.jpa.boot.internal.EntityManagerFactoryBuilderImpl$4.perform(EntityManagerFactoryBuilderImpl.java:850) at org.hibernate.jpa.boot.internal.EntityManagerFactoryBuilderImpl$4.perform(EntityManagerFactoryBuilderImpl.java:843) at org.hibernate.boot.registry.classloading.internal.ClassLoaderServiceImpl.withTccl(ClassLoaderServiceImpl.java:398) at org.hibernate.jpa.boot.internal.EntityManagerFactoryBuilderImpl.build(EntityManagerFactoryBuilderImpl.java:842) at org.hibernate.jpa.HibernatePersistenceProvider.createContainerEntityManagerFactory(HibernatePersistenceProvider.java:152) at org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean.createNativeEntityManagerFactory(LocalContainerEntityManagerFactoryBean.java:336) at org.springframework.orm.jpa.AbstractEntityManagerFactoryBean.afterPropertiesSet(AbstractEntityManagerFactoryBean.java:318) at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.invokeInitMethods(AbstractAutowireCapableBeanFactory.java:1613) at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1550) ... 21 more 解決方法：
在 application.yaml 文件中添加以下內容 jpa: database-platform: org.hibernate.dialect.MySQL5Dialect