我有一个每20分钟运行一次的计划任务，通过＆＃34; @Scheduled（cron =＆＃34; 0 0/20 * * *？＆＃34;）＆＃34;基于弹簧靴。在此任务中，我需要从mysql中搜索一些数据，然后将它们保存到redis中。以下是我的数据库配置：
mybatis.configuration.map-underscore-to-camel-case=true
spring.datasource.type=com.alibaba.druid.pool.DruidDataSource
#spring.datasource.driver-class-name=com.mysql.jdbc.Driver
spring.datasource.initialSize=1
spring.datasource.minIdle=1
spring.datasource.maxActive=20
spring.datasource.maxWait=60000
spring.datasource.timeBetweenEvictionRunsMillis=60000
spring.datasource.minEvictableIdleTimeMillis=300000
spring.datasource.validationQuery=SELECT 'x'
spring.datasource.testWhileIdle=true
spring.datasource.testOnBorrow=false
spring.datasource.testOnReturn=false
spring.datasource.poolPreparedStatements=true
spring.datasource.maxPoolPreparedStatementPerConnectionSize=20
spring.datasource.filters=stat,wall,slf4j
spring.datasource.initialize=false
mysql版本是v5.7.19。我的mysql-connector-java版本是5.1.41。我的德鲁伊版本是1.0.29。 JDK是18岁。
我的问题是我的预定任务有时只能成功执行。例如，我的应用程序运行24小时。必须有一到两次执行任务失败。但我有另一个计划任务，每10分钟运行一次，需要通过相同的配置连接到同一个mysql，每次都成功。 任务失败时，日志信息为：
2018-02-14 02:20:00,003 [pool-5-thread-1] INFO c.x.r.b.r.provider.YourFavoriates Method:executeItemInfoUpdateTaskRun Line:359 - Host IP 10.189.145.64: Scheduled task(executeItemInfoUpdateTask) is begining to save the available skuId information of all storeId from mysql to cache.
2018-02-14 02:20:00,026 [pool-5-thread-1] INFO o.s.b.f.xml.XmlBeanDefinitionReader Method:loadBeanDefinitions Line:317 - Loading XML bean definitions from class path resource [org/springframework/jdbc/support/sql-error-codes.xml]
2018-02-14 02:20:00,060 [pool-5-thread-1] INFO o.s.j.support.SQLErrorCodesFactory Method:<init> Line:127 - SQLErrorCodes loaded: [DB2, Derby, H2, HSQL, Informix, MS-SQL, MySQL, Oracle, PostgreSQL, Sybase, Hana]
2018-02-14 02:20:00,067 [pool-5-thread-1] WARN o.s.j.support.SQLErrorCodesFactory Method:getErrorCodes Line:218 - Error while extracting database name - falling back to empty error codes
org.springframework.jdbc.support.MetaDataAccessException: Error while extracting DatabaseMetaData; nested exception is com.mysql.jdbc.exceptions.jdbc4.MySQLNonTransientConnectionException: No operations allowed after connection closed.
at org.springframework.jdbc.support.JdbcUtils.extractDatabaseMetaData(JdbcUtils.java:342)
at org.springframework.jdbc.support.JdbcUtils.extractDatabaseMetaData(JdbcUtils.java:366)
at org.springframework.jdbc.support.SQLErrorCodesFactory.getErrorCodes(SQLErrorCodesFactory.java:212)
at org.springframework.jdbc.support.SQLErrorCodeSQLExceptionTranslator.setDataSource(SQLErrorCodeSQLExceptionTranslator.java:134)
at org.springframework.jdbc.support.SQLErrorCodeSQLExceptionTranslator.<init>(SQLErrorCodeSQLExceptionTranslator.java:97)
at org.mybatis.spring.MyBatisExceptionTranslator.initExceptionTranslator(MyBatisExceptionTranslator.java:87)
at org.mybatis.spring.MyBatisExceptionTranslator.translateExceptionIfPossible(MyBatisExceptionTranslator.java:72)
at org.mybatis.spring.SqlSessionTemplate$SqlSessionInterceptor.invoke(SqlSessionTemplate.java:446)
at com.sun.proxy.$Proxy86.selectOne(Unknown Source)
at org.mybatis.spring.SqlSessionTemplate.selectOne(SqlSessionTemplate.java:166)
at org.apache.ibatis.binding.MapperMethod.execute(MapperMethod.java:82)
at org.apache.ibatis.binding.MapperProxy.invoke(MapperProxy.java:59)
at com.sun.proxy.$Proxy87.countForQueryAvailableSku(Unknown Source)
at com.xstore.recommend.biz.recommend.provider.YourFavoriates.getAvailableItems(YourFavoriates.java:68)
at com.xstore.recommend.biz.recommend.provider.YourFavoriates.executeItemInfoUpdateTaskRun(YourFavoriates.java:360)
at com.xstore.recommend.biz.recommend.provider.YourFavoriates.executeItemInfoUpdateTask(YourFavoriates.java:467)
at sun.reflect.GeneratedMethodAccessor126.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:497)
at org.springframework.scheduling.support.ScheduledMethodRunnable.run(ScheduledMethodRunnable.java:65)
at org.springframework.scheduling.support.DelegatingErrorHandlingRunnable.run(DelegatingErrorHandlingRunnable.java:54)
at org.springframework.scheduling.concurrent.ReschedulingRunnable.run(ReschedulingRunnable.java:81)
at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511)
at java.util.concurrent.FutureTask.run(FutureTask.java:266)
at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.access$201(ScheduledThreadPoolExecutor.java:180)
at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.run(ScheduledThreadPoolExecutor.java:293)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
at java.lang.Thread.run(Thread.java:745)
Caused by: com.mysql.jdbc.exceptions.jdbc4.MySQLNonTransientConnectionException: No operations allowed after connection closed.
at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62)
at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
at java.lang.reflect.Constructor.newInstance(Constructor.java:422)
at com.mysql.jdbc.Util.handleNewInstance(Util.java:425)
at com.mysql.jdbc.Util.getInstance(Util.java:408)
at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:918)
at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:897)
at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:886)
at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:860)
at com.mysql.jdbc.ConnectionImpl.throwConnectionClosedException(ConnectionImpl.java:1198)
at com.mysql.jdbc.ConnectionImpl.checkClosed(ConnectionImpl.java:1193)
at com.mysql.jdbc.ConnectionImpl.getMetaData(ConnectionImpl.java:2903)
at com.mysql.jdbc.ConnectionImpl.getMetaData(ConnectionImpl.java:2898)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:497)
at org.apache.tomcat.jdbc.pool.ProxyConnection.invoke(ProxyConnection.java:126)
at org.apache.tomcat.jdbc.pool.JdbcInterceptor.invoke(JdbcInterceptor.java:108)
at org.apache.tomcat.jdbc.pool.interceptor.AbstractCreateStatementInterceptor.invoke(AbstractCreateStatementInterceptor.java:70)
at org.apache.tomcat.jdbc.pool.JdbcInterceptor.invoke(JdbcInterceptor.java:108)
at org.apache.tomcat.jdbc.pool.DisposableConnectionFacade.invoke(DisposableConnectionFacade.java:81)
at com.sun.proxy.$Proxy118.getMetaData(Unknown Source)
at org.springframework.jdbc.support.JdbcUtils.extractDatabaseMetaData(JdbcUtils.java:331)
... 28 common frames omitted
Caused by: com.mysql.jdbc.exceptions.jdbc4.CommunicationsException: The last packet successfully received from the server was 31,199,913 milliseconds ago. The last packet sent successfully to the server was 31,199,929 milliseconds ago. is longer than the server configured value of 'wait_timeout'. You should consider either expiring and/or testing connection validity before use in your application, increasing the server configured values for client timeouts, or using the Connector/J connection property 'autoReconnect=true' to avoid this problem.
at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62)
at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
at java.lang.reflect.Constructor.newInstance(Constructor.java:422)
at com.mysql.jdbc.Util.handleNewInstance(Util.java:425)
at com.mysql.jdbc.SQLError.createCommunicationsException(SQLError.java:989)
at com.mysql.jdbc.MysqlIO.send(MysqlIO.java:3746)
at com.mysql.jdbc.MysqlIO.sendCommand(MysqlIO.java:2509)
at com.mysql.jdbc.MysqlIO.sqlQueryDirect(MysqlIO.java:2680)
at com.mysql.jdbc.ConnectionImpl.execSQL(ConnectionImpl.java:2501)
at com.mysql.jdbc.PreparedStatement.executeInternal(PreparedStatement.java:1858)
at com.mysql.jdbc.PreparedStatement.execute(PreparedStatement.java:1197)
at sun.reflect.GeneratedMethodAccessor119.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:497)
at org.apache.tomcat.jdbc.pool.StatementFacade$StatementProxy.invoke(StatementFacade.java:138)
at com.sun.proxy.$Proxy119.execute(Unknown Source)
at org.apache.ibatis.executor.statement.PreparedStatementHandler.query(PreparedStatementHandler.java:63)
at org.apache.ibatis.executor.statement.RoutingStatementHandler.query(RoutingStatementHandler.java:79)
at org.apache.ibatis.executor.SimpleExecutor.doQuery(SimpleExecutor.java:63)
at org.apache.ibatis.executor.BaseExecutor.queryFromDatabase(BaseExecutor.java:324)
at org.apache.ibatis.executor.BaseExecutor.query(BaseExecutor.java:156)
at org.apache.ibatis.executor.CachingExecutor.query(CachingExecutor.java:109)
at org.apache.ibatis.executor.CachingExecutor.query(CachingExecutor.java:83)
at org.apache.ibatis.session.defaults.DefaultSqlSession.selectList(DefaultSqlSession.java:148)
at org.apache.ibatis.session.defaults.DefaultSqlSession.selectList(DefaultSqlSession.java:141)
at org.apache.ibatis.session.defaults.DefaultSqlSession.selectOne(DefaultSqlSession.java:77)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:497)
at org.mybatis.spring.SqlSessionTemplate$SqlSessionInterceptor.invoke(SqlSessionTemplate.java:433)
... 21 common frames omitted
Caused by: java.net.SocketException: 断开的管道
at java.net.SocketOutputStream.socketWrite0(Native Method)
at java.net.SocketOutputStream.socketWrite(SocketOutputStream.java:109)
at java.net.SocketOutputStream.write(SocketOutputStream.java:153)
at java.io.BufferedOutputStream.flushBuffer(BufferedOutputStream.java:82)
at java.io.BufferedOutputStream.flush(BufferedOutputStream.java:140)
at com.mysql.jdbc.MysqlIO.send(MysqlIO.java:3728)
... 46 common frames omitted
2018-02-14 02:20:00,069 [pool-5-thread-1] ERROR c.x.r.b.r.provider.YourFavoriates Method:executeItemInfoUpdateTask Line:469 - Exception while executing executeItemInfoUpdateTaskRun.
org.springframework.dao.RecoverableDataAccessException:
### Error querying database. Cause: com.mysql.jdbc.exceptions.jdbc4.CommunicationsException: The last packet successfully received from the server was 31,199,913 milliseconds ago. The last packet sent successfully to the server was 31,199,929 milliseconds ago. is longer than the server configured value of 'wait_timeout'. You should consider either expiring and/or testing connection validity before use in your application, increasing the server configured values for client timeouts, or using the Connector/J connection property 'autoReconnect=true' to avoid this problem.
### The error may exist in URL [jar:file:/home/export/App/intelligenceRS.man.7fresh.com/WEB-INF/lib/xstore-intelligence-service-1.0.0-SNAPSHOT.jar!/mapper/popMd/PopMdMapper.xml]
### The error may involve defaultParameterMap
### The error occurred while setting parameters
### SQL: select count(1) from search_base_data where isIgnoreSearchVisible = 0 and has_stock = 1 and search_invisible = 1
### Cause: com.mysql.jdbc.exceptions.jdbc4.CommunicationsException: The last packet successfully received from the server was 31,199,913 milliseconds ago. The last packet sent successfully to the server was 31,199,929 milliseconds ago. is longer than the server configured value of 'wait_timeout'. You should consider either expiring and/or testing connection validity before use in your application, increasing the server configured values for client timeouts, or using the Connector/J connection property 'autoReconnect=true' to avoid this problem.
; SQL []; The last packet successfully received from the server was 31,199,913 milliseconds ago. The last packet sent successfully to the server was 31,199,929 milliseconds ago. is longer than the server configured value of 'wait_timeout'. You should consider either expiring and/or testing connection validity before use in your application, increasing the server configured values for client timeouts, or using the Connector/J connection property 'autoReconnect=true' to avoid this problem.; nested exception is com.mysql.jdbc.exceptions.jdbc4.CommunicationsException: The last packet successfully received from the server was 31,199,913 milliseconds ago. The last packet sent successfully to the server was 31,199,929 milliseconds ago. is longer than the server configured value of 'wait_timeout'. You should consider either expiring and/or testing connection validity before use in your application, increasing the server configured values for client timeouts, or using the Connector/J connection property 'autoReconnect=true' to avoid this problem.
at org.springframework.jdbc.support.SQLExceptionSubclassTranslator.doTranslate(SQLExceptionSubclassTranslator.java:98)
at org.springframework.jdbc.support.AbstractFallbackSQLExceptionTranslator.translate(AbstractFallbackSQLExceptionTranslator.java:73)
at org.springframework.jdbc.support.AbstractFallbackSQLExceptionTranslator.translate(AbstractFallbackSQLExceptionTranslator.java:81)
at org.mybatis.spring.MyBatisExceptionTranslator.translateExceptionIfPossible(MyBatisExceptionTranslator.java:73)
at org.mybatis.spring.SqlSessionTemplate$SqlSessionInterceptor.invoke(SqlSessionTemplate.java:446)
at com.sun.proxy.$Proxy86.selectOne(Unknown Source)
at org.mybatis.spring.SqlSessionTemplate.selectOne(SqlSessionTemplate.java:166)
at org.apache.ibatis.binding.MapperMethod.execute(MapperMethod.java:82)
at org.apache.ibatis.binding.MapperProxy.invoke(MapperProxy.java:59)
at com.sun.proxy.$Proxy87.countForQueryAvailableSku(Unknown Source)
at com.xstore.recommend.biz.recommend.provider.YourFavoriates.getAvailableItems(YourFavoriates.java:68)
at com.xstore.recommend.biz.recommend.provider.YourFavoriates.executeItemInfoUpdateTaskRun(YourFavoriates.java:360)
at com.xstore.recommend.biz.recommend.provider.YourFavoriates.executeItemInfoUpdateTask(YourFavoriates.java:467)
at sun.reflect.GeneratedMethodAccessor126.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:497)
at org.springframework.scheduling.support.ScheduledMethodRunnable.run(ScheduledMethodRunnable.java:65)
at org.springframework.scheduling.support.DelegatingErrorHandlingRunnable.run(DelegatingErrorHandlingRunnable.java:54)
at org.springframework.scheduling.concurrent.ReschedulingRunnable.run(ReschedulingRunnable.java:81)
at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511)
at java.util.concurrent.FutureTask.run(FutureTask.java:266)
at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.access$201(ScheduledThreadPoolExecutor.java:180)
at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.run(ScheduledThreadPoolExecutor.java:293)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
at java.lang.Thread.run(Thread.java:745)
Caused by: com.mysql.jdbc.exceptions.jdbc4.CommunicationsException: The last packet successfully received from the server was 31,199,913 milliseconds ago. The last packet sent successfully to the server was 31,199,929 milliseconds ago. is longer than the server configured value of 'wait_timeout'. You should consider either expiring and/or testing connection validity before use in your application, increasing the server configured values for client timeouts, or using the Connector/J connection property 'autoReconnect=true' to avoid this problem.
at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62)
at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
at java.lang.reflect.Constructor.newInstance(Constructor.java:422)
at com.mysql.jdbc.Util.handleNewInstance(Util.java:425)
at com.mysql.jdbc.SQLError.createCommunicationsException(SQLError.java:989)
at com.mysql.jdbc.MysqlIO.send(MysqlIO.java:3746)
at com.mysql.jdbc.MysqlIO.sendCommand(MysqlIO.java:2509)
at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
at com.mysql.jdbc.MysqlIO.sqlQueryDirect(MysqlIO.java:2680)
at com.mysql.jdbc.ConnectionImpl.execSQL(ConnectionImpl.java:2501)
at com.mysql.jdbc.PreparedStatement.executeInternal(PreparedStatement.java:1858)
at com.mysql.jdbc.PreparedStatement.execute(PreparedStatement.java:1197)
at sun.reflect.GeneratedMethodAccessor119.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:497)
at org.apache.tomcat.jdbc.pool.StatementFacade$StatementProxy.invoke(StatementFacade.java:138)
at com.sun.proxy.$Proxy119.execute(Unknown Source)
at org.apache.ibatis.executor.statement.PreparedStatementHandler.query(PreparedStatementHandler.java:63)
at org.apache.ibatis.executor.statement.RoutingStatementHandler.query(RoutingStatementHandler.java:79)
at org.apache.ibatis.executor.SimpleExecutor.doQuery(SimpleExecutor.java:63)
at org.apache.ibatis.executor.BaseExecutor.queryFromDatabase(BaseExecutor.java:324)
at org.apache.ibatis.executor.BaseExecutor.query(BaseExecutor.java:156)
at org.apache.ibatis.executor.CachingExecutor.query(CachingExecutor.java:109)
at org.apache.ibatis.executor.CachingExecutor.query(CachingExecutor.java:83)
at org.apache.ibatis.session.defaults.DefaultSqlSession.selectList(DefaultSqlSession.java:148)
at org.apache.ibatis.session.defaults.DefaultSqlSession.selectList(DefaultSqlSession.java:141)
at org.apache.ibatis.session.defaults.DefaultSqlSession.selectOne(DefaultSqlSession.java:77)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:497)
at org.mybatis.spring.SqlSessionTemplate$SqlSessionInterceptor.invoke(SqlSessionTemplate.java:433)
... 21 common frames omitted
Caused by: java.net.SocketException: 断开的管道
at java.net.SocketOutputStream.socketWrite0(Native Method)
at java.net.SocketOutputStream.socketWrite(SocketOutputStream.java:109)
at java.net.SocketOutputStream.write(SocketOutputStream.java:153)
at java.io.BufferedOutputStream.flushBuffer(BufferedOutputStream.java:82)
at java.io.BufferedOutputStream.flush(BufferedOutputStream.java:140)
at com.mysql.jdbc.MysqlIO.send(MysqlIO.java:3728)
... 46 common frames omitted
真正的原因是什么？我从互联网上搜索答案。很多人说要将testOnBorrow改为true，或者延长mysql连接超时等等。这些答案不能满足我的问题。所以，请帮帮我。我被这个问题困扰了一个星期。
答案 0 :(得分：1)
了解正在使用的连接池非常重要。
提供的有关不同数据库类型的信息有点不足，但这是我的初步分析和一些有用的重要指示：
1）如果您使用的是spring数据jpa或者入门jpa，则很可能默认情况下使用的是tomcat连接池。
以下是一些更多细节（很好的阅读）：https://docs.spring.io/spring-boot/docs/current/reference/html/boot-features-sql.html
顺便说一下，检查这个的简单方法是在日志中，你会看到org.apache.tomcat.jdbc.pool。* logs。
2）其次，如果它是＃1中所述，则可以通过application.properties应用连接池属性：
spring.datasource.tomcat.min-idle=1
spring.datasource.tomcat.validation-query= select 1
spring.datasource.tomcat.validation-interval=30000
spring.datasource.tomcat.remove-abandoned-timeout=120
spring.datasource.tomcat.remove-abandoned=true
spring.datasource.tomcat.log-abandoned=true
3）最后，但需要注意的是数据源类型：
spring.datasource.type=com.alibaba.druid.pool.DruidDataSource
Haven实际上已经尝试过了，但我相信你在application.properties中使用的属性正在应用于tomcat池，这是不确定的，如果它在应用程序中是否被使用（信息不足） ）。
无论如何，回到手头的问题，你将不得不看看实际的数据源配置，实际上＆＃34;实际上＆＃34;应用于您的tx连接，请查看以下类以了解正在使用的实际属性：
你也可以给下面的测试有点属性：
#Druid 数据源配置，继承spring.datasource.* 配置，相同则覆盖
spring.datasource.druid.initial-size=2
spring.datasource.druid.max-active=30
spring.datasource.druid.min-idle=2
spring.datasource.druid.max-wait=1234
spring.datasource.druid.pool-prepared-statements=true
spring.datasource.druid.max-pool-prepared-statement-per-connection-size=5
#spring.datasource.druid.max-open-prepared-statements= #等价于上面的max-pool-prepared-statement-per-connection-size
spring.datasource.druid.validation-query=select 1
spring.datasource.druid.validation-query-timeout=1
spring.datasource.druid.test-on-borrow=true
spring.datasource.druid.test-on-return=true
希望有所帮助!!
答案 1 :(得分：0)
在数据库连接之前取消redis操作后，没有再次发生异常。我不确定他们之间是否有任何关系。这很奇怪。必须有一些我无法找到的真正原因。