jdbc开始失败

Question

访问Web服务时，我会随机收到此错误。它很难复制，并且一旦刷新它，一切都会按预期运行。

Caused by: org.hibernate.exception.JDBCConnectionException: could not execute query
        at org.hibernate.exception.SQLStateConverter.convert(SQLStateConverter.java:97)
        at org.hibernate.exception.JDBCExceptionHelper.convert(JDBCExceptionHelper.java:66)
        at org.hibernate.loader.Loader.doList(Loader.java:2235)
        at org.hibernate.loader.Loader.listIgnoreQueryCache(Loader.java:2129)
        at org.hibernate.loader.Loader.list(Loader.java:2124)
        at org.hibernate.loader.criteria.CriteriaLoader.list(CriteriaLoader.java:118)
        at org.hibernate.impl.SessionImpl.list(SessionImpl.java:1597)
        at org.hibernate.impl.CriteriaImpl.list(CriteriaImpl.java:306)
        at edu.asd.myproj.hibernate.adapter.CriteriaAdapter.list(CriteriaAdapter.java:380)
        at edu.asd.myproj.DaoHibernateImpl.findByCriteria(DaoHibernateImpl.java:778)
        at edu.asd.myproj.DaoHibernateImpl.findByCriteria(DaoHibernateImpl.java:765)
        at edu.asd.myproj.DaoHibernateImpl.findByProperty(DaoHibernateImpl.java:361)
        at edu.asd.myproj.ProfilesDaoImpl.count(ProfilesDaoImpl.java:81)
        at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
        at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
        at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
        at java.lang.reflect.Method.invoke(Method.java:597)
        at org.springframework.aop.support.AopUtils.invokeJoinpointUsingReflection(AopUtils.java:307)
        at org.springframework.aop.framework.ReflectiveMethodInvocation.invokeJoinpoint(ReflectiveMethodInvocation.java:182)
        at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:149)
        at org.springframework.transaction.interceptor.TransactionInterceptor.invoke(TransactionInterceptor.java:106)
        at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:171)
        at org.springframework.aop.framework.JdkDynamicAopProxy.invoke(JdkDynamicAopProxy.java:204)
        at $Proxy27.count(Unknown Source)
        at edu.asd.myproj.ResourceProfileLoaderNew.loadProfiles(ResourceProfileLoaderNew.java:66)
        at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
        at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
        at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
        at java.lang.reflect.Method.invoke(Method.java:597)
        at org.springframework.beans.factory.annotation.InitDestroyAnnotationBeanPostProcessor$LifecycleElement.invoke(InitDestroyAnnotationBeanPostProcessor.java:297)
        at org.springframework.beans.factory.annotation.InitDestroyAnnotationBeanPostProcessor$LifecycleMetadata.invokeInitMethods(InitDestroyAnnotationBeanPostProcessor.java:250)
        at org.springframework.beans.factory.annotation.InitDestroyAnnotationBeanPostProcessor.postProcessBeforeInitialization(InitDestroyAnnotationBeanPostProcessor.java:144)
        ... 50 more
    Caused by: com.mysql.jdbc.exceptions.jdbc4.CommunicationsException: The last packet successfully received from the server was44323 seconds ago.The last packet sent successfully to the server was 44323 seconds ago, which  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:39)
        at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:27)
        at java.lang.reflect.Constructor.newInstance(Constructor.java:513)
        at com.mysql.jdbc.Util.handleNewInstance(Util.java:406)
        at com.mysql.jdbc.SQLError.createCommunicationsException(SQLError.java:1074)
        at com.mysql.jdbc.MysqlIO.send(MysqlIO.java:3246)
        at com.mysql.jdbc.MysqlIO.sendCommand(MysqlIO.java:1917)
        at com.mysql.jdbc.MysqlIO.sqlQueryDirect(MysqlIO.java:2060)
        at com.mysql.jdbc.ConnectionImpl.execSQL(ConnectionImpl.java:2542)
        at com.mysql.jdbc.PreparedStatement.executeInternal(PreparedStatement.java:1734)
        at com.mysql.jdbc.PreparedStatement.executeQuery(PreparedStatement.java:1885)
        at org.apache.commons.dbcp.DelegatingPreparedStatement.executeQuery(DelegatingPreparedStatement.java:93)
        at org.hibernate.jdbc.AbstractBatcher.getResultSet(AbstractBatcher.java:208)
        at org.hibernate.loader.Loader.getResultSet(Loader.java:1812)
        at org.hibernate.loader.Loader.doQuery(Loader.java:697)
        at org.hibernate.loader.Loader.doQueryAndInitializeNonLazyCollections(Loader.java:259)
        at org.hibernate.loader.Loader.doList(Loader.java:2232)
        ... 79 more
    Caused by: java.net.SocketException: Broken pipe
        at java.net.SocketOutputStream.socketWrite0(Native Method)
        at java.net.SocketOutputStream.socketWrite(SocketOutputStream.java:92)
        at java.net.SocketOutputStream.write(SocketOutputStream.java:136)
        at java.io.BufferedOutputStream.flushBuffer(BufferedOutputStream.java:65)
        at java.io.BufferedOutputStream.flush(BufferedOutputStream.java:123)
        at com.mysql.jdbc.MysqlIO.send(MysqlIO.java:3227)
        ... 90 more

这是我的hibernate.properties文件

# Turn on for SQL debugging
hibernate.show_sql=true

# Generate schema?
hibernate.hbm2ddl.auto=validate

#============================================================
# C3P0 connection pool configuration
#============================================================
#changed to default values 
c3p0.acquireIncrement=hibernate.c3p0.acquire_increment
c3p0.idleConnectionTestPeriod=hibernate.c3p0.idle_test_period
c3p0.initialPoolSize=10
c3p0.maxIdleTime=hibernate.c3p0.timeout
c3p0.maxPoolSize=hibernate.c3p0.max_size
c3p0.maxStatements=hibernate.c3p0.max_statements
c3p0.minPoolSize=hibernate.c3p0.min_size   
c3p0.testConnectionsOnCheckout=hibernate.c3p0.validate

错误会随机出现一次，并且需要很长时间才能重新出现，一旦刷新就会消失。

Answer 1

请发送完整的异常堆栈跟踪，以进一步了解读者。

通常在DB Connection陈旧时发生此异常。

过时的意思是 ：服务器终止了连接，但池仍然认为该连接处于活动状态。 您需要在连接中配置连接测试。 对于C3P0这种方法，您必须使用以下配置：

c3p0.testConnectionOnCheckin = true
testConnectionOnCheckout= true

对于更多检查，请增加结帐超时，如下所示：

c3p0.checkoutTimeout = 0

并在C3P0测试另一个测试选项，例如：

• connectionTesterClassName
• idleConnectionTestPeriod
• automaticTestTable
• preferredTestQuery

测试的另一种方法是编写示例代码并通过JDBC pure代码连接到数据库（通过DriverManager和Connection等）。