当访问Web服务时，我会随机收到此错误。很难复制，一旦我刷新它，所有功能都按预期运行。
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
错误是随机出现的一次，它再次出现需要很长时间。它会在刷新后消失。
答案 0 :(得分：4)
请发送完整的异常堆栈跟踪，以便更好地了解读者。
这种异常通常发生在DB Connection陈旧时。
陈旧意味着：连接被服务器杀死，但仍被池认为是活着的。您需要在连接中配置连接测试。对于C3P0中的此方法，您必须使用以下配置：
c3p0.testConnectionOnCheckin = true
testConnectionOnCheckout= true
以及更多检查增加结帐超时如下：
c3p0.checkoutTimeout = 0
并测试C3P0中的其他测试选项，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。（DriverManager和Connection等）