网站传到服务器上后，网站运行正常，但是过一段时间就会出现could not execute query不能执行查询，也就是说不能连接数据库了，但为什么重启一下服务器网站就又用正常运行了
详细错误：
org.hibernate.exception.JDBCConnectionException: could not execute query
org.hibernate.exception.SQLStateConverter.convert(SQLStateConverter.java:74)
org.hibernate.exception.JDBCExceptionHelper.convert(JDBCExceptionHelper.java:43)
org.hibernate.loader.Loader.doList(Loader.java:2148)
org.hibernate.loader.Loader.listIgnoreQueryCache(Loader.java:2029)
org.hibernate.loader.Loader.list(Loader.java:2024)
org.hibernate.loader.hql.QueryLoader.list(QueryLoader.java:375)
org.hibernate.hql.ast.QueryTranslatorImpl.list(QueryTranslatorImpl.java:308)
org.hibernate.engine.query.HQLQueryPlan.performList(HQLQueryPlan.java:153)
org.hibernate.impl.SessionImpl.list(SessionImpl.java:1106)
org.hibernate.impl.QueryImpl.list(QueryImpl.java:79)
myDAO.MyComStateDAO.findState(MyComStateDAO.java:17)
org.apache.jsp.index_jsp._jspService(index_jsp.java:65)
org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:98)
javax.servlet.http.HttpServlet.service(HttpServlet.java:803)
org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:328)
org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:315)
org.apache.jasper.servlet.JspServlet.service(JspServlet.java:265)
javax.servlet.http.HttpServlet.service(HttpServlet.java:803)
root cause com.mysql.jdbc.exceptions.jdbc4.MySQLNonTransientConnectionException: No operations allowed after connection closed.Connection was implicitly closed due to underlying exception/error:
** BEGIN NESTED EXCEPTION ** com.mysql.jdbc.exceptions.jdbc4.CommunicationsException
MESSAGE: Communications link failure Last packet sent to the server was 0 ms ago. STACKTRACE: com.mysql.jdbc.exceptions.jdbc4.CommunicationsException: Communications link failure Last packet sent to the server was 0 ms ago.
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:3134)
at com.mysql.jdbc.MysqlIO.sendCommand(MysqlIO.java:1818)
at com.mysql.jdbc.MysqlIO.sqlQueryDirect(MysqlIO.java:1961)
at com.mysql.jdbc.ConnectionImpl.execSQL(ConnectionImpl.java:2543)
at com.mysql.jdbc.PreparedStatement.executeInternal(PreparedStatement.java:1737)
at com.mysql.jdbc.PreparedStatement.executeQuery(PreparedStatement.java:1888)
at org.hibernate.jdbc.AbstractBatcher.getResultSet(AbstractBatcher.java:139)
at org.hibernate.loader.Loader.getResultSet(Loader.java:1669)
at org.hibernate.loader.Loader.doQuery(Loader.java:662)
at org.hibernate.loader.Loader.doQueryAndInitializeNonLazyCollections(Loader.java:224)
at org.hibernate.loader.Loader.doList(Loader.java:2145)
at org.hibernate.loader.Loader.listIgnoreQueryCache(Loader.java:2029)
at org.hibernate.loader.Loader.list(Loader.java:2024)
at org.hibernate.loader.hql.QueryLoader.list(QueryLoader.java:375)
at org.hibernate.hql.ast.QueryTranslatorImpl.list(QueryTranslatorImpl.java:308)
at org.hibernate.engine.query.HQLQueryPlan.performList(HQLQueryPlan.java:153)
at org.hibernate.impl.SessionImpl.list(SessionImpl.java:1106)
at org.hibernate.impl.QueryImpl.list(QueryImpl.java:79)
at myDAO.MyComStateDAO.findState(MyComStateDAO.java:17)
at org.apache.jsp.index_jsp._jspService(index_jsp.java:65)
at org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:98)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:803)
at org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:328)
at org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:315)
at org.apache.jasper.servlet.JspServlet.service(JspServlet.java:265)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:803)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:269)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:188)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:210)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:174)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:127)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:117)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:108)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:151)
at org.apache.jk.server.JkCoyoteHandler.invoke(JkCoyoteHandler.java:200)
at org.apache.jk.common.HandlerRequest.invoke(HandlerRequest.java:283)
at org.apache.jk.common.ChannelSocket.invoke(ChannelSocket.java:773)
at org.apache.jk.common.ChannelSocket.processConnection(ChannelSocket.java:703)
at org.apache.jk.common.ChannelSocket$SocketConnection.runIt(ChannelSocket.java:895)
at org.apache.tomcat.util.threads.ThreadPool$ControlRunnable.run(ThreadPool.java:685)
at java.lang.Thread.run(Thread.java:619)
Caused by: java.net.SocketException: Software caused connection abort: socket write error
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:3119)
... 40 more
** END NESTED EXCEPTION **
sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:39)
sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:27)
java.lang.reflect.Constructor.newInstance(Constructor.java:513)
com.mysql.jdbc.Util.handleNewInstance(Util.java:406)
com.mysql.jdbc.Util.getInstance(Util.java:381)
com.mysql.jdbc.SQLError.createSQLException(SQLError.java:985)
com.mysql.jdbc.SQLError.createSQLException(SQLError.java:957)
com.mysql.jdbc.SQLError.createSQLException(SQLError.java:927)
com.mysql.jdbc.ConnectionImpl.checkClosed(ConnectionImpl.java:1113)
com.mysql.jdbc.ConnectionImpl.prepareStatement(ConnectionImpl.java:4038)
com.mysql.jdbc.ConnectionImpl.prepareStatement(ConnectionImpl.java:4004)
org.hibernate.jdbc.AbstractBatcher.getPreparedStatement(AbstractBatcher.java:442)
org.hibernate.jdbc.AbstractBatcher.getPreparedStatement(AbstractBatcher.java:368)
org.hibernate.jdbc.AbstractBatcher.prepareQueryStatement(AbstractBatcher.java:105)
org.hibernate.loader.Loader.prepareQueryStatement(Loader.java:1561)
org.hibernate.loader.Loader.doQuery(Loader.java:661)
org.hibernate.loader.Loader.doQueryAndInitializeNonLazyCollections(Loader.java:224)
org.hibernate.loader.Loader.doList(Loader.java:2145)
org.hibernate.loader.Loader.listIgnoreQueryCache(Loader.java:2029)
org.hibernate.loader.Loader.list(Loader.java:2024)
org.hibernate.loader.hql.QueryLoader.list(QueryLoader.java:375)
org.hibernate.hql.ast.QueryTranslatorImpl.list(QueryTranslatorImpl.java:308)
org.hibernate.engine.query.HQLQueryPlan.performList(HQLQueryPlan.java:153)
org.hibernate.impl.SessionImpl.list(SessionImpl.java:1106)
org.hibernate.impl.QueryImpl.list(QueryImpl.java:79)
myDAO.MyComStateDAO.findState(MyComStateDAO.java:17)
org.apache.jsp.index_jsp._jspService(index_jsp.java:65)
org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:98)
javax.servlet.http.HttpServlet.service(HttpServlet.java:803)
org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:328)
org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:315)
org.apache.jasper.servlet.JspServlet.service(JspServlet.java:265)
javax.servlet.http.HttpServlet.service(HttpServlet.java:803)
note The full stack trace of the root cause is available in the Apache Tomcat/5.5.23 logs.
详细错误：
org.hibernate.exception.JDBCConnectionException: could not execute query
org.hibernate.exception.SQLStateConverter.convert(SQLStateConverter.java:74)
org.hibernate.exception.JDBCExceptionHelper.convert(JDBCExceptionHelper.java:43)
org.hibernate.loader.Loader.doList(Loader.java:2148)
org.hibernate.loader.Loader.listIgnoreQueryCache(Loader.java:2029)
org.hibernate.loader.Loader.list(Loader.java:2024)
org.hibernate.loader.hql.QueryLoader.list(QueryLoader.java:375)
org.hibernate.hql.ast.QueryTranslatorImpl.list(QueryTranslatorImpl.java:308)
org.hibernate.engine.query.HQLQueryPlan.performList(HQLQueryPlan.java:153)
org.hibernate.impl.SessionImpl.list(SessionImpl.java:1106)
org.hibernate.impl.QueryImpl.list(QueryImpl.java:79)
myDAO.MyComStateDAO.findState(MyComStateDAO.java:17)
org.apache.jsp.index_jsp._jspService(index_jsp.java:65)
org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:98)
javax.servlet.http.HttpServlet.service(HttpServlet.java:803)
org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:328)
org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:315)
org.apache.jasper.servlet.JspServlet.service(JspServlet.java:265)
javax.servlet.http.HttpServlet.service(HttpServlet.java:803)
root cause com.mysql.jdbc.exceptions.jdbc4.MySQLNonTransientConnectionException: No operations allowed after connection closed.Connection was implicitly closed due to underlying exception/error:
** BEGIN NESTED EXCEPTION ** com.mysql.jdbc.exceptions.jdbc4.CommunicationsException
MESSAGE: Communications link failure Last packet sent to the server was 0 ms ago. STACKTRACE: com.mysql.jdbc.exceptions.jdbc4.CommunicationsException: Communications link failure Last packet sent to the server was 0 ms ago.
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:3134)
at com.mysql.jdbc.MysqlIO.sendCommand(MysqlIO.java:1818)
at com.mysql.jdbc.MysqlIO.sqlQueryDirect(MysqlIO.java:1961)
at com.mysql.jdbc.ConnectionImpl.execSQL(ConnectionImpl.java:2543)
at com.mysql.jdbc.PreparedStatement.executeInternal(PreparedStatement.java:1737)
at com.mysql.jdbc.PreparedStatement.executeQuery(PreparedStatement.java:1888)
at org.hibernate.jdbc.AbstractBatcher.getResultSet(AbstractBatcher.java:139)
at org.hibernate.loader.Loader.getResultSet(Loader.java:1669)
at org.hibernate.loader.Loader.doQuery(Loader.java:662)
at org.hibernate.loader.Loader.doQueryAndInitializeNonLazyCollections(Loader.java:224)
at org.hibernate.loader.Loader.doList(Loader.java:2145)
at org.hibernate.loader.Loader.listIgnoreQueryCache(Loader.java:2029)
at org.hibernate.loader.Loader.list(Loader.java:2024)
at org.hibernate.loader.hql.QueryLoader.list(QueryLoader.java:375)
at org.hibernate.hql.ast.QueryTranslatorImpl.list(QueryTranslatorImpl.java:308)
at org.hibernate.engine.query.HQLQueryPlan.performList(HQLQueryPlan.java:153)
at org.hibernate.impl.SessionImpl.list(SessionImpl.java:1106)
at org.hibernate.impl.QueryImpl.list(QueryImpl.java:79)
at myDAO.MyComStateDAO.findState(MyComStateDAO.java:17)
at org.apache.jsp.index_jsp._jspService(index_jsp.java:65)
at org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:98)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:803)
at org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:328)
at org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:315)
at org.apache.jasper.servlet.JspServlet.service(JspServlet.java:265)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:803)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:269)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:188)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:210)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:174)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:127)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:117)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:108)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:151)
at org.apache.jk.server.JkCoyoteHandler.invoke(JkCoyoteHandler.java:200)
at org.apache.jk.common.HandlerRequest.invoke(HandlerRequest.java:283)
at org.apache.jk.common.ChannelSocket.invoke(ChannelSocket.java:773)
at org.apache.jk.common.ChannelSocket.processConnection(ChannelSocket.java:703)
at org.apache.jk.common.ChannelSocket$SocketConnection.runIt(ChannelSocket.java:895)
at org.apache.tomcat.util.threads.ThreadPool$ControlRunnable.run(ThreadPool.java:685)
at java.lang.Thread.run(Thread.java:619)
Caused by: java.net.SocketException: Software caused connection abort: socket write error
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:3119)
... 40 more
** END NESTED EXCEPTION **
sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:39)
sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:27)
java.lang.reflect.Constructor.newInstance(Constructor.java:513)
com.mysql.jdbc.Util.handleNewInstance(Util.java:406)
com.mysql.jdbc.Util.getInstance(Util.java:381)
com.mysql.jdbc.SQLError.createSQLException(SQLError.java:985)
com.mysql.jdbc.SQLError.createSQLException(SQLError.java:957)
com.mysql.jdbc.SQLError.createSQLException(SQLError.java:927)
com.mysql.jdbc.ConnectionImpl.checkClosed(ConnectionImpl.java:1113)
com.mysql.jdbc.ConnectionImpl.prepareStatement(ConnectionImpl.java:4038)
com.mysql.jdbc.ConnectionImpl.prepareStatement(ConnectionImpl.java:4004)
org.hibernate.jdbc.AbstractBatcher.getPreparedStatement(AbstractBatcher.java:442)
org.hibernate.jdbc.AbstractBatcher.getPreparedStatement(AbstractBatcher.java:368)
org.hibernate.jdbc.AbstractBatcher.prepareQueryStatement(AbstractBatcher.java:105)
org.hibernate.loader.Loader.prepareQueryStatement(Loader.java:1561)
org.hibernate.loader.Loader.doQuery(Loader.java:661)
org.hibernate.loader.Loader.doQueryAndInitializeNonLazyCollections(Loader.java:224)
org.hibernate.loader.Loader.doList(Loader.java:2145)
org.hibernate.loader.Loader.listIgnoreQueryCache(Loader.java:2029)
org.hibernate.loader.Loader.list(Loader.java:2024)
org.hibernate.loader.hql.QueryLoader.list(QueryLoader.java:375)
org.hibernate.hql.ast.QueryTranslatorImpl.list(QueryTranslatorImpl.java:308)
org.hibernate.engine.query.HQLQueryPlan.performList(HQLQueryPlan.java:153)
org.hibernate.impl.SessionImpl.list(SessionImpl.java:1106)
org.hibernate.impl.QueryImpl.list(QueryImpl.java:79)
myDAO.MyComStateDAO.findState(MyComStateDAO.java:17)
org.apache.jsp.index_jsp._jspService(index_jsp.java:65)
org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:98)
javax.servlet.http.HttpServlet.service(HttpServlet.java:803)
org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:328)
org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:315)
org.apache.jasper.servlet.JspServlet.service(JspServlet.java:265)
javax.servlet.http.HttpServlet.service(HttpServlet.java:803)
note The full stack trace of the root cause is available in the Apache Tomcat/5.5.23 logs.
出现错误的原因：
Mysql服务器默认的“wait_timeout”是8小时，也就是说一个connection空闲超过8个小时，Mysql将自动断开该 connection。
解决方法：
建一个数据库连接池就可以解决此问题。