分享一個JDBC查數據庫出現的一個問題

問題詳情，緊急需求臨時搞了一個JDBC查Hive的引擎，根據獲取的ResultSet在內存做計算，需要把ResultSet保留在內存一段時間，但是在後續對ResultSet的處理中出現了錯誤，錯誤詳情：

java.sql.SQLException: Error retrieving next row
	at org.apache.hive.jdbc.HiveQueryResultSet.next(HiveQueryResultSet.java:392)
	....
	at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:967)
	at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:901)
	at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:970)
	at org.springframework.web.servlet.FrameworkServlet.doPost(FrameworkServlet.java:872)
	at javax.servlet.http.HttpServlet.service(HttpServlet.java:647)
	at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:846)
	at javax.servlet.http.HttpServlet.service(HttpServlet.java:728)
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:305)
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210)
	at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:51)
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:243)
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210)
	at com.wormpex.cvs.usercenter.api.filter.CasLoginFilter.doFilter(CasLoginFilter.java:254)
	at org.springframework.web.filter.DelegatingFilterProxy.invokeDelegate(DelegatingFilterProxy.java:347)
	at org.springframework.web.filter.DelegatingFilterProxy.doFilter(DelegatingFilterProxy.java:263)
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:243)
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210)
	at org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:197)
	at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:243)
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210)
	at com.wormpex.common.web.trace.http.WTraceFilterWrapper.doFilter(WTraceFilterWrapper.java:112)
	at com.wormpex.common.web.service.ServiceWatcher.doFilter(ServiceWatcher.java:124)
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:243)
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210)
	at org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:197)
	at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:243)
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210)
	at org.apache.logging.log4j.web.Log4jServletFilter.doFilter(Log4jServletFilter.java:71)
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:243)
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210)
	at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:222)
	at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:123)
	at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
	at java.lang.Thread.run(Thread.java:745)
Caused by: org.apache.thrift.transport.TTransportException: SASL authentication not complete
	at org.apache.thrift.transport.TSaslTransport.write(TSaslTransport.java:474)
	at org.apache.thrift.transport.TSaslClientTransport.write(TSaslClientTransport.java:37)
	at org.apache.thrift.protocol.TBinaryProtocol.writeI32(TBinaryProtocol.java:178)
	at org.apache.thrift.protocol.TBinaryProtocol.writeMessageBegin(TBinaryProtocol.java:106)
	at org.apache.thrift.TServiceClient.sendBase(TServiceClient.java:70)
	at org.apache.thrift.TServiceClient.sendBase(TServiceClient.java:62)
	at org.apache.hive.service.rpc.thrift.TCLIService$Client.send_FetchResults(TCLIService.java:553)
	at org.apache.hive.service.rpc.thrift.TCLIService$Client.FetchResults(TCLIService.java:545)
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
	at java.lang.reflect.Method.invoke(Method.java:498)
	at org.apache.hive.jdbc.HiveConnection$SynchronizedHandler.invoke(HiveConnection.java:1524)
	at com.sun.proxy.$Proxy79.FetchResults(Unknown Source)
	at org.apache.hive.jdbc.HiveQueryResultSet.next(HiveQueryResultSet.java:373)
	... 61 common frames omitted

代碼片段：

try {
    ResultSet resultSet = ...
    //處理resultSet
    return resultSet;//直接返回Result
} catch (Exception e) {
    //
}
finally {
    connection.close()
}

原因分析：

Connection被提前關閉，如果說是在獲取到ResultSet後沒有做任何處理就吧連接關閉掉，後續再處理ResultSet的時候就會報錯，因爲這個時候數據實際上還沒有取到內存中，在遍歷RsultSet的時候才實際取數據，所以此時如果連接關閉掉了，肯定就取不到數據了。

注意點：

如果說需要在方法外面去使用ResultSet，那麼就不能在使用ResultSet之前去關閉Connection(關閉ResultSet)