ResultSet 结果集问题

Question

String sql="select * from mainwant";
ResultSet rs=dbBean.executeQuery(sql);
       if(rs.next())
         {
out.print("next ok!");
}
这样的话就有NullPointerException错误
补充：在自己机器上没错，放服务器上就不行

Answer 1

要看看是哪一行报的空指针
try{
ResultSet rs=dbBean.executeQuery(sql);
       if(rs.next())
         {
out.print("next ok!");
}
}
catch(Exception ex)
{     
 ex.printStackTrace();
}估计是dbBean为空了，放到服务器上后，你的数据库连接没弄好

Answer 2

还是一样的问题
java.lang.NullPointerException
org.apache.jsp.user.demo_jsp._jspService(demo_jsp.java:73)
org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:94)
javax.servlet.http.HttpServlet.service(HttpServlet.java:802)
org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:324)
org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:292)
org.apache.jasper.servlet.JspServlet.service(JspServlet.java:236)
javax.servlet.http.HttpServlet.service(HttpServlet.java:802)
note The full stack trace of the root cause is available in the Apache Tomcat/5.0.28 logs.Bean我都是一样的，我别的页面都没问题，就是这个表。。

Answer 3

为什么把users表换成Maintain结果rs就为空了
String sql="select * from mainwant";
别的页面都没问题
----------------------------------表到底是Maintain还是mainwant啊

Answer 4

是mainwant，表名没错的，这是什么错误呀

Answer 5

找到原因了，有谁知道 这原因java.sql.SQLException: [Microsoft][SQLServer JDBC Driver]Unhandled data type: TD
S_INT8
        at com.microsoft.jdbc.base.BaseExceptions.getException(Unknown Source)
        at com.microsoft.jdbc.sqlserver.tds.TDSRequest.processColMetaData(Unknow
n Source)
        at com.microsoft.jdbc.sqlserver.tds.TDSExecuteRequest.processReplyToken(
Unknown Source)
        at com.microsoft.jdbc.sqlserver.tds.TDSRequest.processReply(Unknown Sour
ce)
        at com.microsoft.jdbc.sqlserver.SQLServerImplStatement.getNextResultType
(Unknown Source)
        at com.microsoft.jdbc.base.BaseStatement.commonExecute(Unknown Source)
        at com.microsoft.jdbc.base.BaseStatement.executeQueryInternal(Unknown So
urce)
        at com.microsoft.jdbc.base.BaseStatement.executeQuery(Unknown Source)
        at dbconn.Top101DbConn.executeQuery(top101dbconn.java:43)
        at org.apache.jsp.user.MyAnswer_jsp._jspService(MyAnswer_jsp.java:108)
        at org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:94)
        at javax.servlet.http.HttpServlet.service(HttpServlet.java:802)
        at org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper
.java:324)
        at org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:2
92)
        at org.apache.jasper.servlet.JspServlet.service(JspServlet.java:236)
        at javax.servlet.http.HttpServlet.service(HttpServlet.java:802)
        at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(Appl
icationFilterChain.java:237)
        at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationF
ilterChain.java:157)
        at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperV
alve.java:214)
        at org.apache.catalina.core.StandardValveContext.invokeNext(StandardValv
eContext.java:104)
        at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.jav
a:520)
        at org.apache.catalina.core.StandardContextValve.invokeInternal(Standard
ContextValve.java:198)
        at org.apache.catalina.core.StandardContextValve.invoke(StandardContextV
alve.java:152)
        at org.apache.catalina.core.StandardValveContext.invokeNext(StandardValv
eContext.java:104)
        at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.jav
a:520)
        at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.j
ava:137)
        at org.apache.catalina.core.StandardValveContext.invokeNext(StandardValv
eContext.java:104)
        at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.j
ava:118)
        at org.apache.catalina.core.StandardValveContext.invokeNext(StandardValv
eContext.java:102)
        at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.jav
a:520)
        at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineVal
ve.java:109)
        at org.apache.catalina.core.StandardValveContext.invokeNext(StandardValv
eContext.java:104)
        at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.jav
a:520)
        at org.apache.catalina.core.ContainerBase.invoke(ContainerBase.java:929)        at org.apache.coyote.tomcat5.CoyoteAdapter.service(CoyoteAdapter.java:16
0)
        at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java
:799)
        at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.proce
ssConnection(Http11Protocol.java:705)
        at org.apache.tomcat.util.net.TcpWorkerThread.runIt(PoolTcpEndpoint.java
:577)
        at org.apache.tomcat.util.threads.ThreadPool$ControlRunnable.run(ThreadP
ool.java:683)
        at java.lang.Thread.run(Thread.java:534)

Answer 6

java.sql.SQLException: [Microsoft][SQLServer JDBC Driver]Unhandled data type: TD
S_INT8我把表里面字段为bigint的改为int就没事了      有别的解决方法吗，不改bigint