The server encountered an internal error () that prevented it from fulfillin

Question

连接成功
java.lang.NullPointerException
at com.blog.toolsBean.JDBConnection.getStm(JDBConnection.java:40)
at com.blog.toolsBean.JDBConnection.executeQuery(JDBConnection.java:71)
at com.blog.dao.ConsumerDao.getConsumerForm(ConsumerDao.java:89)
at com.blog.servlet.ConsumerServlet.registerConsumer(ConsumerServlet.java:76)
at com.blog.servlet.ConsumerServlet.doPost(ConsumerServlet.java:21)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:710)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:803)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:290)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:230)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:175)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:128)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:104)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:261)
at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:844)
at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:581)
at org.apache.tomcat.util.net.JIoEndpoint$Worker.run(JIoEndpoint.java:447)
at java.lang.Thread.run(Unknown Source)
2010-4-29 18:05:14 org.apache.catalina.core.StandardWrapperValve invoke
严重: Servlet.service() for servlet ConsumerServlet threw exception
java.lang.NullPointerException
at com.blog.dao.ConsumerDao.getConsumerForm(ConsumerDao.java:90)
at com.blog.servlet.ConsumerServlet.registerConsumer(ConsumerServlet.java:76)
at com.blog.servlet.ConsumerServlet.doPost(ConsumerServlet.java:21)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:710)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:803)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:290)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:230)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:175)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:128)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:104)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:261)
at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:844)
at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:581)
at org.apache.tomcat.util.net.JIoEndpoint$Worker.run(JIoEndpoint.java:447)
at java.lang.Thread.run(Unknown Source)

Answer 1

连接成功
java.lang.NullPointerException
at com.blog.toolsBean.JDBConnection.getStm(JDBConnection.java:40)这里的错。你的连接成功估计是个假相，连接根本就不成功，要不怎么取不到statement呢？好好看下代码。看下你的jdbc url、user、pwd、端口等是否都正确，

Answer 2

NullPointerException
都告诉你了嘛~去找吧~
LIST，SET,STRING之类的，慢慢找~单步跟踪吧

Answer 3

at com.blog.dao.ConsumerDao.getConsumerForm(ConsumerDao.java:90)
at com.blog.servlet.ConsumerServlet.registerConsumer(ConsumerServlet.java:76)
at com.blog.servlet.ConsumerServlet.doPost(ConsumerServlet.java:21)把这三行错误中设计到的对象在控制台输出，确定下是不是对象的值为空。为空连接出错.