用struts的upload上传文件时出现了异常...请大家帮我看看哪里有问题.

Question

jsp里代码：<html:file property="myPic" size="40" onchange="javascript:PreviewImg(this);"></html:file>form里的代码：private FormFile myPic;      public FormFile getMyPic() {
return myPic;
     }      public void setMyPic(FormFile myPic) {
this.myPic = myPic;
     }action 里代码：FormFile file = humanInfoForm.getMyPic();
              System.out.println(file.getFileName());
      InputStream stream = file.getInputStream();
      String path = this.getServlet().getServletContext().getRealPath("/upload");
      System.out.println(path);
      OutputStream outStream = new FileOutputStream(path + "/"+ file.getFileName());
      int bytesRead = 0;
      byte[] by = new byte[8196];
      while ((bytesRead = stream.read(by, 0, 8192)) != -1) {
      outStream.write(by, 0, bytesRead);
      }
      outStream.close();
      stream.close();
}
      } catch (Exception ex) {
ex.printStackTrace();
System.out.println("exception===================");
      }
报了java.lang.NullPointerException  这个异常..大家帮我看看哪里错了...代码基本是拷的我一个同学的，他的没问题，我的就出这个异常了.

Answer 1

  光是这个java.lang.NullPointerException 是看不出错误的，你把具体控制台打印的错误发上来帮你看一下吧...

Answer 2

java.lang.NullPointerException
at org.hrresource.struts.action.HumanInfoAction.addHuman(HumanInfoAction.java:230)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
at java.lang.reflect.Method.invoke(Unknown Source)
at org.apache.struts.actions.DispatchAction.dispatchMethod(DispatchAction.java:270)
at org.apache.struts.actions.DispatchAction.execute(DispatchAction.java:187)
at org.apache.struts.action.RequestProcessor.processActionPerform(RequestProcessor.java:431)
at org.apache.struts.action.RequestProcessor.process(RequestProcessor.java:236)
at org.apache.struts.action.ActionServlet.process(ActionServlet.java:1196)
at org.apache.struts.action.ActionServlet.doPost(ActionServlet.java:432)
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.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:96)
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:75)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235)
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)-------就这些 file.getFileName（）能打出来

Answer 3

 这是你的addHuman中报的错误，你的struts配置文件是不是配置好了，估计是你的struts中的配置问题，就是相应的action是不是和相应的actionform进行了正确的对应....

Answer 4

应该就是上传那块代码的问题吧？能打出 exception===================  这个来 

Answer 5

String path = this.getServlet().getServletContext().getRealPath("/upload");  这句话报的空指针...