无法实现文件的上传，老报错？？求大神帮帮忙解决一下，包和配置文件都配置好了

package servlet;import java.io.IOException;
import java.io.PrintWriter;import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;import javax.servlet.ServletConfig;import com.jspsmart.upload.File;
import com.jspsmart.upload.Request;
import com.jspsmart.upload.SmartUpload;
import com.jspsmart.upload.SmartUploadException;
import dao.NewsDao;
import dao.impl.NewsDaoimpl;import bean.News;public class AddServlet extends HttpServlet {


protected void service(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException { //PrintWriter out = response.getWriter(); //out.println("Hello");
SmartUpload su=new SmartUpload();

Request req  = null;
try{
su.initialize(this.getServletConfig(),request,response);
su.setAllowedFilesList("jpg,gif,doc");
su.upload();
File file=su.getFiles().getFile(0);
String filepath="upload//";
filepath+=file.getFieldName();
file.saveAs(filepath,SmartUpload.SAVE_VIRTUAL ); req  = su.getRequest();
}catch(Exception e){
System.out.println(e.getMessage());
}
//request.setCharacterEncoding("utf-8");
News news=new News();
NewsDao nDao=new NewsDaoimpl();
Integer Tnid=Integer.parseInt(req.getParameter("ntid"));
String ntitle=req.getParameter("ntitle");
String nauthor=req.getParameter("nauthor");
String nsummary=req.getParameter("nsummary");
String ncontent=req.getParameter("ncontent");
String path=req.getParameter("file");
news.setNtid(Tnid);
news.setNtitle(ntitle);
news.setNauthor(nauthor);
news.setNsummary(nsummary);
news.setNcontent(ncontent);
news.setNpicpath(path);
try {
if(nDao.addNews(news)>0){
System.out.println("<Script> alert('添加成功！');location='../admin.jsp' </Script>");
}else{
response.sendRedirect("../news_add.jsp");
}
} catch (Exception e) { e.printStackTrace();
}
}
}
控制台输出的报错提示：
2012-5-28 17:50:57 org.apache.catalina.core.AprLifecycleListener init
信息: The Apache Tomcat Native library which allows optimal performance in production environments was not found on the java.library.path: D:\Users\MRqiang\AppData\Local\Genuitec\Common\binary\com.sun.java.jdk.win32.x86_1.6.0.013\bin;D:\Users\MRqiang\AppData\Local\Genuitec\Common\plugins\com.genuitec.eclipse.easie.tomcat.myeclipse_8.6.0.me201007231647\tomcat\bin
2012-5-28 17:50:57 org.apache.coyote.http11.Http11Protocol init
信息: Initializing Coyote HTTP/1.1 on http-8080
2012-5-28 17:50:57 org.apache.catalina.startup.Catalina load
信息: Initialization processed in 1962 ms
2012-5-28 17:50:57 org.apache.catalina.core.StandardService start
信息: Starting service Catalina
2012-5-28 17:50:57 org.apache.catalina.core.StandardEngine start
信息: Starting Servlet Engine: Apache Tomcat/6.0.13
2012-5-28 17:51:00 com.sun.faces.config.ConfigureListener$WebXmlProcessor scanForFacesServlet
警告: Unable to process deployment descriptor for context 'null'
2012-5-28 17:51:00 com.sun.faces.config.ConfigureListener contextInitialized
信息: Initializing Sun's JavaServer Faces implementation (1.2_04-b07-FCS) for context '/Demo'
2012-5-28 17:51:02 org.apache.coyote.http11.Http11Protocol start
信息: Starting Coyote HTTP/1.1 on http-8080
2012-5-28 17:51:02 org.apache.jk.common.ChannelSocket init
信息: JK: ajp13 listening on /0.0.0.0:8009
2012-5-28 17:51:02 org.apache.jk.server.JkMain start
信息: Jk running ID=0 time=0/234  config=null
2012-5-28 17:51:02 org.apache.catalina.startup.Catalina start
信息: Server startup in 5112 ms
Files' name is invalid or does not exist (1205).
2012-5-28 18:00:58 org.apache.catalina.core.StandardWrapperValve invoke
严重: Servlet.service() for servlet AddServlet threw exception
java.lang.NullPointerException
at servlet.AddServlet.service(AddServlet.java:58)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:803)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:290)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:230)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:175)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:128)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:104)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:261)
at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:844)
at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:581)
at org.apache.tomcat.util.net.JIoEndpoint$Worker.run(JIoEndpoint.java:447)
at java.lang.Thread.run(Thread.java:619)