如何解决在jsp页面上导入.xls文件报错问题

在jsp页面上导入.xls文件，报错：
java.io.IOException: Posted content type isn't multipart/form-data
at com.oreilly.servlet.multipart.MultipartParser.<init>(MultipartParser.java:166)
at com.oreilly.servlet.MultipartRequest.<init>(MultipartRequest.java:222)
at org.apache.jsp.dxt.sms.multi_005fsender.upload_jsp._jspService(upload_jsp.java:406)
at org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:70)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
at org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:386)
at org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:313)
at org.apache.jasper.servlet.JspServlet.service(JspServlet.java:260)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:290)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at sdcncsi.ict.security.AclFilter.doFilter(AclFilter.java:78)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at sdcncsi.ict.web.RequestFilter.doFilter(RequestFilter.java:108)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235)
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:76)
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:233)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:191)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:127)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:102)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:298)
at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:859)
at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:588)
at org.apache.tomcat.util.net.JIoEndpoint$Worker.run(JIoEndpoint.java:489)
at java.lang.Thread.run(Thread.java:619)
不知道是什么原因？应该怎样来解决呢？
解决这个错误，需要在form表单里面加上加enctype=”multipart/form-data” 这个属性，不过表单请求传到另一个jsp或servlet里时，是不能用request.getParameter()来获取到各个表单元素的值的，如下：

 
 
 
 
 
 
 
 
 
 
 
"); 
out.println("alert('错误：文件类型错误！');"); 
out.println(""); 
return; 
} 
//判断文件夹是否存在，不存在创建 
String file_path = SysPara.getValue("dxt_sms_multi_sender_file_path"); 
file_path=file_path.replace("\","//"); 
if (!fileFuns.getFileIsExists(file_path)) { 
fileFuns.Createdir(file_path); 
} 
String file_size = SysPara.getValue("dxt_sms_multi_sender_file_size"); 
//文件上传后，保存在saveDirectory 
saveDirectory = file_path; 
RandomFileRenamePolicy rfrp = new RandomFileRenamePolicy(); 
MultipartRequest multi = null; 
System.out.println("saveDirectory" saveDirectory); 
System.out.println("file_size" file_size); 
multi = new MultipartRequest(request, saveDirectory, Integer 
.parseInt(file_size), "utf-8", rfrp); 
System.out.println("222" multi); 
//输出反馈信息 
Enumeration files = multi.getFileNames(); 
while (files.hasMoreElements()) { 
String name = (String) files.nextElement(); 
File f = multi.getFile(name); 
if (f != null) { 
String fileName = multi.getFilesystemName(name); 
saveDirectory =fileName; 
} 
} 
} catch (Exception eu) { 
res="false"; 
eu.printStackTrace(); 
out.println(""); 
} 
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