boolean isMultipart = ServletFileUpload.isMultipartContent(request);
 if (isMultipart) {
  // Create a factory for disk-based file items
  org.apache.commons.fileupload.FileItemFactory factory = new DiskFileItemFactory();

  // Create a new file upload handler
  ServletFileUpload upload = new ServletFileUpload(factory);
  // Parse the request
  List /* FileItem */items = upload.parseRequest(request);

  // Process the uploaded items
  Iterator iter = items.iterator();
 
  while (iter.hasNext()) {
   org.apache.commons.fileupload.FileItem item = (org.apache.commons.fileupload.FileItem) iter
     .next();
   if (item.isFormField()) {
    String name = item.getFieldName();
    String value = item.getString("GBK");
    //out.println(name + "=" + value);
    params.put(name.toUpperCase(), value.trim());
   } ......
===============================================================================
使用multipart/form-data上传时，发送的请求和一般的http不一样，需要转化后才能读其他参数。  
   
  如果你用spring,它提供一个MultiRequestResolver，只需要：  
  MultipartHttpServletRequest   multipartRequest   =   (MultipartHttpServletRequest)   request;  
  然后就能正常读取参数：  
  multipartRequest.getParameter("xxx");  
   
  以下是spring的处理方法，必须首先安装commons-fileupload组件：  
   
  public   MultipartHttpServletRequest   resolveMultipart(HttpServletRequest   request)   throws   MultipartException   {  
  DiskFileUpload   fileUpload   =   this.fileUpload;  
  String   enc   =   determineEncoding(request);  
   
  //   use   prototype   FileUpload   instance   if   the   request   specifies  
  //   its   own   encoding   that   does   not   match   the   default   encoding  
  if   (!enc.equals(this.defaultEncoding))   {  
  fileUpload   =   new   DiskFileUpload();  
  fileUpload.setSizeMax(this.fileUpload.getSizeMax());  
  fileUpload.setSizeThreshold(this.fileUpload.getSizeThreshold());  
  fileUpload.setRepositoryPath(this.fileUpload.getRepositoryPath());  
  fileUpload.setHeaderEncoding(enc);  
  }  
   
  try   {  
  List   fileItems   =   fileUpload.parseRequest(request);  
  Map   parameters   =   new   HashMap();  
  Map   multipartFiles   =   new   HashMap();  
  for   (Iterator   it   =   fileItems.iterator();   it.hasNext();)   {  
  FileItem   fileItem   =   (FileItem)   it.next();  
  if   (fileItem.isFormField())   {  
  String   value   =   null;  
  try   {  
  value   =   fileItem.getString(enc);  
  }  
  catch   (UnsupportedEncodingException   ex)   {  
  logger.warn("Could   not   decode   multipart   item   '"   +   fileItem.getFieldName()   +  
          "'   with   encoding   '"   +   enc   +   "':   using   platform   default");  
  value   =   fileItem.getString();  
  }  
  String[]   curParam   =   (String[])   parameters.get(fileItem.getFieldName());  
  if   (curParam   ==   null)   {  
  //   simple   form   field  
  parameters.put(fileItem.getFieldName(),   new   String[]   {   value   });  
  }  
  else   {  
  //   array   of   simple   form   fields  
  String[]   newParam   =   StringUtils.addStringToArray(curParam,   value);  
  parameters.put(fileItem.getFieldName(),   newParam);  
  }  
  }  
  else   {  
  //   multipart   file   field  
  CommonsMultipartFile   file   =   new   CommonsMultipartFile(fileItem);  
  multipartFiles.put(file.getName(),   file);  
  if   (logger.isDebugEnabled())   {  
  logger.debug("Found   multipart   file   ["   +   file.getName()   +   "]   of   size   "   +   file.getSize()   +  
          "   bytes   with   original   filename   ["   +   file.getOriginalFilename()   +   "],   stored   "   +  
          file.getStorageDescription());  
  }  
  }  
  }  
  /*****   注意   parameters   就是普通的text之类的字段的值   *****/  
  return   new   DefaultMultipartHttpServletRequest(request,   multipartFiles,   parameters);  
  }  
  catch   (FileUploadBase.SizeLimitExceededException   ex)   {  
  throw   new   MaxUploadSizeExceededException(this.fileUpload.getSizeMax(),   ex);  
  }  
  catch   (FileUploadException   ex)   {  
  throw   new   MultipartException("Could   not   parse   multipart   request",   ex);  
  }  
  }  
====================================================================================================
<form name="userInfo" method="post" action="first_submit.jsp"  ENCTYPE="multipart/form-data">
表单标签中设置enctype="multipart/form-data"来确保匿名上载文件的正确编码。
如下：
 <tr>
    <td height="30" align="right">上传企业营业执照图片：</td>
    <td><INPUT TYPE="FILE" NAME="uploadfile" SIZE="34"  onChange="checkimage()"></td>
  </tr>
就得加ENCTYPE="multipart/form-data"。
表单中enctype="multipart/form-data"的意思，是设置表单的MIME编码。默认情况，这个编码格式是application/x-www-form-urlencoded，不能用于文件上传；只有使用了multipart/form- data，才能完整的传递文件数据，进行下面的操作.
enctype=\"multipart/form-data\"是上传二进制数据; form里面的input的值以2进制的方式传过去。
form里面的input的值以2进制的方式传过去，所以request就得不到值了。 也就是说加了这段代码,用request就会传递不成功,

取表单值加入数据库时，用到下面的：
 SmartUpload su = new SmartUpload();//新建一个SmartUpload对象
 su.getRequest().getParameterValues();取数组值
 su.getRequest().getParameter( );取单个参数单个值