Servlet获取表单中上传文件流

	private InputStream getFileInputStream(){
		boolean isUpload = ServletFileUpload.isMultipartContent(request);
		if ( isUpload ) {
			DiskFileItemFactory factory = new DiskFileItemFactory();
			ServletFileUpload upload = new ServletFileUpload(factory);
			try {   
				List<FileItem> items = upload.parseRequest(request); //解析request请求
				Iterator iter = items.iterator();
				while (iter.hasNext()) {
					   FileItem item = (FileItem) iter.next();
					   if (!item.isFormField()) {                     //如果是表单域 ，就是非文件上传元素 
						   //String fieldName = item.getFieldName();      //文件域中name属性的值
						   String filePath = item.getName();            //文件的全路径，绝对路径名加文件名           
						   //String contentType = item.getContentType(); //文件的类型
						   //long size = item.getSize();                  //文件的大小，以字节为单位 
						   File saveFile = new File(filePath);      //定义一个file指向一个具体的文件
						   FileInputStream  in = new FileInputStream(saveFile);
						   return in;
				       }
			    }
			}catch(Exception e) {}
			
		}
		return null;
	}