在JSP/Servlet中使用Apache命令文件上载API的文件上载问题

Question

我正在尝试使用org.apache.commons.fileupload上传文件。但是我不知道，我犯了什么错误，我在我的servlet中得到了以下错误。请任何人在this..this上帮助我，这是我得到的错误。

     javax.servlet.ServletException: Servlet execution threw an exception


 root cause 

 java.lang.NoClassDefFoundError: org/apache/commons/io/output/DeferredFileOutputStream
org.apache.commons.fileupload.disk.DiskFileItemFactory.createItem(DiskFileItemFactory.java:199)
org.apache.commons.fileupload.FileUploadBase.parseRequest(FileUploadBase.java:361)
org.apache.commons.fileupload.servlet.ServletFileUpload.parseRequest(ServletFileUpload.java:126)
upload1.doPost(upload1.java:34)
javax.servlet.http.HttpServlet.service(HttpServlet.java:637)
     javax.servlet.http.HttpServlet.service(HttpServlet.java:717)

这是我的servlet代码

   if (ServletFileUpload.isMultipartContent(req)) {

         // Create a factory for disk-based file items
         FileItemFactory factory = new DiskFileItemFactory();

         // Create a new file upload handler
         ServletFileUpload upload = new ServletFileUpload(factory);

         // Parse the request
         try {
             List<FileItem> items = upload.parseRequest(req);
             for (FileItem item : items) {
                 // process only file upload - discard other form item types
                 if (item.isFormField()) continue;

                 String fileName = item.getName();
                 // get only the file name not whole path
                 if (fileName != null) {
                    // fileName = FilenameUtils. getName(fileName);
                 }


             }
         } catch (Exception e) {
             res.sendError(HttpServletResponse.SC_INTERNAL_SERVER_ERROR,
                     "An error occurred while creating the file : " + e.getMessage());
         }

     } else {
         res.sendError(HttpServletResponse.SC_UNSUPPORTED_MEDIA_TYPE,
                         "Request contents type is not supported by the servlet.");
     }

和表单

          <form method="POST" action="upload1" enctype="multipart/form-data" >

谢谢你

Answer 1

org/apache/commons/io/output/DeferredFileOutputStream：

java.lang.NoClassDefFoundError

它只是告诉您在运行时类路径中缺少提到的类。正如包名所暗示的，它是Apache Commons IO的一部分。您可以从http://commons.apache.org/io对其进行download。解压下载的压缩包，将JAR文件放入/WEB-INF/lib，重新构建/重新部署/重新启动webapp/服务器，这个错误应该会消失。