为什么我上传的文件名是空的？ jsp/servlet

Question

Ι 使用以下 servlet 上传照片并且它有效。但是当我在 jsp 页面中打印照片名称时，它是空的。我需要它以便将它保存在我的数据库中。有什么想法吗？

import java.io.File;
import java.io.IOException;
import java.util.List;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import org.apache.commons.fileupload.FileItem;
import org.apache.commons.fileupload.disk.DiskFileItemFactory;
import org.apache.commons.fileupload.servlet.ServletFileUpload;

public class FileUploadHandler extends HttpServlet {
    private final String UPLOAD_DIRECTORY = "C:\Program Files\Apache Software Foundation\Tomcat 6.0\webapps\ismgroup9\fileUpload";

@Override
protected void doPost(HttpServletRequest request, HttpServletResponse response)
        throws ServletException, IOException {

    if(ServletFileUpload.isMultipartContent(request)){
        try {
            List<FileItem> multiparts = new ServletFileUpload(new DiskFileItemFactory()).parseRequest(request);

            for(FileItem item : multiparts){
                if(!item.isFormField()){
                    String name = new File(item.getName()).getName();
                    item.write( new File(UPLOAD_DIRECTORY + File.separator + name));
                    request.setAttribute("photoname", name);
                }
            }

           request.setAttribute("message", "File Uploaded Successfully");
        } catch (Exception ex) {
           request.setAttribute("message", "File Upload Failed due to " + ex);
        }

    }else{
        request.setAttribute("message", "Sorry this Servlet only handles file upload request");
    }

    request.getRequestDispatcher("/uploadfileController.jsp").forward(request, response);

}

}

Answer 1

根据您的评论，您似乎使用了

request.getAttribute("photoName");
//                         ^here is the problem

但您的属性设置名称为 photoname。

request.setAttribute("photoname", name);

Java 区分大小写，因此 photoname 和 photoName 不是相同的名称。始终仔细检查您的变量名称。

为什么我上传的文件名是空的？ jsp/servlet

Why is the name of the file I upload null? jsp/servlet

java

jsp

servlets

file-upload