Question

The following HTML snippet submits the file to UploadHandler which is a servlet. Then there is a caption box that also needs to be handled. I can handle the caption box in UploadHandler and then open the connection with the database and submit it there. But i don’t want to do this . Let upload handler handle uploading of files. Then what is the alternative ? How do i submit the caption into the table ? I want to create a sense of parallelism in handling these two jobs.

<form method="post" action="UploadHandler" enctype="multipart/form-data">
        <table>

            <tr>
                <td> <strong> Browse photo to submit </strong> </td>
                <td> <input type="file" name="ImageToUpload" value="Upload Photo"/> </td>
            </tr>

            <tr>
                <td> <strong> Give a Caption to this photo </strong>  </td>
                <td> <input type="text" name="caption box" size="40" /></td>
            </tr>

            <tr colspan="2">
                <td> <input type="submit" value="submit photo"/> </td>
            </tr>

        </table>
    </form>

Is there any way that when i click to submit 2 different jobs they are handled by 2 different servlets ? Creating a new thread from UploadaHandler doesn’t seem a good idea.

After the comment by @Luiggi Mendoza :

Servlet that handles Uploading of files :

package projectcodes;

import javax.servlet.*;
import javax.servlet.http.*;
import java.io.IOException;
import java.io.PrintWriter;
import java.io.File;
import java.util.List;
import java.util.Iterator;
import org.apache.commons.fileupload.*;
import org.apache.commons.fileupload.disk.DiskFileItemFactory;
import org.apache.commons.fileupload.servlet.ServletFileUpload;
import org.apache.commons.io.FilenameUtils;

public class UploadHandler extends HttpServlet {
@Override
public void doPost(HttpServletRequest request,HttpServletResponse response) throws IOException,ServletException {
    response.setContentType("text/plain");
    String path = request.getParameter("ImageToUpload");
    PrintWriter writer = response.getWriter();
    try {
        Boolean isMultipart = ServletFileUpload.isMultipartContent(request);
        if(!isMultipart) {
            Boolean AttemptToUploadFile = true;
            RequestDispatcher rd = request.getRequestDispatcher("portfolio_one.jsp");
            request.setAttribute("UploadAttempt", AttemptToUploadFile);
            rd.forward(request, response);
        } else {
            DiskFileItemFactory diskFileItem = new DiskFileItemFactory();
            ServletFileUpload fileUpload = new ServletFileUpload(diskFileItem);
            List list = null;

            try {
                list = fileUpload.parseRequest(request);
            }catch(Exception exc) {
                Boolean AttemptToUploadFile = true;
                RequestDispatcher rd = request.getRequestDispatcher("portfolio_one.jsp");
                request.setAttribute("UploadAttempt", AttemptToUploadFile);
                rd.forward(request, response);
            }

            Iterator iterator = list.iterator();
            while(iterator.hasNext()) {
                String emailOfTheUser = null;
                FileItem fileItem = (FileItem)iterator.next();
                if(!fileItem.isFormField()) {
                    String fieldName = fileItem.getFieldName();
                    String fileName = FilenameUtils.getName(fileItem.getName());
                    HttpSession session = request.getSession();
                    if(!session.isNew()) {
                        emailOfTheUser = (String)session.getAttribute("Email");
                    }
                    File file = new File("/home/non-admin/project uploads/project users/" + emailOfTheUser ,fileName);
                    fileItem.write(file);
                    RequestDispatcher rd = request.getRequestDispatcher("portfolio_one.jsp");
                    String message = "File Uploaded successfully !";
                    request.setAttribute("SuccessMessage", message);
                    rd.forward(request, response);
                }
            }
        }
    }catch(Exception exc) {
        Boolean AttemptToUploadFile = true;
        RequestDispatcher rd = request.getRequestDispatcher("portfolio_one.jsp");
        request.setAttribute("UploadAttempt", AttemptToUploadFile);
        rd.forward(request, response);
    }
}

}

Answer 1

I guess you can if you forward from the first to the 2nd servlet, using:

getServletContext().getRequestDispatcher("/2ndServlet").forward(req, res);

But this is not a good idea, as it might trigger filter, the response may already by committed, etc.

What you should do is extract the functionality of the 2nd servlet in a helper class, and just invoke it, as a simple java method invocation, from the 1st servlet.