Why is this simple file upload not working? JSF

Question

Why is this code not working? I always get size() = 0, whenever i upload file.

xhtml file :-

<?xml version='1.0' encoding='UTF-8' ?>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml"
      xmlns:h="http://java.sun.com/jsf/html">
    <h:head>
        <title>Abc</title>

    </h:head>
    <h:body>
        <center>

            <form method="post" enctype="multipart/form-data" id="form" action="/upload/uploadFile">
                    <input type="file"/>    <br/>
                    <input type="Submit" value="upload"/>
            </form>

        </center>
    </h:body>
</html>

This is my servlet :-

package servlets;

import java.io.IOException;
import java.util.List;
import java.util.logging.Level;
import java.util.logging.Logger;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
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.FileUploadException;
import org.apache.commons.fileupload.disk.DiskFileItemFactory;
import org.apache.commons.fileupload.servlet.ServletFileUpload;


@WebServlet(name="uploadFile", urlPatterns={"/uploadFile"})
public class uploadFile extends HttpServlet {


    protected void processRequest(HttpServletRequest request, HttpServletResponse response)
    throws ServletException, IOException, FileUploadException {
        System.out.println("executed!");
        List<FileItem> items = new ServletFileUpload(new DiskFileItemFactory()).parseRequest(request);
        System.out.println(items.size());
         for (FileItem item : items) {
                if (!item.isFormField()) {
                    System.out.println("Name: " + item.getName());
                    System.out.println("Size: " + item.getSize());
                    System.out.println("Type: " + item.getContentType());
                }
            }
    } 


    @Override
    protected void doGet(HttpServletRequest request, HttpServletResponse response)
    throws ServletException, IOException {
        try {
            processRequest(request, response);
        } catch (FileUploadException ex) {
            ex.printStackTrace();
        }
    } 


    @Override
    protected void doPost(HttpServletRequest request, HttpServletResponse response)
    throws ServletException, IOException {
        try {
            processRequest(request, response);
        } catch (FileUploadException ex) {
            ex.printStackTrace();
        }
    }


    @Override
    public String getServletInfo() {
        return "Short description";
    }

}

Update:

1) If i just add name = "something" to input type = "file", then it works fine. What logic can be there behind this?

2) If i use h:form instead of form, then it doesn't work (even my actionListener method doesn't get executed). What reason is there behind this? I read that h:form is not designed to handle multipart/form-data request. Is it true?

Try this thread it might broaden your scope [stackoverflow.com/questions/11954181/… [1]: stackoverflow.com/questions/11954181/… — Cocoa Butter

McDowell McDowell · Accepted Answer · 2010-05-24T07:57:59

1) If i just add name = "something" to input type = "file, then it works fine. What logic can be there behind this :d?

The name is required to distinguish the submitted value from other values - otherwise, how would you identify the parameter in the request?

2) If i use h:form instead of form, then it doesn't work (even my actionListener method doesn't get executed). What reason is there behind this? I read that h:form is not designed to handle multipart/form-data request. Is it true?

You're trying to mix JSF controls and plain HTML elements. If you don't hit the JSF servlet, don't expect the JSF lifecycle to be executed. JSF forms can support file upload - many JSF component libraries provide such controls.

Why is this simple file upload not working? JSF

2 Answers