Java Servlet – jQuery File Upload (multiple, drag&drop, progress…) | HMKCode

package com.hmkcode;

import java.io.IOException;

import java.util.Collection;

import java.util.LinkedList;

import java.util.List;

import javax.servlet.ServletException;

import javax.servlet.http.HttpServletRequest;

import javax.servlet.http.Part;

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;

import com.hmkcode.vo.FileMeta;

public class MultipartRequestHandler {

    public static List<FileMeta> uploadByJavaServletAPI(HttpServletRequest request) throws IOException, ServletException{

        List<FileMeta> files = new LinkedList<FileMeta>();

        // 1. Get all parts

        Collection<Part> parts = request.getParts();

        // 2. Get paramter "twitter"

        String twitter = request.getParameter("twitter");

        // 3. Go over each part

        FileMeta temp = null;

        for(Part part:parts){  

            // 3.1 if part is multiparts "file"

            if(part.getContentType() != null){

                // 3.2 Create a new FileMeta object

                temp = new FileMeta();

                temp.setFileName(getFilename(part));

                temp.setFileSize(part.getSize()/1024 +" Kb");

                temp.setFileType(part.getContentType());

                temp.setContent(part.getInputStream());

                temp.setTwitter(twitter);

                // 3.3 Add created FileMeta object to List<FileMeta> files

                files.add(temp);

            }

        }

        return files;

    }

    public static List<FileMeta> uploadByApacheFileUpload(HttpServletRequest request) throws IOException, ServletException{

        List<FileMeta> files = new LinkedList<FileMeta>();

        // 1. Check request has multipart content

        boolean isMultipart = ServletFileUpload.isMultipartContent(request);

        FileMeta temp = null;

        // 2. If yes (it has multipart "files")

        if(isMultipart){

            // 2.1 instantiate Apache FileUpload classes

            DiskFileItemFactory factory = new DiskFileItemFactory();

            ServletFileUpload upload = new ServletFileUpload(factory);

            // 2.2 Parse the request

            try {

                // 2.3 Get all uploaded FileItem

                List<FileItem> items = upload.parseRequest(request);

                String twitter = "";

                // 2.4 Go over each FileItem

                for(FileItem item:items){

                    // 2.5 if FileItem is not of type "file"

                    if (item.isFormField()) {

                        // 2.6 Search for "twitter" parameter

                        if(item.getFieldName().equals("twitter"))

                            twitter = item.getString();

                    } else {

                        // 2.7 Create FileMeta object

                        temp = new FileMeta();

                        temp.setFileName(item.getName());

                        temp.setContent(item.getInputStream());

                        temp.setFileType(item.getContentType());

                        temp.setFileSize(item.getSize()/1024+ "Kb");

                        // 2.7 Add created FileMeta object to List<FileMeta> files

                        files.add(temp);

                    }

                }

                // 2.8 Set "twitter" parameter

                for(FileMeta fm:files){

                    fm.setTwitter(twitter);

                }

            } catch (FileUploadException e) {

                e.printStackTrace();

            }

        }

        return files;

    }

    // this method is used to get file name out of request headers

    //

    private static String getFilename(Part part) {

        for (String cd : part.getHeader("content-disposition").split(";")) {

            if (cd.trim().startsWith("filename")) {

                String filename = cd.substring(cd.indexOf('=') + 1).trim().replace("\"", "");

                return filename.substring(filename.lastIndexOf('/') + 1).substring(filename.lastIndexOf('\\') + 1); // MSIE fix.

            }

        }

        return null;

    }

}