创建并下载Zip文件java

Question

In my application there are no of documents(pdf) for a particular tender. I need to create a zip file from those pdf files and allow user to download it.

Application is done in JavaEE with struts and mysql. when user clicks the download button this action class gets called. The code does not give any exceptions but it does not prompt user to download anything either.

Please help me find what is wrong in the code.

Following is the source code of my action class..

public class ActDownloadDocZip extends Action {
static Logger logger = Logger.getLogger(ActDownloadDocZip.class);

public ActionForward execute(ActionMapping mapping, ActionForm form,
        HttpServletRequest request, HttpServletResponse response)
        throws Exception {
    String realPath = getServlet().getServletContext().getRealPath(
            "/WEB-INF/log4jConfiguration.xml");
    DOMConfigurator.configure(realPath);
    logger.info("In ActDownloadDocZip....");
    ActionForward forward = null;
    HttpSession session = request.getSession();
    // get a db connection
    Connection conn = null;
    String[][] nameFile = null;
    String tenderNo = "";
    try {
        conn = ProxoolConnection.getProxoolConnectionSLT();
        tenderNo = request.getParameter("tenderNo");
        // File fileex=new File("xxx.zip");
        FileOutputStream zipFile = new FileOutputStream(new File("xxx.zip"));
        ZipOutputStream output = new ZipOutputStream(zipFile);
        // call getPdfFiles method here
        ILoadTenders ld = new LoadTenders();
        nameFile = ld.getPdfFileListToTender(conn, tenderNo);//this method brings back the relevant pdf file names and paths((pdfname1,pdfpath1),(pdfname2,pdfpath2))
        for (int i = 0; i < nameFile.length; i++) {
            ZipEntry zipEntry = new ZipEntry(nameFile[i][0].trim());
            output.putNextEntry(zipEntry);
            FileInputStream pdfFile = new FileInputStream(new File(
                    nameFile[i][1].trim()));
            IOUtils.copy(pdfFile, output); 
            pdfFile.close();
            output.closeEntry();
        }
        output.finish();
        output.close();
    } catch (SQLException e) {
        System.out.println("actDownloadDocZip " + e);
        logger.fatal(e.getMessage());
    } catch (Exception e) {
        System.out.println("actDownloadDocZip1 " + e);
        logger.fatal(e.getMessage());
    } finally {
        if (conn != null) {
            ProxoolConnection.closeProxoolConnectionSLT(conn);
        }
    }
    forward = mapping.findForward("publicdashboard");
    return forward;
  }
}

Answer 1

Done :) I was already there... just had to give a proper path and download it....

Here the action class again:

package com.affno.etender.frontend;

import java.io.BufferedOutputStream;
import java.io.ByteArrayOutputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.OutputStream;
import java.sql.Connection;
import java.sql.SQLException;
import java.util.zip.ZipEntry;
import java.util.zip.ZipFile;
import java.util.zip.ZipOutputStream;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;
import org.apache.commons.io.IOUtils;
import org.apache.log4j.Logger;
import org.apache.log4j.xml.DOMConfigurator;
import org.apache.struts.action.Action;
import org.apache.struts.action.ActionForm;
import org.apache.struts.action.ActionForward;
import org.apache.struts.action.ActionMapping;
import org.apache.struts.util.MessageResources;
import com.affno.util.proxool.ProxoolConnection;

public class ActDownloadDocZip extends Action {
    static Logger logger = Logger.getLogger(ActDownloadDocZip.class);

    public ActionForward execute(ActionMapping mapping, ActionForm form,
            HttpServletRequest request, HttpServletResponse response)
            throws Exception {

        String realPath = getServlet().getServletContext().getRealPath(
                "/WEB-INF/log4jConfiguration.xml");
        DOMConfigurator.configure(realPath);
        logger.info("In ActDownloadDocZip....");

        ActionForward forward = null;
        HttpSession session = request.getSession();

        // get a db connection
        Connection conn = null;

        String[][] nameFile = null;

        String tenderNo = "";

        ////
        FileOutputStream fos = null;
        ZipOutputStream zipOut = null;
        FileInputStream fis = null;

        MessageResources messages = MessageResources.getMessageResources("resources.Upload");
        String dirzip = messages.getMessage("save.dir");
        tenderNo = request.getParameter("tenderNo").trim();
        String zipFolderName =tenderNo + ".zip";
        String filepathzipped = dirzip + zipFolderName;

        try {
            conn = ProxoolConnection.getProxoolConnectionSLT();

            fos = new FileOutputStream(filepathzipped);
            zipOut = new ZipOutputStream(new BufferedOutputStream(fos));

            ILoadTenders ld = new LoadTenders();
            nameFile = ld.getPdfFileListToTender(conn, tenderNo);

            for (int i = 0; i < nameFile.length; i++){
                File input = new File(nameFile[i][1].trim());
                fis = new FileInputStream(input);
                ZipEntry ze = new ZipEntry(input.getName());
                System.out.println("Zipping the file: "+input.getName());
                zipOut.putNextEntry(ze);
                byte[] tmp = new byte[4*1024];
                int size = 0;
                while((size = fis.read(tmp)) != -1){
                    zipOut.write(tmp, 0, size);
                }
                zipOut.flush();
                fis.close();
            }
            zipOut.close();
            System.out.println("Done... Zipped the files...");
            //zip created

            //downloading the zip
            File file = new File(filepathzipped);
            if(!file.exists()){
                System.out.println("file not found");
            }
            response.setContentType("APPLICATION/OCTET-STREAM");
            response.setHeader("Content-Disposition","attachment; filename=\"" + zipFolderName + "\"");

            OutputStream out = response.getOutputStream();
            FileInputStream in = new FileInputStream(file);
            byte[] buffer = new byte[4096];
            int length;
            while ((length = in.read(buffer)) > 0){
               out.write(buffer, 0, length);
            }
            in.close();
            out.flush();    
        }
        ////
         catch (SQLException e) {
            System.out.println("actDownloadDocZip " + e);
            logger.fatal(e.getMessage());
        } catch (Exception e) {
            System.out.println("actDownloadDocZip1 " + e);
            logger.fatal(e.getMessage());
        } finally {
            if (conn != null) {
                ProxoolConnection.closeProxoolConnectionSLT(conn);
            }
        }

        forward = mapping.findForward("publicdashboard");
        /*
         * if (forward != null) { forward = new ActionForward(forward.getPath()
         * +"servlet/DownloadServlet?" + zipFile, true); }
         */
        return forward;
    }
}

Answer 2

1. Intercept the request while downloading the report and copy the download url and hit.
2. Code for prevent the direct access of the url for downloading any file

Implementation

if (param.equals("downloadfile")) {
    session = request.getSession();
    relativePath = request.getRealPath("/");
    String filePathName = relativePath + "FILES\\EXCEL\\ASC_Mapping_" + user.getLoginID() + ".zip";
    System.out.println("guddu 1 " + filePathName);

    if (filePathName == null || filePathName.equals("")) {
        throw new ServletException("File Name can't be null or empty");
    }

    File file1 = new File(filePathName);
    if (!file1.exists()) {
        throw new ServletException("File doesn't exists on server.");
    }

    response.setContentType("APPLICATION/OCTET-STREAM");
    response.setHeader("Content-Disposition", "attachment;filename=ASC_Mapping_" + user.getLoginID() + ".zip");

    FileInputStream fileInputStream = new FileInputStream(file1);
    OutputStream os = response.getOutputStream();
    byte[] bufferData = new byte[4096];
    int read = 0;
    while ((read = fileInputStream.read(bufferData)) > 0) {
        os.write(bufferData, 0, read);
    }

    os.close();
    fileInputStream.close();
    response.flushBuffer();
}