创建并下载 Zip 文件 java

create and download the Zip file java

提问by Bhugy

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.

在我的申请中，没有特定投标的文件（pdf）。我需要从这些 pdf 文件创建一个 zip 文件并允许用户下载它。

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.

应用程序是在 JavaEE 中使用 struts 和 mysql 完成的。当用户单击下载按钮时，会调用此操作类。该代码没有给出任何例外，但也不会提示用户下载任何内容。

Please help me find what is wrong in the code.

请帮我找出代码中的问题。

Following is the source code of my action class..

以下是我的动作类的源代码..

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;
  }
}

采纳答案by Bhugy

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

完成 :) 我已经在那里了......只需要给出一个正确的路径并下载它......

Here the action class again:

这里又是动作类：

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;
    }
}

回答by Mr. GK

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

1. 下载报告时拦截请求，复制下载地址，点击。
2. 防止直接访问url下载任何文件的代码

Implementation

执行

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();
}