读取FTP文件，并打包成压缩包下载

桃扇骨 2022-05-15 02:37 396阅读 0赞

import java.io.*;
    import java.net.SocketException;
    import java.net.URLEncoder;
    import java.util.List;
    import java.util.zip.ZipEntry;
    import java.util.zip.ZipOutputStream;
    
    import org.apache.commons.net.ftp.FTPClient;
    import org.apache.commons.net.ftp.FTPFile;
    import org.apache.commons.net.ftp.FTPReply;

public class FtpFileUtil {

/**
     * 获取FTPClient对象
     * @param ftpAddress FTP主机服务器地址
     * @param ftpHost 端口号
     * @param ftpUsername 用户名
     * @param ftpPassword 密码
     * @return FTPClient对象
     */
    public static FTPClient getFTPClient(String ftpAddress, int ftpHost, String ftpUsername, String ftpPassword) {
        FTPClient ftpClient = new FTPClient();
        try {
            ftpClient.setDataTimeout(60000);       //设置传输超时时间为60秒
            ftpClient.setConnectTimeout(60000);
            ftpClient.connect(ftpAddress, ftpHost);// 连接FTP服务器
            ftpClient.login(ftpUsername, ftpPassword);// 登陆FTP服务器
            if (!FTPReply.isPositiveCompletion(ftpClient.getReplyCode())) {
                logger.info("未连接到FTP，用户名或密码错误。");
                ftpClient.disconnect();
            } else {
                logger.info("FTP连接成功。");
            }
        } catch (SocketException e) {
            e.printStackTrace();
            logger.info("FTP的IP地址可能错误，请正确配置。");
        } catch (IOException e) {
            e.printStackTrace();
            logger.info("FTP的端口错误,请正确配置。");
        }
        return ftpClient;
    }

/**
     *实现文件打包压缩下载
     * @param FTP_ADDRESS
     * @param FTP_PORT
     * @param FTP_USERNAME
     * @param FTP_PASSWORD
     * @param response  服务器响应对象HttpServletResponse
     * @param zipname 压缩包的文件名
     * @param ftpPath ftp文件路径
     * @param ftpFileList 要下载的文件名集合
     * @param namelist 压缩后的文件名集合
     */
    public static void zipDownloadFile(String FTP_ADDRESS,int FTP_PORT,String FTP_USERNAME,String FTP_PASSWORD,HttpServletResponse response, String zipname, String ftpPath,List<String>ftpFileList, List<String> namelist) {
        FTPClient ftp = getFTPClient(FTP_ADDRESS, FTP_PORT, FTP_USERNAME, FTP_PASSWORD);
        byte[] buf = new byte[1024];
        try {
            ftp.setControlEncoding("UTF-8");
            ftp.setFileType(FTPClient.BINARY_FILE_TYPE);
            ftp.enterLocalPassiveMode();
            ftp.changeWorkingDirectory(ftpPath);
            File zipFile = new File("123");
            ZipOutputStream zipOut = new ZipOutputStream(new FileOutputStream(zipFile));
            for (int i=0;i< ftpFileList.size();i++) {
                ZipEntry entry = new ZipEntry((i+1)+"_"+namelist.get(i));
                zipOut.putNextEntry(entry);
                InputStream bis = ftp.retrieveFileStream(ftpFileList.get(i));
                if (bis != null) {
                    int readLen = -1;
                    while ((readLen = bis.read(buf, 0, 1024)) != -1) {
                        zipOut.write(buf, 0, readLen);
                    }
                    zipOut.closeEntry();
                    bis.close();
                    ftp.completePendingCommand();
                    //调用ftp.retrieveFileStream这个接口后，一定要手动close掉返回的InputStream，然后再调用completePendingCommand方法
                    // ，若不是按照这个顺序，则会导致后面对FTPClient的操作都失败
                }
            }
            zipOut.close();
            ftp.logout();
            //下载
            int len;
            FileInputStream zipInput =new FileInputStream(zipFile);
            OutputStream out = response.getOutputStream();
            response.setContentType("application/octet-stream");
            response.addHeader("Content-Disposition", "attachment; filename="
                    + URLEncoder.encode(zipname, "UTF-8") + ".zip");
            while ((len=zipInput.read(buf))!= -1){
                out.write(buf,0,len);
            }
            zipInput.close();
            out.flush();
            out.close();
                        //删除压缩包
            zipFile.delete();
        } catch (Exception e) {
            logger.error("文件打包下载有误: " + e.getLocalizedMessage());
            e.printStackTrace();
        }
    }