读取FTP文件，并打包成压缩包下载

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();
    }
}
 
}