Java FTPClient.retrieveFile方法代码示例

import org.apache.commons.net.ftp.FTPClient; //导入方法依赖的package包/类
public static byte[] download(String url, int port, String username, String password, String remotePath,
		String fileName) throws IOException {
	FTPClient ftp = new FTPClient();
	ftp.setConnectTimeout(5000);
	ftp.setAutodetectUTF8(true);
	ftp.setCharset(CharsetUtil.UTF_8);
	ftp.setControlEncoding(CharsetUtil.UTF_8.name());
	try {
		ftp.connect(url, port);
		ftp.login(username, password);// 登录
		if (!FTPReply.isPositiveCompletion(ftp.getReplyCode())) {
			ftp.disconnect();
			throw new IOException("login fail!");
		}
		ftp.changeWorkingDirectory(remotePath);
		ftp.setFileType(FTPClient.BINARY_FILE_TYPE);
		FTPFile[] fs = ftp.listFiles();
		for (FTPFile ff : fs) {
			if (ff.getName().equals(fileName)) {
				try (ByteArrayOutputStream is = new ByteArrayOutputStream();) {
					ftp.retrieveFile(ff.getName(), is);
					byte[] result = is.toByteArray();
					return result;
				}
			}
		}

		ftp.logout();
	} finally {
		if (ftp.isConnected()) {
			ftp.disconnect();
		}
	}
	return null;
}
 

import org.apache.commons.net.ftp.FTPClient; //导入方法依赖的package包/类
/**
 * 下载文件
 *
 * @param remoteDir      远程操作目录
 * @param remoteFileName 远程下载文件名
 * @param downloadFile   下载文件
 * @return 下载结果<br> true - 下载成功<br>
 * false - 下载失败
 */
public boolean download(String remoteDir, String remoteFileName, File downloadFile) {
    FTPClient ftp = null;
    try {
        ftp = initFtpClient(remoteDir);
        if (ftp == null) {
            logger.debug("ftp初始化失败");
            return false;
        }
        try (OutputStream os = new FileOutputStream(downloadFile)) {
            boolean storeRet = ftp.retrieveFile(remoteFileName, os);
            if (!storeRet) {
                logger.debug("下载文件失败");
                return false;
            }
        }
        return true;
    } catch (IOException e) {
        logger.error("FTP操作异常", e);
        return false;
    } finally {
        close(ftp);
    }
}
 

import org.apache.commons.net.ftp.FTPClient; //导入方法依赖的package包/类
/**
 * 从FTP服务器下载指定的文件至本地
 * 
 * @author gaoxianglong
 */
public boolean downloadFile(File file) {
	boolean result = false;
	FTPClient ftpClient = ftpConnManager.getFTPClient();
	if (null == ftpClient || !ftpClient.isConnected()) {
		return result;
	}
	try (BufferedOutputStream out = new BufferedOutputStream(
			new FileOutputStream(System.getProperty("user.home") + "/" + file.getName()))) {
		result = ftpClient.retrieveFile(file.getName(), out);
		if (result) {
			result = true;
			log.info("file-->" + file.getPath() + "成功从FTP服务器下载");
		}
	} catch (Exception e) {
		log.error("error", e);
	} finally {
		disconnect(ftpClient);
	}
	return result;
}
 

import org.apache.commons.net.ftp.FTPClient; //导入方法依赖的package包/类
public static boolean downloadFile(String url, int port, String username, String password,
                                   String remotePath, String fileName, String localPath) {
    boolean success = false;
    FTPClient ftp = new FTPClient();
    try {
        int reply;
        ftp.connect(url, port);
        ftp.login(username, password);
        reply = ftp.getReplyCode();
        if (!FTPReply.isPositiveCompletion(reply)) {
            ftp.disconnect();
            return success;
        }
        ftp.changeWorkingDirectory(remotePath);
        FTPFile[] fs = ftp.listFiles();
        System.out.println(fs.length);
        for (FTPFile ff : fs) {
            System.out.println(ff.getName());
            if (ff.getName().equals(fileName)) {
                File localFile = new File(localPath + "/" + ff.getName());
                OutputStream is = new FileOutputStream(localFile);
                ftp.retrieveFile(ff.getName(), is);
                is.close();
            }
        }
        ftp.logout();
        success = true;
    } catch (IOException e) {
        e.printStackTrace();
    } finally {
        if (ftp.isConnected()) {
            try {
                ftp.disconnect();
            } catch (IOException ioe) {
            }
        }
    }
    return success;
}
 

import org.apache.commons.net.ftp.FTPClient; //导入方法依赖的package包/类
/**
 * FTP下载
 * 
 * @author wangwei
 */
public void downloadFile(String downloadFilename, String remoteFolder,
		OutputStream outputStream, HttpServletResponse response)
		throws Exception {

	// 连接FTP服务器
	FTPClient ftp = this.connectFTPServer();

	try {

		this.changeDirectory(remoteFolder);
		FTPFile[] fs = ftp.listFiles();
		for (int i = 0; i < fs.length; i++) {
			FTPFile ff = fs[i];
			if (ff.getName().equals(downloadFilename)) {
				response.setHeader(
						"Content-disposition",
						"attachment;filename="
								+ URLEncoder.encode(downloadFilename,
										"utf-8"));
				boolean result = ftp.retrieveFile(new String(ff.getName()
						.getBytes("GBK"), "ISO-8859-1"), outputStream);
				if (!result) {
					throw new Exception("FTP文件下载失败!");
				}
				outputStream.flush();
			}
		}

	} catch (Exception e) {
		throw e;
	} finally {
		if (outputStream != null) {
			outputStream.close();
		}
	}

}