public void scpRemoteFileToLocal()

in src/core-common/src/main/java/org/apache/kylin/common/util/SSHClient.java [170:266]
72 lines of code
14 McCabe index (conditional complexity)

    public void scpRemoteFileToLocal(String remoteFile, String localTargetDirectory) throws Exception {
        FileInputStream fis = null;
        try {
            logger.info("SCP file " + remoteFile + " to " + localTargetDirectory);

            Session session = newJSchSession();
            session.connect();

            String prefix = null;

            if (new File(localTargetDirectory).isDirectory()) {
                prefix = localTargetDirectory + File.separator;
            }

            // exec 'scp -f rfile' remotely
            String command = "scp -p -f " + remoteFile;
            Channel channel = session.openChannel("exec");
            ((ChannelExec) channel).setCommand(command);

            // get I/O streams for remote scp
            OutputStream out = channel.getOutputStream();
            InputStream in = channel.getInputStream();

            channel.connect();

            byte[] buf = new byte[1024];

            // send '\0'
            buf[0] = 0;
            out.write(buf, 0, 1);
            out.flush();

            while (true) {
                int c = checkAck(in);
                if (c != 'T') {
                    break;
                }
                long modTime = getModifyTime(out, in, buf);

                do {
                    c = checkAck(in);
                } while (c != 'C');

                long fileSize = 0L;
                fileSize = getFilesize(out, in, buf, fileSize);

                String file;
                for (int i = 0; true; i++) {
                    in.read(buf, i, 1);
                    if (buf[i] == (byte) 0x0a) {
                        file = new String(buf, 0, i, Charset.defaultCharset());
                        break;
                    }
                }

                logger.info("file-size=" + fileSize + ", file=" + file);

                // read a content of lfile
                try (FileOutputStream fos = new FileOutputStream(prefix == null ? remoteFile : prefix + file)) {
                    int foo;
                    while (true) {
                        foo = buf.length < fileSize ? buf.length : (int) fileSize;
                        foo = in.read(buf, 0, foo);
                        if (foo < 0) {
                            // error
                            break;
                        }
                        fos.write(buf, 0, foo);
                        fileSize -= foo;
                        if (fileSize == 0L) {
                            break;
                        }
                    }

                    if (checkAck(in) != 0) {
                        Unsafe.systemExit(0);
                    }

                    File tempFile = new File(prefix + file);

                    if (!tempFile.setLastModified(modTime * 1000)) {
                        logger.warn("update {} modify time failed", file);
                    }

                    // send '\0'
                    buf[0] = 0;
                    out.write(buf, 0, 1);
                    out.flush();
                }
            }

            channel.disconnect();
            session.disconnect();
        } finally {
            IOUtils.closeQuietly(fis);
        }
    }