Node.js使用ftp连接远程ftp服务器枚举和下载文件示例

示例代码：

var Ftp = require('ftp');
var fs = require('fs');
var path = require('path');

// 首先判断参数中是否包含{dateString}
var args = process.argv.splice(2);
if (args.length < 1) {
    console.error('usage: node ftpFilesGetter.js [dateString]');
    process.exit(1);
}
var dateString = args[0];

// 根据dateString获得nextDay
var year = parseInt(dateString.substring(0,4)), 
    month = parseInt(dateString.substring(4,6)),
    day = parseInt(dateString.substring(6,8));
var lastday;
if (month == 2) {
    if (year % 400 == 0 || year % 4 == 0 && year % 100 != 0) lastday = 29;
    else lastday = 28;
} else if ([1, 3, 5, 7, 8, 10, 12].indexOf(month) != -1) lastday = 31;
else lastday = 30;
if (day < lastday) day ++;
else {
    month ++;
    if (month > 12) {
        month = 1;
        year ++;
    }
}
if (month < 10) month = '0' + month;
if (day < 10) day = '0' + day;
var nextDay = `${year}${month}${day}`;

// 判断下载文件所在的文件夹是否存在，如果不存在则创建
var rootDir = 'D:/test'; if (fs.existsSync(rootDir) == false) fs.mkdirSync(rootDir);
if (fs.existsSync(`${rootDir}/report_log`) == false) fs.mkdirSync(`${rootDir}/report_log`);
if (fs.existsSync(`${rootDir}/report`) == false) fs.mkdirSync(`${rootDir}/report`);
var logDir = `${rootDir}/report_log/${dateString}`; if (fs.existsSync(logDir) == false) fs.mkdirSync(logDir);
var nextDayLogDir = `${rootDir}/report_log/${nextDay}`; if (fs.existsSync(nextDayLogDir) == false) fs.mkdirSync(nextDayLogDir);
var dataDir = `${rootDir}/report/${dateString}`; if (fs.existsSync(dataDir) == false) fs.mkdirSync(dataDir);

// 登陆ftp
var connectionProperties = {
    host: 'xxx.xxx.xxx.xxx',
    user: 'stp_username',
    password: 'ftp_password'
};
var ftp = new Ftp();
ftp.on('ready', ()=>{
    console.log('connect to ftp ok!');
    var needFileList = [];
    var callback = function() { 
        console.log(`2 log files + many data files, total : ${needFileList.length} files!`);
        var cnt = 0;
        needFileList.forEach(file => {
            var filename = file.substring(file.lastIndexOf('/') + 1);
            var localFile;
            if (file.substring(0,12) == `log/${dateString}`) {  // 今天的log
                localFile = `${logDir}/${filename}`;
            }
            else if (file.substring(0,12) == `log/${nextDay}`) {    // 明天的log
                localFile = `${nextDayLogDir}/${filename}`;
            } else {    // data
                localFile = `${dataDir}/${filename}`;
            }
            ftp.get(file, (err, stream)=>{
                stream.once('close', ()=>{
                    cnt ++;
                    console.log(`(${cnt}) download ${file} --> ${localFile} succeed!`);
                    if (cnt >= needFileList.length) {
                        console.log('process successfully end!');
                        process.exit(0);
                    }
                });
                stream.pipe(fs.createWriteStream(localFile));
            });

        });
    }
    ftp.list(`log/${dateString}`, (err, list)=>{
        list.forEach(item => needFileList.push(`log/${dateString}/${item.name}`));
        ftp.list(`log/${nextDay}`, (err, list)=>{
            list.forEach(item => needFileList.push(`log/${nextDay}/${item.name}`));
            ftp.list(`sdata/S-999000`, (err, list)=>{
                var sysIdList = list.map(item => { return item.name });
                var cnt1 = 0; // cnt1用于记录sysId的个数，当等于sysIdList.length的时候说明遍历完了
                var tmpDirList = [];
                sysIdList.forEach(sysId => {
                    ftp.list(`sdata/S-999000/${sysId}`, (err, list)=>{
                        cnt1 ++;
                        list.forEach(item => tmpDirList.push(`sdata/S-999000/${sysId}/${item.name}`));
                        if (cnt1 >= sysIdList.length) {
                            var cnt2 = 0;
                            tmpDirList.forEach(tmpDir =>{
                                ftp.list(`${tmpDir}/${dateString}`, (err, list)=>{
                                    cnt2 ++;
                                    list.forEach(item => needFileList.push(`${tmpDir}/${dateString}/${item.name}`));
                                    if (cnt2 >= tmpDirList.length) {
                                        callback();
                                    }
                                });
                            });
                        }
                    });
                });
            });
        });
    });
});
ftp.connect(connectionProperties);