const http = require(‘http‘);http.createServer( (req, res) => {  //...}).listen(3000);

//demo1.js‘use strict‘;const Readable = require(‘stream‘).Readable;const rs = Readable();const s = ‘VaJoy‘;const l = s.length;let i = 0;rs._read = ()=>{    if(i == l){        rs.push(‘ is my name‘);        return rs.push(null)    }    rs.push(s[i++])};rs.pipe(process.stdout);

//demo2var http = require(‘http‘);var fs = require(‘fs‘);var server = http.createServer(function (req, res) {    fs.readFile(__dirname + ‘/data.txt‘, function (err, data) {        res.end(data);    });});server.listen(3000);

var server2 = http.createServer(function (req, res) {    var stream = fs.createReadStream(__dirname + ‘/data.txt‘);    stream.pipe(res);});server2.listen(4000);

readableStream.pipe(dst)

var server2 = http.createServer(function (req, res) {    var stream = fs.createReadStream(__dirname + ‘/data.txt‘);    stream.pipe(res);});server2.listen(4000);

var Readable = require(‘stream‘).Readable;var rs = new Readable;rs.push(‘servers ‘);rs.push(‘are listening on\n‘);rs.push(‘3000 and 4000\n‘);rs.push(null);rs.pipe(process.stdout);

‘use strict‘;const Readable = require(‘stream‘).Readable;const rs = Readable();const s = ‘VaJoy‘;const l = s.length;let i = 0;rs._read = ()=>{    if(i == l){        rs.push(‘ is my name‘);        return rs.push(null)    }    rs.push(s[i++])};rs.pipe(process.stdout);

//ext1const fs = require(‘fs‘);const zlib = require(‘zlib‘);const r = fs.createReadStream(‘data.txt‘);const z = zlib.createGzip();const w = fs.createWriteStream(‘data.txt.gz‘);r.pipe(z).pipe(w);

//demo3const Readable = require(‘stream‘).Readable;class ToReadable extends Readable {    constructor(iterator) {        super();        this.iterator = iterator    }    _read() {        const res = this.iterator.next();        if (res.done) {            // 迭代结束，顺便结束可读流            this.push(null)        }        setTimeout(() => {            // 将数据添加到流中            this.push(res.value + ‘\n‘)        }, 0)    }}const gen = function *(a){    let count = 5,        res = a;    while(count--){        res = res*res;        yield res    }};const readable = new ToReadable(gen(2));// 监听`data`事件，一次获取一个数据readable.on(‘data‘, data =http://www.mamicode.com/> process.stdout.write(data));// 可读流消耗完毕readable.on(‘end‘, () => process.stdout.write(‘readable stream ends~‘));

        if (res.done) {            // 直接 return            return this.push(null)        }        this.push(res.value + ‘\n‘)

src.pipe(writableStream)

//demo4const Writable = require(‘stream‘).Writable;const writable = Writable();writable._write = (chunck, enc, next) => {    // 输出打印    process.stdout.write(chunck.toString().toUpperCase());    // 写入完成时，调用`next()`方法通知流传入下一个数据    process.nextTick(next)};// 所有数据均已写入底层writable.on(‘finish‘, () => process.stdout.write(‘DONE‘));// 将一个数据写入流中writable.write(‘a‘ + ‘\n‘);writable.write(‘b‘ + ‘\n‘);writable.write(‘c‘ + ‘\n‘);// 再无数据写入流时，需要调用`end`方法writable.end();

//demo5const Duplex = require(‘stream‘).Duplex;const duplex = Duplex();duplex._read = function () {    var date = new Date();    this.push( date.getFullYear().toString() );    this.push(null)};duplex._write = function (buf, enc, next) {    console.log( buf.toString() + ‘\n‘ );    next()};duplex.on(‘data‘, data =http://www.mamicode.com/> console.log( data.toString() ));duplex.write(‘the year is‘);duplex.end();

//demo6const Transform = require(‘stream‘).Transform;class SetName extends Transform {    constructor(name) {        super();        this.name = name || ‘‘    }    // .write接口写入的数据，处理后直接从 data 事件的回调中可取得    _transform(buf, enc, next) {        var res = buf.toString().toUpperCase();        this.push(res + this.name + ‘\n‘);        next()    }}var transform = new SetName(‘VaJoy‘);transform.on(‘data‘, data =http://www.mamicode.com/> process.stdout.write(data));transform.write(‘my name is ‘);transform.write(‘here is ‘);transform.end();

//demo7var Stream = require(‘stream‘);var stream = new Stream();stream.readable = true; //告诉 .pipe 这是个可读流var c = 64;var iv = setInterval(function () {    if (++c >= 75) {        clearInterval(iv);        stream.emit(‘end‘);    }    else stream.emit(‘data‘, String.fromCharCode(c));}, 100);stream.pipe(process.stdout);

createServer(function(q,s) {  // ADVISORY only!  q.pause()  session(q, function(ses) {    q.on(‘data‘, handler)    q.resume()  })})

//demo8writable._write = (chunck, enc, next) => {    // 输出打印    console.log(chunck);   //Buffer    //console.log(chunck.toString());  //转为String    process.nextTick(next)};writable.write(‘Happy Chinese Year‘);writable.end();

const objectModeWritable = Writable({ objectMode: true });objectModeWritable._write = (chunck, enc, next) => {    // 输出打印    console.log(typeof chunck);    console.log(chunck);    process.nextTick(next)};objectModeWritable.write(‘Happy Chinese Year‘);objectModeWritable.write( { year : 2017 } );objectModeWritable.end( 2017 );

var Readable = require(‘stream‘).Readable || require(‘readable-stream‘).Readable

//demo9const fs = require(‘fs‘);const through2 = require(‘through2‘);fs.createReadStream(‘data.txt‘)    .pipe(through2(function (chunk, enc, callback) {        for (var i = 0; i < chunk.length; i++)            if (chunk[i] == 97)                chunk[i] = 122; // 把 ‘a‘ 替换为 ‘z‘        this.push(chunk);        callback()    }))    .pipe(fs.createWriteStream(‘out.txt‘))    .on(‘finish‘, ()=> {        console.log(‘DONE‘)    });

//demo10const fs = require(‘fs‘);const through2 = require(‘through2‘);const csv2 = require(‘csv2‘);let all = [];fs.createReadStream(‘list.csv‘)    .pipe(csv2())    // through2.obj(fn) 是 through2({ objectMode: true }, fn) 的简易封装    .pipe(through2.obj(function (chunk, enc, callback) {        var data =http://www.mamicode.com/ {            name: chunk[0],            sex: chunk[1],            addr: chunk[2]        };        this.push(data);        callback()    }))    .on(‘data‘, function (data) {        all.push(data)    })    .on(‘end‘, function () {        console.log(all)    });