Question

我正在使用nodejs来构建一个应用程序，该应用程序使用一些外部API，它返回以deflate格式压缩的json数据，但由于我是nodejs的新手，所以我查看了zlib api但是没有找到解码字符串的方法，请任何人帮助我，这是我的解码字符串：

u�O��0\u0010ſJ�CN4��?RT���ޫʚ�\u0001����f)]��wذڪ�r��7�͓�W�\u0003���?_�\u0005T����\tT����\u000f����y=��cu\u0012��\u000e����A��,5�\u0005\u0017ER�\u0011�^�8\rvE��0x��\u0000>��*�jTRA�\\SQe)/�d�����C�<?�4��4\u0007\b�\u001a��`(��@Y��\u0011{���-j���ք�\u0013� ^Y��T��\u001f��\u0010y�\u001a���=v�\'"�ʒGl��dX\'*��ӞR�b;��Y^���؂\u0017O{��\u001b��\u000fa��\u0018\u0014��8")\u0006m�\u001f�\u0007h����\u000ev96v�7G\u001f�vw��\t��J�i�U\u001a\u0018�(�7����Nζz@�G�p��iȲ,���\u000b\u0004po3��\u0018���\'i�`�(�S�]��P�Eˋ\u0013���\\�\u0007u�\nMЍ5\u0007w~�qhϜ�~E�\u0007OKp\u001f���l\u0003�\u0011~o\u000b����p\u0004m��X]�Uu�\u000b

Answer 1

不使用任何第三方库，也不试图检测服务器的编码：

void MainWindow::createPushButtons()
{
    QWidget * wdg = new QWidget(this);//--> widget contains pushButtons
    wdg->setObjectName("buttonWidget");//--> I set object name in order to catch widget and pushButtons in PaintEvent()
    setCentralWidget(wdg);//--> I add widget to app main layout

    for(int i=0; i<colors.size(); i++)//--> Button count and color count must be same.
    {
        QPushButton *btn = new QPushButton(QString::number(i)+". button",wdg);//--> create pushButtons in parent wdg
        btn->setGeometry(firstButtonX + (buttonWidth+triangleWidth)*i, firstButtonY, buttonWidth, buttonHeight);//--> I set geometry for pushButtons 

        btn->setStyleSheet(QString("background-color: %1;border-style: outset;border-width: 0px;").arg(colors.at(i).name()));//--> I change background color and clear border
    }
}

void MainWindow::paintEvent(QPaintEvent *event)
{
    QWidget *wdg = findChild<QWidget *>("buttonWidget");//--> I catch my widget
    QList<QPushButton *> buttons = wdg->findChildren < QPushButton *>();//--> I find pushButtons

    for(int i=0;i < buttons.size(); i++)
    {
        int x = buttons.at(i)->pos().x();//--> measurements for triangle
        int y = buttons.at(i)->pos().y();
        int w = buttons.at(i)->width();
        int h = buttons.at(i)->height();

        QRect r(x+w,y,triangleWidth,h);//--> I create rectangular area between pushButtons

        QPainter painter(this);
        qreal point3X = x+w + triangleWidth;//--> triangle corners
        qreal point3Y = y + h/2 ;
        qreal point1X = x+w;
        qreal point1Y = y;
        qreal point2X = x+w;
        qreal point2Y = y+h;

        QPainterPath path;
        path.moveTo (point1X, point1Y);
        path.lineTo (point2X, point2Y);
        path.lineTo (point3X, point3Y);

        painter.setPen (Qt :: NoPen);
        if(i != buttons.size()-1)//--> I paint rectangular and triangle
        {
            painter.fillRect(r, QBrush (colors.at(i+1)));
        }
        painter.fillPath (path, QBrush (colors.at(i)));
    }
}

标准zlib库也提供其他流处理程序，例如var options = { hostname: 'www.example.com', port: 80, path: '/deflateable-thing', method: 'GET' }; var req = http.request(options, function(res) { deflate = zlib.createDeflate(); res.pipe(deflate); deflate.on('data', function (chunk) { console.log('data: ' + chunk.toString()); }); }); req.end();。

Answer 2

嗯......首先你需要知道...... API是否产生Raw-Deflate或Deflate。此外，在放气时可以做出许多不同的选择。您必须了解Deflation时使用的配置。我假设您应该能够在您正在使用的API文档中找到它们。

让我们假设API现在正在使用默认设置（https://nodejs.org/api/zlib.html#zlib_options）生成Deflate。

现在...

var zlib = require( 'zlib' );

// lets assume you have your response from api in a string variable
var responseDeflateString = "response from api";
// convert it to a buffer ( as you provided, its a utf8 string)
var responseDeflateBuffer = new Buffer( responseDeflateString );
// now inflate the buffer
// Note 1 : zlib.inflateSync takes another argument "option" and this will
//          depend upon how this API service was deflating, and should be added 
//          based on API documentation. For now we are using default options.
// Note 2 : its better to use the asynchronous version. But we are using
//          synchronous one for the sake of simplicity.
var responseInflateBuffer = zlib.inflateSync( responseDeflateBuffer );
// decode the buffer back to string ( utf8 )
var responseInflateString = responseInflateBuffer.toString();

Answer 3

Request支持gzip参数。查看请求examples

var request = require('request')
  request(
    { method: 'GET'
    , uri: 'http://www.google.com'
    , gzip: true
    }
  , function (error, response, body) {
      // body is the decompressed response body
      console.log('server encoded the data as: ' + (response.headers['content-encoding'] || 'identity'))
      console.log('the decoded data is: ' + body)
    }
  )
  .on('data', function(data) {
    // decompressed data as it is received
    console.log('decoded chunk: ' + data)
  })
  .on('response', function(response) {
    // unmodified http.IncomingMessage object
    response.on('data', function(data) {
      // compressed data as it is received
      console.log('received ' + data.length + ' bytes of compressed data')
    })
  })

如何解码nodejs中的deflate字符串？

3 个答案: