Question

我正在使用NodeJs（w / express），我正在尝试将zip文件流回客户端。 zip中包含的文件不在文件系统上，而是动态创建。我想将文件内容流式传输到zip并将zip流式传输回客户端。

即。我希望客户收到：

tmp.zip
 --> 1.txt
 --> 2.txt
 --> 3.txt

其中1,2,3.txt即时创建并流式传输到zip文件。这可能吗？

Answer 1

Archiver有一个append方法，可以将文本另存为文件。到＆＃34;流＆＃34;您可以将数据传递给HTTP响应对象。

var Http = require('http');
var Archiver = require('archiver');

Http.createServer(function (request, response) {
    // Tell the browser that this is a zip file.
    response.writeHead(200, {
        'Content-Type': 'application/zip',
        'Content-disposition': 'attachment; filename=myFile.zip'
    });

    var zip = Archiver('zip');

    // Send the file to the page output.
    zip.pipe(response);

    // Create zip with some files. Two dynamic, one static. Put #2 in a sub folder.
    zip.append('Some text to go in file 1.', { name: '1.txt' })
        .append('Some text to go in file 2. I go in a folder!', { name: 'somefolder/2.txt' })
        .file('staticFiles/3.txt', { name: '3.txt' })
        .finalize();

}).listen(process.env.PORT);

这将创建一个包含两个文本文件的zip文件。访问此页面的用户将看到文件下载提示。

Answer 2

解决方案： express.js，wait.for，zip-stream

app.get('/api/box/:box/:key/download', function (req, res) {

    var wait = require('wait.for');

    var items = wait.for(function (next) {
        BoxItem.find({box: req.Box}).exec(next)
    });

    res.set('Content-Type', 'application/zip');
    res.set('Content-Disposition', 'attachment; filename=' + req.Box.id + '.zip');

    var ZipStream = require('zip-stream');
    var zip = new ZipStream();

    zip.on('error', function (err) {
        throw err;
    });

    zip.pipe(res);

    items.forEach(function (item) {

        wait.for(function (next) {

            var path = storage.getItemPath(req.Box, item);
            var source = require('fs').createReadStream(path);

            zip.entry(source, { name: item.name }, next);
        })

    });

    zip.finalize();

});

Answer 3

是的，这是可能的。我建议您查看Streams Playground以了解Node Streams的工作方式。

核心zlib库中的zip压缩似乎不支持多个文件。如果你想使用tar-gzip，可以使用node-tar进行tar。但如果你想要ZIP，adm-zip看起来是最好的选择。另一种可能性是node-archiver。

<强>更新

此example显示了如何使用支持流的Archiver。只需将fs.createReadStream替换为您动态创建的流，并将output流式传输到Express的res而不是fs.createWriteStream。

var fs = require('fs');

var archiver = require('archiver');

var output = fs.createWriteStream(__dirname + '/example-output.zip');
var archive = archiver('zip');

output.on('close', function() {
  console.log('archiver has been finalized and the output file descriptor has closed.');
});

archive.on('error', function(err) {
  throw err;
});

archive.pipe(output);

var file1 = __dirname + '/fixtures/file1.txt';
var file2 = __dirname + '/fixtures/file2.txt';

archive
  .append(fs.createReadStream(file1), { name: 'file1.txt' })
  .append(fs.createReadStream(file2), { name: 'file2.txt' });

archive.finalize(function(err, bytes) {
  if (err) {
    throw err;
  }

  console.log(bytes + ' total bytes');
});

Answer 4

使用expressjs和node-zip将zip文件作为二进制数据发送：

app.get("/multipleinzip", (req, res) => {
    var zip = new require('node-zip')();
    var csv1 = "a,b,c,d,e,f,g,h\n1,2,3,4,5,6,7,8\n1,2,3,4,5,6,7,8\n1,2,3,4,5,6,7,8\n1,2,3,4,5,6,7,8";
    zip.file('test1.file', csv1);
    var csv2 = "z,w,x,d,e,f,g,h\n1,2,3,4,5,6,7,8\n1,2,3,4,5,6,7,8\n1,2,3,4,5,6,7,8\n1,2,3,4,5,6,7,8";
    zip.file('test2.file', csv2);
    var csv3 = "q,w,e,d,e,f,g,h\n1,2,3,4,5,6,7,8\n1,2,3,4,5,6,7,8\n1,2,3,4,5,6,7,8\n1,2,3,4,5,6,7,8";
    zip.file('test3.file', csv3);
    var csv4 = "t,y,u,d,e,f,g,h\n1,2,3,4,5,6,7,8\n1,2,3,4,5,6,7,8\n1,2,3,4,5,6,7,8\n1,2,3,4,5,6,7,8";
    zip.file('test4.file', csv4);
    var data = zip.generate({base64:false,compression:'DEFLATE'});
    console.log(data); // ugly data
    res.type("zip")
    res.send(new Buffer(data, 'binary'));
})

为zip文件创建下载链接。使用->

获取数据并将响应转换为arraybuffer

    //get the response from fetch as arrayBuffer...
    var data = response.arrayBuffer();

    const blob = new Blob([data]);
    const fileName = `${filename}.${extension}`;
    
    if (navigator.msSaveBlob) {
      // IE 10+
      navigator.msSaveBlob(blob, fileName);
    } else {
      const link = document.createElement('a');
      // Browsers that support HTML5 download attribute
      if (link.download !== undefined) {
        const url = URL.createObjectURL(blob);
        link.setAttribute('href', url);
        link.setAttribute('download', fileName);
        link.style.visibility = 'hidden';
        document.body.appendChild(link);
        link.click();
        document.body.removeChild(link);
      }
    }

动态创建zip并将其流式传输到客户端

4 个答案: