Getting binary content in node.js with http.reques

问题:

I would like to retrieve binary data from an https request.

I found a similar question that uses the request method, Getting binary content in Node.js using request, is says setting encoding to null should work, but it doesn't.

options = {
    hostname: urloptions.hostname,
    path: urloptions.path,
    method: 'GET',
    rejectUnauthorized: false,
    encoding: null
};

req = https.request(options, function(res) {
    var data;
    data = "";
    res.on('data', function(chunk) {
        return data += chunk;
    });
    res.on('end', function() {
        return loadFile(data);
    });
    res.on('error', function(err) {
        console.log("Error during HTTP request");
        console.log(err.message);
    });
})

Edit: setting encoding to 'binary' doesn't work either

回答1:

The accepted answer did not work for me (i.e., setting encoding to binary), even the user who asked the question mentioned it did not work.

Here's what worked for me, taken from: http://chad.pantherdev.com/node-js-binary-http-streams/

http.get(url.parse('http://myserver.com:9999/package'), function(res) {
    var data = [];

    res.on('data', function(chunk) {
        data.push(chunk);
    }).on('end', function() {
        //at this point data is an array of Buffers
        //so Buffer.concat() can make us a new Buffer
        //of all of them together
        var buffer = Buffer.concat(data);
        console.log(buffer.toString('base64'));
    });
});

Edit: Update answer following a suggestion by Semicolon

回答2:

You need to set encoding to response, not request:

req = https.request(options, function(res) {
    res.setEncoding('binary');

    var data = [ ];

    res.on('data', function(chunk) {
        data.push(chunk);
    });
    res.on('end', function() {
        var binary = Buffer.concat(data);
        // binary is your data
    });
    res.on('error', function(err) {
        console.log("Error during HTTP request");
        console.log(err.message);
    });
});

Here is useful answer: Writing image to local server

回答3:

Running on NodeJS 6.10 in the AWS Lambda environment, none of the solutions above worker for me.

What did work for me was the following:

https.get(opt, (res) => {
    res.setEncoding('binary');
    let chunks = [];

    res.on('data', (chunk) => {
        chunks.push(Buffer.from(chunk, 'binary'));
    });

    res.on('end', () => {
        let binary = Buffer.concat(chunks);
        // binary is now a Buffer that can be used as Uint8Array or as
        // any other TypedArray for data processing in NodeJS or 
        // passed on via the Buffer to something else.
    });
});

Take note the res.setEncoding('binary'); and Buffer.from(chunk, 'binary') lines. One sets the response encoding and the other creates a Buffer object from the string provided in the encoding specified previously.