Sending multiple JSON request to server under one request nodejs - json

Question

I have some files downloaded and I wanna push them to a server. Every time I try to push the file I get the error
Error: Can't set headers after they are sent.
I have a for loop that reads all the files and parse them and after that I want to send them to the server one by one.
app.get('/dataparser', function(req, res) {
var fs = require('fs');
var obj;
var jsonGis = new Array();
var jsonArray;
var filePaths = [];
const downloadFolder = './sampletest/';
var mtimes = {};
var reloadTimes = 10000;
fs.readdir(downloadFolder, (err, files) => {
files.forEach(file => {
filePaths.push("sampletest/" + file);
});
})
var execFunction = function() {
for (var i = 0; i < filePaths.length; i++) {
parseFile(filePaths[i], mtimes[filePaths[i]]);
}
};
execFunction();
setInterval(execFunction, reloadTimes);
function parseFile(fileName, lastModifiedTime) {
fs.stat(fileName, function(err, fd) {
for (var i=0, len = filePaths.length; i<len; i++) {
if (fd.mtime !== lastModifiedTime) {
mtimes[fileName] = fd.mtime;
fs.readFile(filePaths[i], function(err, data) {
if (err) {
return console.error(err);
}
obj = JSON.parse(data);
jsonGis.push('"Person1"');
jsonGis.push('"' + obj.pages[1].answers[2].values[0] + '"');
jsonGis.push('"person2"');
jsonGis.push('"' + obj.pages[1].answers[0].values[0] + '"');
jsonGis.push('"codewals"');
jsonGis.push('"42343GSDS"');
jsonGis.push('"geometry":{');
jsonGis.push('"x":' + obj.pages[1].answers[4].values[0].coordinates.latitude + ',');
jsonGis.push('"y":' + obj.pages[1].answers[4].values[0].coordinates.longitude);
var str = "[{ " + jsonGis[0] + jsonGis[1] + jsonGis[2] + ": " + jsonGis[3] + "," + jsonGis[4] + ": " + jsonGis[16] + "}}]"
//pushing to the server
console.log("check here");
console.log(str);
var qs = require("querystring");
var http = require("http");
var options = {
"method": "POST",
"hostname": "twst2.gtw.com",
"port": null,
"path": "localpath/",
"headers": {
"accept": "application/json",
"content-type": "application/x-www-form-urlencoded",
}
};
var req = http.request(options, function(res) {
var chunks = [];
res.on("data", function(chunk) {
chunks.push(chunk);
});
res.on("end", function() {
var body = Buffer.concat(chunks);
console.log(body.toString());
});
});
req.write(qs.stringify({features: str}));
res.send("The server was updated");
req.end();
});
}
}
});
};
Just need to send the data to the server from file1.json and then file2.json then file3.json and so on.

Answer 1

Try creating a separate callback function that includes .write, .send, and .end, then let it be the callback for .request.