server responded with a status of 404 (Not Found): mean stack & ionic - ionic2

Question

I making a request to the back-end server of the port number 8000. I'm making request from the android emulator. so, instead of localhost i'm using ip address. It is throwing the error as
Failed to load resource: the
http://192.168.0.102:8000/api/facebookuser server responded with a
status of 404 (Not Found)
This is my code
postFacebookData(userdata) {
alert(userdata);
let headers = new HttpHeaders();
headers.append('Content-Type','application/json');
return this.http.post('http://192.168.0.102:8000/api/facebookuser',userdata,{headers: headers})
}
This is from routes file
router.post('/facebookuser', function(req,res) {
console.log('facebook request');
It is not subscribing to the method
this.fbPage.postFacebookData(userData)
.subscribe((data: any) => {
if (data.success) {
alert('Data added sucessfully ' && data.msg);
this.authservices.storeUserData(data.token,data.user);
this.navCtrl.push(EditinfoPage);
}
else {
alert('data is not added');
}
},(err) => {
alert('error in subscribing ' + err);
I'm getting an error message in the cosole from the above code as
error in subscribing [object object]

Answer 1

The error is indicating, that the request cannot find the resource you are trying to request.
Make sure that the IP-Adress for your backend is correct (using ipconfig for instance)
Make sure that the endpoint "api/facebookuser" is correct
Make sure that the EMULATOR is in the same network (e.g. WLAN) than your computer (assuming that the backend is running on localhost)