Java Servlet Backend "http://localhost:8080 connection refused" error
Cris Benois via StackOverflow
I am adding a "App Engine Java Servlet Module" Template as a backend to my app, so I am performing an HTTP request:
class ServletPostAsyncTask extends AsyncTask<Pair<Context, String>, Void, String> {
private Context context;
@Override
protected String doInBackground(Pair<Context, String>... params) {
context = params[0].first;
String name = params[0].second;
HttpClient httpClient = new DefaultHttpClient();
HttpPost httpPost = new HttpPost("http://10.0.2.2:8080/hello");
// http://10.0.2.2:8080 is localhost's IP address in Android emulator
try {
// Add name data to request
List<NameValuePair> nameValuePairs = new ArrayList<NameValuePair>(1);
nameValuePairs.add(new BasicNameValuePair("name", name));
httpPost.setEntity(new UrlEncodedFormEntity(nameValuePairs));
// Execute HTTP Post Request
HttpResponse response = httpClient.execute(httpPost);
if (response.getStatusLine().getStatusCode() == 200) {
return EntityUtils.toString(response.getEntity());
}
return "Error: " + response.getStatusLine().getStatusCode() + " " + response.getStatusLine().getReasonPhrase();
} catch (ClientProtocolException e) {
return e.getMessage();
} catch (IOException e) {
return e.getMessage();
}
}
@Override
protected void onPostExecute(String result) {
Toast.makeText(context, result, Toast.LENGTH_LONG).show();
}
}
The problem is that when I execute I get this error: http://10.0.2.2:8080 connection refused
I already tried for several solutions:
- I already have <uses-permission android:name="android.permission.INTERNET" /> in my manifest file
- I know that 10.0.2.2 is the equivalent of 127.0.0.1 when I use the emulator, in fact this code works within my emulator but doesn't within my physical device
- I've tried with http://localhost:8080 but still, same error
Reading around I learned that localhost corresponds to the hostname of my device, not of the machine where the Servlet is, but really then, I have no clue on what the address could be!
I've also tried with my machine's IP address, but in this case I don't get any Toast message, wheter error or not, just nothing pops out... could this be a hint?
I would really appreciate your backup.
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http://stackoverflow.com/questions/29040353/java-servlet-backend-http-localhost8080-connection-refused-error
Cris Benois via StackOverflow
I already tried several solutions:
- I already have
<uses-permission android:name="android.permission.INTERNET" />in my manifest file
- I know that 10.0.2.2 is the equivalent of 127.0.0.1 when I use the emulator, in fact this code works within my emulator but doesn't within my physical device
- I've tried with http://localhost:8080 but still, same error
Reading around I learned that localhost corresponds to the hostname of my device, not of the machine where the Servlet is, but then I have no clue on what the address could be.
I've also tried with my machine's IP address, but in this case I don't get any Toast message, wheter error or not, just nothing pops out... could this be a hint?
I would really appreciate your backup here.
Robert Moskal via StackOverflow
Check to make sure you are making a post request. That's what the servlet is set up to listen for.
It's not so easy to make one from the browser.
Please DO NOT REPLY directly to this email but go to StackOverflow: