Develop Reference

Android: HttpUrlConnection object returns error 301 after connection

I'm trying to connect to a web API using a URL. However, I get a 301 error from the server (Moved Permanently), although the provided URL works very well with no errors when I try it in my browser.
Here is the code that builds the URL:
public Loader<List<Earthquake>> onCreateLoader(int i, Bundle bundle) {
SharedPreferences sharedPrefs = PreferenceManager.getDefaultSharedPreferences(this);
String minMagnitude = sharedPrefs.getString(
getString(R.string.settings_min_magnitude_key),
getString(R.string.settings_min_magnitude_default));
String orderBy = sharedPrefs.getString(
getString(R.string.settings_order_by_key),
getString(R.string.settings_order_by_default)
);
Uri baseUri = Uri.parse(USGS_REQUEST_URL);
Uri.Builder uriBuilder = baseUri.buildUpon();
uriBuilder.appendQueryParameter("format", "geojson");
uriBuilder.appendQueryParameter("limit", "10");
uriBuilder.appendQueryParameter("minmag", minMagnitude);
uriBuilder.appendQueryParameter("orderby", orderBy);
Log.i ("the uri is ", uriBuilder.toString());
return new EarthquakeLoader(this, uriBuilder.toString());
}
Here is the code that tries to connect to the resource represented by the URL:
private static String makeHttpRequest(URL url) throws IOException {
String jsonResponse = "";
// If the URL is null, then return early.
if (url == null) {
return jsonResponse;
}
Log.i("The received url is " , url +"");
HttpURLConnection urlConnection = null;
InputStream inputStream = null;
try {
urlConnection = (HttpURLConnection) url.openConnection();
urlConnection.setReadTimeout(10000 /* milliseconds */);
urlConnection.setConnectTimeout(15000 /* milliseconds */);
urlConnection.setRequestMethod("GET");
urlConnection.connect();
// If the request was successful (response code 200),
// then read the input stream and parse the response.
if (urlConnection.getResponseCode() == 200) {
inputStream = urlConnection.getInputStream();
jsonResponse = readFromStream(inputStream);
} else {
Log.e(LOG_TAG, "Error response code: " + urlConnection.getResponseCode()); //this log returns 301
}
} catch (IOException e) {
Log.e(LOG_TAG, "Problem retrieving the earthquake JSON results.", e);
} finally {
if (urlConnection != null) {
urlConnection.disconnect();
}
if (inputStream != null) {
// Closing the input stream could throw an IOException, which is why
// the makeHttpRequest(URL url) method signature specifies than an IOException
// could be thrown.
inputStream.close();
}
}
return jsonResponse;
}
I could know that the connection returns status code of 301 from the log provided in the case when the status code is not 200. I have also logged the generated URL, I copied it from the logcat and tried it in my browser and it worked well. Here is the built URL: http://earthquake.usgs.gov/fdsnws/event/1/query?format=geojson&limit=10&minmag=6&orderby=magnitude
I checked this question: Android HttpURLConnection receives HTTP 301 response code but it wasn't clear to me what is the solution for the problem.
Can you please help me identify and solve the problem?
UPDATE: As greenapps indicated in his comment, the connection is done through https. That comment identified the problem and helped me fix the code.
In my code, the string I used to build the basic URL, had the protocol value as http not https, it was:
private static final String USGS_REQUEST_URL =
"http://earthquake.usgs.gov/fdsnws/event/1/query";
After reading greenapps comment, I just changed the protocol part in the string to https, so it became:
private static final String USGS_REQUEST_URL =
"https://earthquake.usgs.gov/fdsnws/event/1/query";
That solved the problem.
Thanks.

If you click your http link here you will see that the browser shows a https page. You better use that url directly as there is redirection now.

This is because the address http to https transferred.
To avoid this, you need to convert the request address to https.

Why dont open weather map api return data in android app?

I am trying to fetch JSON data from open weather map api with following code but it always gets fail. I dont know what exception happens and I always get null response as defined in the catch.
try {
//URL url = new URL(String.format(OPEN_WEATHER_MAP_API, city));
URL url = new URL(String.format(OPEN_WEATHER_MAP_API));
HttpURLConnection connection =
(HttpURLConnection)url.openConnection();
connection.addRequestProperty("x-api-key",
context.getString(R.string.open_weather_maps_app_id));
BufferedReader reader = new BufferedReader(
new InputStreamReader(connection.getInputStream()));
StringBuffer json = new StringBuffer(1024);
String tmp="";
while((tmp=reader.readLine())!=null)
json.append(tmp).append("\n");
reader.close();
JSONObject data = new JSONObject(json.toString());
// This value will be 404 if the request was not
// successful
if(data.getInt("cod") != 200){
return null;
}
return data;
}catch(Exception e){
return null;
}

Without, knowing how you are creating your URL, it looks like you are missing the city in your String.format
URL url = new URL(String.format(OPEN_WEATHER_MAP_API));
Shouldn't it be
URL url = new URL(String.format(OPEN_WEATHER_MAP_API, city));

I'm commenting here as I don't have privilege to comment in your question thread.
Print stack trace of your catch block, you may be able to find solution to your problem.

I had to add the following permission along with internet permission.
<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />

what URL you have assigned to your OPEN_WEATHER_MAP_API..?
url should be- http://api.openweathermap.org/data/2.5/weather?q=city&units=metric
please try this...

URL Malformed Exception error in Android (java.net.MalformedURLException: Protocol not found)

One of my URL is like the following: "h--p://www.test.com///rss.xml"
When I run the following code:
private String RSSFEEDURL = Uri.encode("h--p://www.test.com/path/*/*/rss.xml");
URL url = null;
try {
url = new URL(xml);
} catch (MalformedURLException e1) {
e1.printStackTrace();
}
I am getting "java.net.MalformedURLException: Protocol not found: http%3A%2F%2Ftest.com%2Fpath%2F*%2F*%2Frss.xml"
I have already done Uri encode as shown above. Any idea, what is causing this issue and how I could resolve it?

if you call new URL the thing you put in there should be a valid URL.
You're putting this in there: http%3A%2F%2Ftest.com%2Fpath%2F*%2F*%2Frss.xml, and that's not a valid URL, so the exception is expected.
You shouldn't encode your whole URL.

Android: HttpURLConnection redirect - doInBackground

I'm using HttpURLConnection to do communication with a backend server and im doing so in an async task in the doInBackground method as you should.
Now I need to be able to follow 302 redirects, but I'm having some problems with this. The issue is that the new location usually will be on another host, however when doing the redirect request it seem not to change the URL to a new host hence I get a 404 error saying the specified path does not exits.
Now I know I could set HtppURLConnection.setFollowRedirect but I need to have more control over the redirects so they should not just be followed blindly. The Redirect behavour should be controlled by the object who called the asynctask (when an asynctask object is created you pass the object who creates it in a parameter called _callback).
Heres's my current code:
protected HttpResponse doInBackground(String... req) {
HttpURLConnection urlConnection = null;
try {
urlConnection = (HttpURLConnection) this._url.openConnection();
urlConnection.setConnectTimeout( (int) this._timeout*1000);
String body = req[0];
// set headers / write information to output stream if request is post
// create the response object
HttpResponse responseObject = null;
try
{
// get status, contenttype, charset...
InputStream in = null;
if (urlConnection.getResponseCode() != -1 && urlConnection.getResponseCode() < 300)
{
in = new BufferedInputStream(urlConnection.getInputStream(), 8192);
}
else
{
in = new BufferedInputStream(urlConnection.getErrorStream(), 8192);
}
responseObject = new HttpResponse(in, status, contentType, charset);
// if redirect
if (status == 302 && this._callback.onRedirect(responseObject) == true)
{
// recall
String url = urlConnection.getHeaderField("location");
Log.v("Async Task", "Redirect location: " + url);
this._url = null;
this._url = new URL(url);
urlConnection.disconnect();
urlConnection = null;
responseObject = this.doInBackground(req);
}
} catch (IOException e)
{
// TODO Auto-generated catch block
e.printStackTrace();
}
// return the response
return responseObject;
}
// catch some other exceptions
finally
{
if (urlConnection != null)
{
urlConnection.disconnect();
} }
}
And as said the problem is that the redirect request seem to change the path of the URL but not the host. The URL object itself seem to contain the right information so I have no idea why this is happening. (I'm getting HTML as response which is an 404 error page that includes the server name of the old server)
Thanks for any help!
Note: HttpResponse is just an object I created for holding the relevant information about the response.

This was caused by the fact that I sent the same headers and did not change the "host" header of the request which caused Apache to be confused it seems.

Android InputStream following a rewriterule

I'm trying to parse an xml file from a website. Let's say the website is "http://example.com"
This website has a htaccess rewrite rule setup to redirect anything with a "www" prefix to the host back to example.com. so "http://www.example.com" would redirect to "http://example.com"
In my code I have a URL that i get the InputStream of.
protected InputStream getInputStream() {
try {
return feedUrl.openConnection().getInputStream();
} catch (IOException e) {
throw new RuntimeException(e);
}
}
In this case feedUrl is poingting to "http://www.example.com/file.xml" and when I do the following:
try {
Xml.parse(this.getInputStream(), Xml.Encoding.UTF_8, root.getContentHandler());
} catch (Exception e) {
throw new RuntimeException(e);
}
I get an exception thrown and I believe it's not redirecting to "http://example.com/file.xml"
I could obviously just statically change where my feedUrl variable is pointing to, but I need this to be dynamic.

If anyone ran into this problem like I did, then here's the solution. The HttpURLConnection is already setup to follow redirects by default if the response code is 300, 301, 302, or 303.
For some reason, the server I'm parsing from needs to have the response code be 307 which Android does not redirect automatically.
I would suggest using a different response code, but if your server needs it then here's work around.
HttpURLConnection conn = (HttpURLConnection) feedUrl.openConnection();
int responseCode = conn.getResponseCode();
if( responseCode == 307 ){
String location = conn.getHeaderField("location");
feedUrl = new URL(location);
conn = (HttpURLConnection) this.feedUrl.openConnection();
}
Now conn can open an input stream to the correct file.