This post describes how to use Android Openweathermap API to build an Android weather app that gives current weather information. This full guide covers all the aspects you need to know to build an Android weather app. During this guide you will learn:

  • How to use Openweathermap API
  • How to parse JSON data
  • How to make HTTP requests in Android
  • How to create an Android UI

As weather provider, this Android weather app will use OpenWeatherMap a free weather service that provides some interesting API really easy to use.

If you are interested on the Android app source code you can download it here:

The final result is shown below so that you can have an idea about what we will do in this post.

android openweathermap api

Android Openweathermap API Key

Before starting, it is necessary to get the API key we will use later. To get the API Key it is necessary to create your account.. Then login:

openweathermap api

Now click on API Keys in the menu in the top and get your key:

 

Openweathermap API Key for Android weather app

Now we can your our key to invoke the APIs

http://api.openweathermap.org/......&APPID={API_KEY}

In the tutorial below, we assume you have the API Key and you append it to the URL.

Android Openweathermap API: Current weather info

OpenWeatherMap offers several API to use to get weather information. This Android weather app uses the Openweathermap API that gives us the current weather info.

The URL to call to get this info is:

http://api.openweathermap.org/data/2.5/weather?q=city,country&APPID={your_key}

Let’s suppose we want to know the weather in Rome, IT. Using our browser we can have:

weather api search
As we can see we have JSON response. Formatting the response we have

[json]{
  "coord": {
    "lon": 12.48,
    "lat": 41.89
  },
  "weather": [
    {
      "id": 800,
      "main": "Clear",
      "description": "clear sky",
      "icon": "01d"
    }
  ],
  "base": "stations",
  "main": {
    "temp": 278.71,
    "pressure": 1023,
    "humidity": 48,
    "temp_min": 277.15,
    "temp_max": 280.15
  },
  "visibility": 10000,
  "wind": {
    "speed": 7.7,
    "deg": 350
  },
  "clouds": {
    "all": 0
  },
  "dt": 1546509000,
  "sys": {
    "type": 1,
    "id": 6792,
    "message": 0.0447,
    "country": "IT",
    "sunrise": 1546497475,
    "sunset": 1546530690
  },
  "id": 6539761,
  "name": "Rome",
  "cod": 200
}
[/json]

Parsing Openweathermap JSON Data

The first thing we need to do is creating our data model so that we can parse the response and convert it into Java classes. Analyzing the response we have different “main” tags that we can use as classes in Java:

  • coord (object)
  • weather (array)
  • main (object)
  • wind (object)
  • name: (String)
  • sys: (Object)

The response is quite simple and we can parse it manually. The UML class diagram for the model is shown below:

[bctt tweet=”The definitive guide to build a weather app in Android.”]

weather uml model

Android JSON Weather Parser

Once we have created our model we have to parse it. We can create a specific class that handles this task. First, we have to create the “root” object that receives as input the entire string containing all the JSON response:

// We create out JSONObject from the data
JSONObject jObj = new JSONObject(data);

Then we start parsing each piece of the response:

// We start extracting the info
Location loc = new Location();

JSONObject coordObj = getObject("coord", jObj);
loc.setLatitude(getFloat("lat", coordObj));
loc.setLongitude(getFloat("lon", coordObj));

JSONObject sysObj = getObject("sys", jObj);
loc.setCountry(getString("country", sysObj));
loc.setSunrise(getInt("sunrise", sysObj));
loc.setSunset(getInt("sunset", sysObj));
loc.setCity(getString("name", jObj));
weather.location = loc;

In the line 4,8 we create two “sub” object (coordObj and sysObj) having as parent the jObj as it clear from the JSON response. As we can see we use some helper methods to get String, int and float values:

private static JSONObject getObject(String tagName, JSONObject jObj) throws JSONException {
  JSONObject subObj = jObj.getJSONObject(tagName);
  return subObj;
}

private static String getString(String tagName, JSONObject jObj) throws JSONException {
  return jObj.getString(tagName);
}

private static float getFloat(String tagName, JSONObject jObj) throws JSONException {
  return (float) jObj.getDouble(tagName);
}

private static int getInt(String tagName, JSONObject jObj) throws JSONException {
 return jObj.getInt(tagName);
}

And then we finally parse the weather information. We have to remember that weather tag is an array so we have to handle it differently

// We get weather info (This is an array)
JSONArray jArr = jObj.getJSONArray("weather");

// We use only the first value
JSONObject JSONWeather = jArr.getJSONObject(0);
weather.currentCondition.setWeatherId(getInt("id", JSONWeather));
weather.currentCondition.setDescr(getString("description", JSONWeather));
weather.currentCondition.setCondition(getString("main", JSONWeather));
weather.currentCondition.setIcon(getString("icon", JSONWeather));

JSONObject mainObj = getObject("main", jObj);
weather.currentCondition.setHumidity(getInt("humidity", mainObj));
weather.currentCondition.setPressure(getInt("pressure", mainObj));
weather.temperature.setMaxTemp(getFloat("temp_max", mainObj));
weather.temperature.setMinTemp(getFloat("temp_min", mainObj));
weather.temperature.setTemp(getFloat("temp", mainObj));

// Wind
JSONObject wObj = getObject("wind", jObj);
weather.wind.setSpeed(getFloat("speed", wObj));
weather.wind.setDeg(getFloat("deg", wObj));

// Clouds
JSONObject cObj = getObject("clouds", jObj);
weather.clouds.setPerc(getInt("all", cObj));

At the end, we have our Weather class filled with the data retrieved.

Android HTTP Request and Response

Now we have to exchange information between our android app and the remote server using HTTP protocol so that the app can invoke Android Openweathermap API. We have to send information and then read the response. We covered this topic in the previous post(Android HTTP Client: GET, POST, Download, Upload, Multipart Request) so we won’t describe it again, we simply show the code:

public class WeatherHttpClient {

private static String BASE_URL = "http://api.openweathermap.org/data/2.5/weather?q=";
private static String IMG_URL = "http://openweathermap.org/img/w/";
private static String APPID = "{your_key}";
public String getWeatherData(String location) {
  HttpURLConnection con = null ;
  InputStream is = null;

  try {
   con = (HttpURLConnection) ( new URL(BASE_URL + location + "&APPID=" + APPID)).openConnection();
   con.setRequestMethod("GET");
   con.setDoInput(true);
   con.setDoOutput(true);
   con.connect();

   // Let's read the response
   StringBuffer buffer = new StringBuffer();
   is = con.getInputStream();
   BufferedReader br = new BufferedReader(new InputStreamReader(is));
   String line = null;
   while ( (line = br.readLine()) != null )
     buffer.append(line + "rn");

   is.close();
   con.disconnect();
   return buffer.toString();
 }
 catch(Throwable t) {
  t.printStackTrace();
 }
 finally {
  try { is.close(); } catch(Throwable t) {}
  try { con.disconnect(); } catch(Throwable t) {}
 }

 return null;

}

public byte[] getImage(String code) {
  HttpURLConnection con = null ;
  InputStream is = null;
  try {
   con = (HttpURLConnection) ( new URL(IMG_URL + code)).openConnection();
   con.setRequestMethod("GET");
   con.setDoInput(true);
   con.setDoOutput(true);
   con.connect();

  // Let's read the response
  is = con.getInputStream();
  byte[] buffer = new byte[1024];
  ByteArrayOutputStream baos = new ByteArrayOutputStream();

  while ( is.read(buffer) != -1)
   baos.write(buffer);

   return baos.toByteArray();
  }
  catch(Throwable t) {
   t.printStackTrace();
  }
  finally {
   try { is.close(); } catch(Throwable t) {}
   try { con.disconnect(); } catch(Throwable t) {}
  }

  return null;

 }
}

Android Weather App

Finally, it is the time for our Activity. The layout is very simple and, of course, it is just a skeleton you need to improve it if you want to have a production app.

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:paddingBottom="@dimen/activity_vertical_margin"
android:paddingLeft="@dimen/activity_horizontal_margin"
android:paddingRight="@dimen/activity_horizontal_margin"
android:paddingTop="@dimen/activity_vertical_margin"
tools:context=".MainActivity" >

  <TextView
    android:id="@+id/cityText"
    style="?android:attr/textAppearanceMedium"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_centerHorizontal="true" />

  <ImageView
    android:id="@+id/condIcon"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_alignParentLeft="true"
    android:layout_below="@id/cityText" />

  <TextView
    android:id="@+id/condDescr"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_below="@id/condIcon"
    android:layout_alignLeft="@id/condIcon"
  />

  <TextView
    android:id="@+id/temp"
    style="@style/tempStyle"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_marginLeft="12dp"
    android:layout_alignBaseline="@id/condDescr"
    android:layout_toRightOf="@id/condDescr"/>

  <TextView
    android:id="@+id/pressLab"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_alignParentLeft="true"
    android:layout_below="@id/condDescr"
    android:text="Pressure"
    android:layout_marginTop="15dp" />

  <TextView
    android:id="@+id/press"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_alignBaseline="@id/pressLab"
    android:layout_toRightOf="@id/pressLab"
    style="@style/valData"/>

  <TextView
    android:id="@+id/humLab"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_alignParentLeft="true"
    android:layout_below="@id/pressLab"
    android:text="Humidity" />

  <TextView
    android:id="@+id/hum"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_alignBaseline="@id/humLab"
    android:layout_toRightOf="@id/humLab"
    android:layout_marginLeft="4dp"
    style="@style/valData"/>

  <TextView
    android:id="@+id/windLab"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_alignParentLeft="true"
    android:layout_below="@id/humLab"
    android:text="Wind" />

  <TextView
   android:id="@+id/windSpeed"
   android:layout_width="wrap_content"
   android:layout_height="wrap_content"
   android:layout_alignBaseline="@id/windLab"
   android:layout_toRightOf="@id/windLab"
   android:layout_marginLeft="4dp"
   style="@style/valData" />

  <TextView
   android:id="@+id/windDeg"
   android:layout_width="wrap_content"
   android:layout_height="wrap_content"
   android:layout_alignBaseline="@id/windLab"
   android:layout_toRightOf="@id/windSpeed"
   android:layout_marginLeft="4dp"
   style="@style/valData"/>

</RelativeLayout>

In onCreate method, we simply get the reference to the Views inside the layout so that we can populate them later after the request is completed.

@Override
protected void onCreate(Bundle savedInstanceState) {
  super.onCreate(savedInstanceState);
  setContentView(R.layout.activity_main);
  String city = "Rome,IT";

  cityText = (TextView) findViewById(R.id.cityText);
  condDescr = (TextView) findViewById(R.id.condDescr);
  temp = (TextView) findViewById(R.id.temp);
  hum = (TextView) findViewById(R.id.hum);
  press = (TextView) findViewById(R.id.press);
  windSpeed = (TextView) findViewById(R.id.windSpeed);
  windDeg = (TextView) findViewById(R.id.windDeg);
  imgView = (ImageView) findViewById(R.id.condIcon);

  JSONWeatherTask task = new JSONWeatherTask();
  task.execute(new String[]{city});
}

and we start an AsyncTask, because as we already know network operations are time-consuming so we can run them in the main thread otherwise we could have an ANR problem. The JSONWeatherTask is very simply

protected Weather doInBackground(String... params) {
  Weather weather = new Weather();
  String data = ( (new WeatherHttpClient()).getWeatherData(params[0]));

  try {
   weather = JSONWeatherParser.getWeather(data);

   // Let's retrieve the icon
   weather.iconData = ( (new WeatherHttpClient()).getImage(weather.currentCondition.getIcon()));

  } catch (JSONException e) {
    e.printStackTrace();
  }
  return weather;
}

At line 3 we make the HTTP request and then we parse it at line 6.

At line 9 we retrieve the icon that shows the weather condition.
Running the code we have:

weather android openweathermap
weather android app

It could be interesting to integrate a physical object using IoT project with weather forecast and Arduino.

Hopefully, at the end of this post, you gained the knowledge on how to implement an Android Openweathermap app that shows the current weather information.

100 COMMENTS

  1. When I enter "JSONObject coordObj = getObject("coord", jObj);" in the mainactivity I get the error: "Unhandled exception: org.json.JSON.exception". While the getObject method is also implemented and org.json.JSONException is imported.

  2. Thanks, great tutorial! Could you tell me how to use the forecast feature as well? For example displaying the 5 day forecast?

  3. Awesome job. How would you change the location though? I'm trying to make a weather app so I want to be able to change the location using the gps. Thanks in advance.

  4. You should get the gps location coord and then make a query using lat and long parameters. Check the openweathermap api for more information

  5. This tutorial is very helpful, but one problem I have is the weather icon doesn't show up. In the onPostExecute() method the if statement never runs. Do you have any idea why that's happening?

  6. As far as i know, there are some weather code that doesn't have an icon. You should map weather code with your icon weather set.

  7. I'm using your code exactly and it works great but icons don't show up. I can see the icons in your screenshots, can you give us the code you use?

  8. Hi, this is a great example, thanks for this.

    I just don't know for what purpose
    " con.setDoInput(true); -> Line 48
    con.setDoOutput(true); -> Line 49"

    these two lines are added, but when i removed these two lines weatherhttpclient, the icon showed up on the app. When these line are used the server is returning File Not Found Exception

  9. In Main activity i think the conversion to centigrade, needs to be "temp.setText("" + Math.round((weather.temperature.getTemp() – 273.15)) + "°C"); instead of "temp.setText("" + Math.round((weather.temperature.getTemp() – 275.15)) + "°C");

  10. setDoInput means that the app wants to use the connection as input, so it wants to read data. AFAIK the default value is true so if you remove it i guess the result doesn't change. setDoOutput means the app wants to write to the connection. The default value is false. In my experience this two parameters doesn't affect the icon download. If you look at my app in the app store it download icons correctly. Anyway i guess the problem happens when there's some weather code that doesn't match an icon. Let me know if you have an example that helps me.

  11. Great Tutorial Thanks! I was trying your example and I am getting an error while downloading the weather icons. I get the following exception

    12-19 00:15:39.049: W/System.err(1295): java.io.FileNotFoundException: http://openweathermap.org/img/w/01n

    when I type this url in the browser I am able to see the weather icon but in the android emulator this fails. Any idea?

  12. i'm getting null from this method :

    weather.iconData = ( (new WeatherHttpClient()).getImage(weather.currentCondition.getIcon()));

  13. Anyone knows why my location is always London instead Vicenza (Italy)? I tried to download the source and run the apk but always returns that i am in London.. Doesn't recognize the geolocation?

  14. In the tutorial source code, the geolocation is not implemented. If you look at line 59 of the MainActivity class you can notice there is:

    String city = "London,UK";

    for that it loads by default London weather condition. Hope it helps you.

  15. Ah ok.. because i really need the code with geolocation and i can't find anything on the web.. I need very little informations like only : condition and temperature nothing more. Of course using location. But actually i can't do it. Can i contact you via hangout?

  16. How can I create a "iconData" resource reference for new icons? I put in the line:

    if (weather.iconData != null && weather.iconData.length > 0){
    -> here I put the icon reference with if statement, am I right?
    }
    I appreciate any help

  17. I am hoping you can help, I get some user crashes on 4.4.2 on a few devices. Hoping you could point me in the right direction.

    I am using open weather, per your http client

    private static String BASE_URL = "http://api.openweathermap.org/data/2.5/weather?&quot;;

    "message" and "gust" are not part of you tutorial, but I do not get a crash on my devices even they return this. I am not familair with parse outside of your tutorial.

    Line 44

    JSONObject jObj = new JSONObject(data);

    Thanks

    On data, I get the following,

    WEATHER DATA

    {"coord":{"lon":-99.04,"lat":34.17},"sys":{"message":0.037,"country":"US","sunrise":1397218143,"sunset":1397264699},"weather":[{"id":800,"main":"Clear","description":"Sky is Clear","icon":"01n"}],"base":"cmc stations","main":{"temp":292.06,"pressure":1011,"temp_min":291.15,"temp_max":293.15,"humidity":31},"wind":{"speed":3.6,"gust":5.65,"deg":18},"clouds":{"all":0},"dt":1397188520,"id":4716202,"name":"Oklaunion","cod":200}

    java.lang.RuntimeException: An error occured while executing doInBackground()
    at android.os.AsyncTask$3.done(AsyncTask.java:300)
    at java.util.concurrent.FutureTask.finishCompletion(FutureTask.java:355)
    at java.util.concurrent.FutureTask.setException(FutureTask.java:222)
    at java.util.concurrent.FutureTask.run(FutureTask.java:242)
    at android.os.AsyncTask$SerialExecutor$1.run(AsyncTask.java:231)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1112)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:587)
    at java.lang.Thread.run(Thread.java:841)

    Caused by: java.lang.NullPointerException
    at org.json.JSONTokener.nextCleanInternal(JSONTokener.java:116)
    at org.json.JSONTokener.nextValue(JSONTokener.java:94)
    at org.json.JSONObject.(JSONObject.java:155)
    at org.json.JSONObject.(JSONObject.java:172)
    at com.survivingwithandroid.weatherapp.model.JSONWeatherParser.getWeather(JSONWeatherParser.java:44)

  18. My post was cutoff at the bottom

    java.lang.RuntimeException: An error occured while executing doInBackground()
    at android.os.AsyncTask$3.done(AsyncTask.java:300)
    at java.util.concurrent.FutureTask.finishCompletion(FutureTask.java:355)
    at java.util.concurrent.FutureTask.setException(FutureTask.java:222)
    at java.util.concurrent.FutureTask.run(FutureTask.java:242)
    at android.os.AsyncTask$SerialExecutor$1.run(AsyncTask.java:231)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1112)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:587)
    at java.lang.Thread.run(Thread.java:841)

    Caused by: java.lang.NullPointerException
    at org.json.JSONTokener.nextCleanInternal(JSONTokener.java:116)
    at org.json.JSONTokener.nextValue(JSONTokener.java:94)
    at org.json.JSONObject.(JSONObject.java:155)
    at org.json.JSONObject.(JSONObject.java:172)
    at com.survivingwithandroid.weatherapp.model.JSONWeatherParser.getWeather(JSONWeatherParser.java:44)
    atnet.RollMeOver.RollMeOver.RollMeOverActivity$JSONWeatherTask.doInBackground(RollMeOverActivity.java:3896)
    at net.RollMeOver.RollMeOver.RollMeOverActivity$JSONWeatherTask.doInBackground(RollMeOverActivity.java:1)
    at android.os.AsyncTask$2.call(AsyncTask.java:288)
    at java.util.concurrent.FutureTask.run(FutureTask.java:237)
    at android.os.AsyncTask$SerialExecutor$1.run(AsyncTask.java:231)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1112)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:587)
    at java.lang.Thread.run(Thread.java:841)

  19. Line 44 is

    JSONObject jObj = new JSONObject(data);

    The only comment preceding it was
    // We create out JSONObject from the data

    I had a longer first post, (above is second) which I provided more detail, I assume you read and deleted it? Thanks for the quick response.

  20. Remove the con.setDoOutput(true); statement in getImage(). Not sure exactly why, but it does to trick.

    PS: Without this it gives 405 status code, which means server refused to send data probably due to some headers it didn't expect tosee in request (just a guess). You can read info on error 405 here – http://www.checkupdown.com/status/E405.html

  21. In this line:
    JSONObject jObj = new JSONObject(data);

    What is “data”???? where do you get it from?

  22. save your previous result into a SQLite database, then in next session If you haven’t Internet connection you can load data from it, other, clear database and save new result into database

  23. Hi,
    I was developing weather application using openweathermap api, before 2months all are working fine, but now for certain city’s i couldn’t able to fetch the response eg for chennai(Using volley- Error code: BasicNetwork.performRequest: Unexpected response code 401 for http://api.openweathermap.org/data/2.5/weather?q=Chennai&appid=44db6a862fba0b067b1930da0d769e98) but it is working fine in browser and postman

    Plz suggest to find out where i am missing out

  24. Caused by: java.lang.NullPointerException: Attempt to invoke virtual method ‘int java.lang.String.length()’ on a null object reference
    at org.json.JSONTokener.nextCleanInternal(JSONTokener.java:116)
    at org.json.JSONTokener.nextValue(JSONTokener.java:94)
    at org.json.JSONObject.(JSONObject.java:156)
    at org.json.JSONObject.(JSONObject.java:173)
    at hdonlinetv.live.myapplication.JSONWeatherParser.getWeather(JSONWeatherParser.java:18)
    at hdonlinetv.live.myapplication.MainActivity$JSONWeatherTask.doInBackground(MainActivity.java:57)
    at hdonlinetv.live.myapplication.MainActivity$JSONWeatherTask.doInBackground(MainActivity.java

    This error is coming .. Kindly help me with this. Thnx

  25. Obtiene los datos del tiempo para automatizadores de radios emisoras, muy fácil de instalar y de configurar.

    Basado en una plataforma web, consume muy pocos recursos. Viene con una API por defecto, la cual puede ser reemplazada por otra, y solo hay que poner ciudad,país.

    Ejemplo: Madrid,es

    Rápidamente configurable desde la interface web, con soporte desde la pagina web del proyecto y podes dejarnos tus comentarios.

    Se basa en instalar un servidor local AppServ 2.5.10 que a través unos pocos archivos se obtienen los datos del tiempo obtenidos desde openweathermap org de forma totalmente gratuita.

    La versión Meteo V.1.0.2 de Radit ha quedado obsoleta y necesita una actualización.

    Es un software LIBRE. con código abierto.

    Derivado que las donaciones no son lo suficientes para continuar con un excelente proyecto de software libre.

  26. It would be great if a video tutorial was available or the full example was explained because right now I don’t even know where goes where

  27. hello sir
    i’m working on a weather based android app and have an query that “how to modify the api URL according to the request of user” i.e in general we set the name of the city statically in URL whose weather we want to see but how to set the name of the city dynamically according to the user requirement ?

    please help me!

    thanks in advance.

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