Java tutorial
package survivingwithandroid.com.uvindex; /* * Copyright (C) 2016, francesco Azzola * *(http://www.survivingwithandroid.com) * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. * */ import android.Manifest; import android.content.pm.PackageManager; import android.graphics.Color; import android.location.Location; import android.os.Bundle; import android.os.Handler; import android.support.annotation.NonNull; import android.support.annotation.Nullable; import android.support.annotation.RequiresPermission; import android.support.design.widget.FloatingActionButton; import android.support.design.widget.Snackbar; import android.support.v4.app.ActivityCompat; import android.support.v7.app.AppCompatActivity; import android.support.v7.widget.Toolbar; import android.view.View; import android.view.Menu; import android.view.MenuItem; import android.widget.TextView; import com.google.android.gms.common.ConnectionResult; import com.google.android.gms.common.api.GoogleApiClient; import com.google.android.gms.location.LocationListener; import com.google.android.gms.location.LocationRequest; import com.google.android.gms.location.LocationServices; import org.json.JSONException; import org.json.JSONObject; import java.io.IOException; import okhttp3.Call; import okhttp3.Callback; import okhttp3.OkHttpClient; import okhttp3.Request; import okhttp3.Response; public class MainActivity extends AppCompatActivity implements GoogleApiClient.OnConnectionFailedListener, GoogleApiClient.ConnectionCallbacks, LocationListener { private GoogleApiClient googleClient; private OkHttpClient httpClient; private static final String APP_ID = "83cbfb2b392a6f8caec0e83ab641e8d9"; private static final String UV_URL = "http://api.openweathermap.org/v3/uvi/"; private TextView coordView; private TextView uvView; private TextView msgView; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar); setSupportActionBar(toolbar); coordView = (TextView) findViewById(R.id.textCoord); uvView = (TextView) findViewById(R.id.textUV); msgView = (TextView) findViewById(R.id.textMsg); initGoogleClient(); FloatingActionButton fab = (FloatingActionButton) findViewById(R.id.fab); fab.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View view) { getUVIndex(); } }); // Init Http Client httpClient = new OkHttpClient(); } @Override public boolean onCreateOptionsMenu(Menu menu) { // Inflate the menu; this adds items to the action bar if it is present. getMenuInflater().inflate(R.menu.menu_main, menu); return true; } @Override public boolean onOptionsItemSelected(MenuItem item) { // Handle action bar item clicks here. The action bar will // automatically handle clicks on the Home/Up button, so long // as you specify a parent activity in AndroidManifest.xml. int id = item.getItemId(); //noinspection SimplifiableIfStatement if (id == R.id.action_settings) { return true; } return super.onOptionsItemSelected(item); } private void initGoogleClient() { googleClient = new GoogleApiClient.Builder(this).addConnectionCallbacks(this) .addOnConnectionFailedListener(this).addApi(LocationServices.API).build(); } // Connection failure @Override public void onConnectionFailed(@NonNull ConnectionResult connectionResult) { showErrorMessage(); return; } // Connection established @Override public void onConnected(@Nullable Bundle bundle) { getUVIndex(); } @Override public void onConnectionSuspended(int i) { } @Override protected void onStop() { googleClient.disconnect(); super.onStop(); } @Override protected void onStart() { googleClient.connect(); super.onStart(); } private void getUVIndex() { System.out.println("Get UV Index"); if (!googleClient.isConnected()) { // Try to connect again googleClient.connect(); } if (!googleClient.isConnected()) { showErrorMessage(); return; } try { Location loc = getLocation(); LocationRequest req = new LocationRequest(); req.setInterval(5 * 1000); req.setPriority(LocationRequest.PRIORITY_BALANCED_POWER_ACCURACY); LocationServices.FusedLocationApi.requestLocationUpdates(googleClient, req, this); } catch (SecurityException t) { t.printStackTrace(); } } @RequiresPermission(Manifest.permission.ACCESS_COARSE_LOCATION) private Location getLocation() { try { Location loc = LocationServices.FusedLocationApi.getLastLocation(googleClient); return loc; } catch (SecurityException se) { } return null; } private void showErrorMessage() { Snackbar.make(findViewById(R.id.mainLyt), "Unable to connect to Google Play service", Snackbar.LENGTH_LONG); } private void handleConnection(Location loc) { double lat = loc.getLatitude(); double lon = loc.getLongitude(); // Make HTTP request according to Openweathermap API String url = UV_URL + ((int) lat) + "," + ((int) lon) + "/current.json?appid=" + APP_ID; System.out.println("URL [" + url + "]"); Request request = new Request.Builder().url(url).build(); httpClient.newCall(request).enqueue(new Callback() { @Override public void onFailure(Call call, IOException e) { // Handle failure in HTTP request } @Override public void onResponse(Call call, Response response) throws IOException { // Ok we have the response...parse it try { JSONObject obj = new JSONObject(response.body().string()); final double uvIndex = obj.optDouble("data"); System.out.println("UV Index [" + uvIndex + "]"); JSONObject jsonLoc = obj.getJSONObject("location"); final double cLon = jsonLoc.getDouble("longitude"); final double cLat = jsonLoc.getDouble("latitude"); Handler handler = new Handler(MainActivity.this.getMainLooper()); handler.post(new Runnable() { @Override public void run() { coordView.setText(cLat + "," + cLon); uvView.setText(String.valueOf(uvIndex)); if (uvIndex <= 2.9) { uvView.setTextColor(Color.GREEN); msgView.setText("Low"); } else if (uvIndex <= 5.9) { uvView.setTextColor(Color.YELLOW); msgView.setText("Moderate"); } else if (uvIndex <= 7.9) { uvView.setTextColor(Color.parseColor("#DF7401")); msgView.setText("High"); } else if (uvIndex <= 10.9) { uvView.setTextColor(Color.RED); msgView.setText("Very High"); } else if (uvIndex >= 11) { uvView.setTextColor(Color.parseColor("#8258FA")); msgView.setText("Extreme"); } } }); } catch (JSONException jex) { jex.printStackTrace(); } } }); } @Override public void onLocationChanged(Location location) { handleConnection(location); } }