Java tutorial
/* * Copyright 2013 Google Inc. * * 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. */ package edu.mines.letschat; import com.google.android.gms.common.ConnectionResult; import com.google.android.gms.common.GooglePlayServicesUtil; import com.google.android.gms.gcm.GoogleCloudMessaging; import android.app.Activity; import android.app.ProgressDialog; import android.content.Context; import android.content.Intent; import android.content.SharedPreferences; import android.content.pm.PackageInfo; import android.content.pm.PackageManager.NameNotFoundException; import android.os.AsyncTask; import android.os.Bundle; import android.preference.PreferenceManager; import android.util.Log; import android.view.View; import android.widget.AdapterView; import android.widget.AdapterView.OnItemClickListener; import android.widget.ArrayAdapter; import android.widget.ListView; import android.widget.TextView; import java.io.BufferedReader; import java.io.IOException; import java.io.InputStream; import java.io.InputStreamReader; import java.util.ArrayList; import java.util.HashMap; import java.util.List; import java.util.Map.Entry; import java.util.concurrent.ExecutionException; import java.util.concurrent.atomic.AtomicInteger; import org.apache.http.HttpEntity; import org.apache.http.HttpResponse; import org.apache.http.NameValuePair; import org.apache.http.client.ClientProtocolException; import org.apache.http.client.HttpClient; import org.apache.http.client.entity.UrlEncodedFormEntity; import org.apache.http.client.methods.HttpPost; import org.apache.http.impl.client.DefaultHttpClient; import org.apache.http.message.BasicNameValuePair; import org.json.JSONArray; import org.json.JSONException; import org.json.JSONObject; /** * Main UI for the demo app. */ public class MainActivity extends Activity { public static final String EXTRA_MESSAGE = "message"; public static final String PROPERTY_REG_ID = "registration_id"; private static final String PROPERTY_APP_VERSION = "appVersion"; private static final int PLAY_SERVICES_RESOLUTION_REQUEST = 9000; public static final String EXTRA_USER_NAME = "edu.mines.letschat.EXTRA_USER_NAME"; public static final String EXTRA_DEVICE_ID = "edu.mines.letschat.EXTRA_DEVICE_ID"; public static final String EXTRA_SENDER_ID = "edu.mines.letschat.EXTRA_SENDER_ID"; public static final String EXTRA_NOTIFICATION_RETRIEVE = "edu.mines.letschat.EXTRA_NOTIFICATION_RETRIEVE"; private static SharedPreferences sharedPref; public String username, password; private ArrayList<String> users = new ArrayList<String>(); public HashMap<String, String> map; static final String TAG = "GCM Demo"; TextView mDisplay; GoogleCloudMessaging gcm; AtomicInteger msgId = new AtomicInteger(); Context context; String string; static String regid; @Override public void onNewIntent(Intent intent) { super.onNewIntent(intent); Log.v(TAG, "In on new intent"); Bundle extras = intent.getExtras(); if (extras != null) { string = extras.getString(EXTRA_NOTIFICATION_RETRIEVE); if (string != null) { // users.clear(); // new GetUsers(new OnTaskCompleted() { // @Override // public void onTaskCompleted() { Intent tent = new Intent(MainActivity.this, MessageActivity.class); tent.putExtra(MainActivity.EXTRA_DEVICE_ID, string); tent.putExtra(MainActivity.EXTRA_SENDER_ID, regid); for (Entry<String, String> entry : map.entrySet()) { if (string.equals(entry.getValue())) { String username = entry.getKey(); Log.v(TAG, username); tent.putExtra(MainActivity.EXTRA_USER_NAME, username); } } startActivity(tent); // } // }).execute(); } } } @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); sharedPref = PreferenceManager.getDefaultSharedPreferences(getApplicationContext()); if (!sharedPref.getBoolean("loggedIn", false)) { Intent intent = new Intent(this, LoginActivity.class); startActivity(intent); } context = getApplicationContext(); username = getIntent().getStringExtra(LoginActivity.EXTRA_LOGIN); password = getIntent().getStringExtra(LoginActivity.EXTRA_PASSWORD); // Check device for Play Services APK. If check succeeds, proceed with GCM registration. if (checkPlayServices()) { gcm = GoogleCloudMessaging.getInstance(this); regid = getRegistrationId(context); if (regid.isEmpty()) { registerInBackground(); } else { Log.v(TAG, regid); new GetUsers(new OnTaskCompleted() { @Override public void onTaskCompleted() { onNewIntent(getIntent()); } }).execute(); } } else { Log.i(TAG, "No valid Google Play Services APK found."); } } @Override protected void onResume() { super.onResume(); // Check device for Play Services APK. checkPlayServices(); if (!sharedPref.getBoolean("loggedIn", false)) { Intent intent = new Intent(this, LoginActivity.class); startActivity(intent); } } /** * Check the device to make sure it has the Google Play Services APK. If * it doesn't, display a dialog that allows users to download the APK from * the Google Play Store or enable it in the device's system settings. */ private boolean checkPlayServices() { int resultCode = GooglePlayServicesUtil.isGooglePlayServicesAvailable(this); if (resultCode != ConnectionResult.SUCCESS) { if (GooglePlayServicesUtil.isUserRecoverableError(resultCode)) { GooglePlayServicesUtil.getErrorDialog(resultCode, this, PLAY_SERVICES_RESOLUTION_REQUEST).show(); } else { Log.i(TAG, "This device is not supported."); finish(); } return false; } return true; } /** * Gets the current registration ID for application on GCM service, if there is one. * <p> * If result is empty, the app needs to register. * * @return registration ID, or empty string if there is no existing * registration ID. */ private String getRegistrationId(Context context) { final SharedPreferences prefs = getGcmPreferences(context); String registrationId = prefs.getString(PROPERTY_REG_ID, ""); if (registrationId.isEmpty()) { Log.i(TAG, "Registration not found."); return ""; } // Check if app was updated; if so, it must clear the registration ID // since the existing regID is not guaranteed to work with the new // app version. int registeredVersion = prefs.getInt(PROPERTY_APP_VERSION, Integer.MIN_VALUE); int currentVersion = getAppVersion(context); if (registeredVersion != currentVersion) { Log.i(TAG, "App version changed."); return ""; } return registrationId; } /** * @return Application's version code from the {@code PackageManager}. */ private static int getAppVersion(Context context) { try { PackageInfo packageInfo = context.getPackageManager().getPackageInfo(context.getPackageName(), 0); return packageInfo.versionCode; } catch (NameNotFoundException e) { // should never happen throw new RuntimeException("Could not get package name: " + e); } } /** * @return Application's {@code SharedPreferences}. */ private SharedPreferences getGcmPreferences(Context context) { // This sample app persists the registration ID in shared preferences, but // how you store the regID in your app is up to you. return context.getSharedPreferences(MainActivity.class.getSimpleName(), Context.MODE_PRIVATE); } /** * Registers the application with GCM servers asynchronously. * <p> * Stores the registration ID and the app versionCode in the application's * shared preferences. */ private void registerInBackground() { try { regid = new RegisterInBackgroundTask(gcm, MainActivity.this, regid, username, password, new OnTaskCompleted() { @Override public void onTaskCompleted() { new GetUsers(new OnTaskCompleted() { @Override public void onTaskCompleted() { onNewIntent(getIntent()); } }).execute(); } }).execute().get(); } catch (InterruptedException e) { e.printStackTrace(); } catch (ExecutionException e) { e.printStackTrace(); } } // // Send an upstream message. // public void onClick(final View view) { // // if (view == findViewById(R.id.send)) { // new AsyncTask<Void, Void, String>() { // @Override // protected String doInBackground(Void... params) { // String msg = ""; // try { // Bundle data = new Bundle(); // data.putString("my_message", "Hello World"); // data.putString("my_action", "com.google.android.gcm.demo.app.ECHO_NOW"); // String id = Integer.toString(msgId.incrementAndGet()); // gcm.send(SENDER_ID + "@gcm.googleapis.com", id, data); // msg = "Sent message"; // } catch (IOException ex) { // msg = "Error :" + ex.getMessage(); // } // return msg; // } // // @Override // protected void onPostExecute(String msg) { // mDisplay.append(msg + "\n"); // } // }.execute(null, null, null); // } else if (view == findViewById(R.id.clear)) { // mDisplay.setText(""); // } // } @Override protected void onDestroy() { super.onDestroy(); } class GetUsers extends AsyncTask<String, String, String> { private static final String FUNCTION = "getAllUsers"; private static final String API = "http://justacomputerscientist.com/mobile/api.php"; private OnTaskCompleted listener; ProgressDialog dialog; public GetUsers(OnTaskCompleted listener) { this.listener = listener; } @Override protected void onPreExecute() { dialog = new ProgressDialog(MainActivity.this); dialog.setCancelable(false); dialog.setMessage("Getting users please wait..."); dialog.show(); } @Override protected String doInBackground(String... arg0) { HttpClient httpClient = new DefaultHttpClient(); HttpPost httpPost = new HttpPost(API); HttpResponse response; String result = ""; JSONArray jsonarray; List<NameValuePair> params = new ArrayList<NameValuePair>(1); params.add(new BasicNameValuePair("func", FUNCTION)); params.add(new BasicNameValuePair("deviceKey", regid)); map = new HashMap<String, String>(); try { httpPost.setEntity(new UrlEncodedFormEntity(params)); response = httpClient.execute(httpPost); HttpEntity entity = response.getEntity(); if (entity != null) { InputStream instream = entity.getContent(); result = convert(instream); instream.close(); jsonarray = new JSONArray(result); // looping through All Names for (int i = 0; i < jsonarray.length(); i++) { JSONObject obj = jsonarray.getJSONObject(i); // Storing each json item in variable String key = obj.getString("key"); String username = obj.getString("username"); map.put(username, key); users.add(username); } } } catch (ClientProtocolException e) { e.printStackTrace(); } catch (IOException e) { e.printStackTrace(); } catch (JSONException e) { e.printStackTrace(); } return result; } @Override protected void onPostExecute(String file_url) { dialog.dismiss(); ListView lv = (ListView) findViewById(R.id.list); lv.setAdapter(new ArrayAdapter<String>(MainActivity.this, android.R.layout.simple_list_item_1, users)); lv.setOnItemClickListener(new OnItemClickListener() { @Override public void onItemClick(AdapterView<?> arg0, View arg1, int arg2, long arg3) { Intent intent = new Intent(MainActivity.this, MessageActivity.class); intent.putExtra(MainActivity.EXTRA_DEVICE_ID, map.get(users.get(arg2))); intent.putExtra(MainActivity.EXTRA_SENDER_ID, regid); intent.putExtra(MainActivity.EXTRA_USER_NAME, users.get(arg2)); startActivity(intent); } }); listener.onTaskCompleted(); } public String convert(InputStream is) { /* * To convert the InputStream to String we use the BufferedReader.readLine() * method. We iterate until the BufferedReader return null which means * there's no more data to read. Each line will appended to a StringBuilder * and returned as String. */ BufferedReader reader = new BufferedReader(new InputStreamReader(is)); StringBuilder sb = new StringBuilder(); String line = null; try { while ((line = reader.readLine()) != null) { sb.append(line + "\n"); } } catch (IOException e) { e.printStackTrace(); } finally { try { is.close(); } catch (IOException e) { e.printStackTrace(); } } return sb.toString(); } } }