Develop Reference

Not getting response from youtube data api

I am new to android, I am trying to implement YouTube's search by keyword in my android app.But I am not able to get response from API (I think).I think there is some problem in search.execute().I looked some other answers too but not able to find any solution.
Here's the class (I modified it a little bit):
class Search {
private static final long NUMBER_OF_VIDEOS_RETURNED = 2;
/**
* Define a global instance of a Youtube object, which will be used
* to make YouTube Data API requests.
*/
private YouTube youtube;
/**
* Initialize a YouTube object to search for videos on YouTube. Then
* display the name and thumbnail image of each video in the result set.
*
*
*/
private void Hakuna() {
// Read the developer key from the properties file.
try {
// This object is used to make YouTube Data API requests. The last
// argument is required, but since we don't need anything
// initialized when the HttpRequest is initialized, we override
// the interface and provide a no-op function.
youtube = new YouTube.Builder(new NetHttpTransport(), new JacksonFactory(), new HttpRequestInitializer() {
public void initialize(HttpRequest request) throws IOException {
}
}).setApplicationName("youtube-cmdline-search-sample").build();
// Prompt the user to enter a query term.
String queryTerm = getInputQuery();
// Define the API request for retrieving search results.
YouTube.Search.List search = youtube.search().list("id,snippet");
// Set your developer key from the {{ Google Cloud Console }} for
// non-authenticated requests. See:
// {{ https://cloud.google.com/console }}
String apiKey = "HERE_I_PUT_MY_APIKEY";
search.setKey(apiKey);
search.setQ(queryTerm);
// Restrict the search results to only include videos. See:
// https://developers.google.com/youtube/v3/docs/search/list#type
search.setType("video");
// To increase efficiency, only retrieve the fields that the
// application uses.
search.setFields("items(id/kind,id/videoId,snippet/title,snippet/thumbnails/default/url)");
search.setMaxResults(NUMBER_OF_VIDEOS_RETURNED);
// Call the API and print results.
SearchListResponse searchResponse = search.execute();
mResult.setText("hello");
List<SearchResult> searchResultList = searchResponse.getItems();
if (searchResultList != null) {
prettyPrint(searchResultList.iterator(), queryTerm);
}
} catch (GoogleJsonResponseException e) {
System.err.println("There was a service error: " + e.getDetails().getCode() + " : "
+ e.getDetails().getMessage());
} catch (IOException e) {
System.err.println("There was an IO error: " + e.getCause() + " : " + e.getMessage());
} catch (Throwable t) {
t.printStackTrace();
}
}
/*
* Prompt the user to enter a query term and return the user-specified term.
*/
private String getInputQuery() throws IOException {
String inputQuery = "";
inputQuery = mSearchtext.getText().toString();
if (inputQuery.length() < 1) {
// Use the string "YouTube Developers Live" as a default.
inputQuery = "YouTube Developers Live";
}
return inputQuery;
}
/*
* Prints out all results in the Iterator. For each result, print the
* title, video ID, and thumbnail.
*
* #param iteratorSearchResults Iterator of SearchResults to print
*
* #param query Search query (String)
*/
private void prettyPrint(Iterator<SearchResult> iteratorSearchResults, String query) {
mResult.setText("hello");
System.out.println("\n=============================================================");
System.out.println(
" First " + NUMBER_OF_VIDEOS_RETURNED + " videos for search on \"" + query + "\".");
System.out.println("=============================================================\n");
if (!iteratorSearchResults.hasNext()) {
System.out.println(" There aren't any results for your query.");
}
while (iteratorSearchResults.hasNext()) {
SearchResult singleVideo = iteratorSearchResults.next();
ResourceId rId = singleVideo.getId();
// Confirm that the result represents a video. Otherwise, the
// item will not contain a video ID.
if (rId.getKind().equals("youtube#video")) {
Thumbnail thumbnail = singleVideo.getSnippet().getThumbnails().getDefault();
System.out.println(" Video Id" + rId.getVideoId());
System.out.println(" Title: " + singleVideo.getSnippet().getTitle());
System.out.println(" Thumbnail: " + thumbnail.getUrl());
System.out.println("\n-------------------------------------------------------------\n");
}
}
}
}
Here are the dependencies that I added:
implementation fileTree(dir: 'libs', include: ['*.jar'])
implementation 'com.android.support:appcompat-v7:27.1.1'
implementation 'com.android.support.constraint:constraint-layout:1.1.2'
implementation 'com.google.apis:google-api-services-youtube:v3-rev181-1.22.0'
There may be some redundant lines of code, please ignore them.

Google Drive REST API Notifications not working for changes in app folder

According to the documentation it should be possible to register a notification channel for changes to the app folder of my app, using setSpaces("appDataFolder").
However, I only get an initial sync notification when setting up the channel, but no change notifications when I change something in the app folder.
If I use setSpaces("drive") or omit the setSpaces() altogether and change something in regular drive space, I receive change notifications alright.
I didn't find anything about watching for changes in the app folder, so I hope someone here can help me.
This is how I set up the channel, where mDrive is a fully initialized and authorized instance of com.google.api.services.drive.Drive
channelId = UUID.randomUUID().toString();
channelExpiration = System.currentTimeMillis() + CHANNEL_LIVETIME_MILLIS;
Channel channel = new Channel();
channel.setType("web_hook");
channel.setId(channelId);
channel.setAddress(DRIVE_API_CALLBACK_RECEIVER_URL);
channel.setToken("...");
channel.setExpiration(channelExpiration);
Channel result = mDrive.changes().watch(channel).setSpaces("appDataFolder").execute();

Is there a scope where you set this up? Make sure you have a broad enough scope to include 'appDataFolder'. By this I mean you should be able to get some results from this (from here):
/**
* Print metadata for the Application Data folder.
*
* #param service Drive API service instance.
*/
private static void printApplicationDataFolderMetadata(Drive service) {
try {
File file = service.files().get("appfolder").execute();
System.out.println("Id: " + file.getId());
System.out.println("Title: " + file.getTitle());
} catch (IOException e) {
System.out.println("An error occured: " + e);
}
}
I think the above might be your problem. Whereever you are setting scope make sure to include the drive.appfolder or more formally
https://www.googleapis.com/auth/drive.appfolder
Furthermore, are you checking if result is null? You really should put the Channel result =... line in a try {} catch(IOExeption e) {} and print the error if there is one like in this example (from here).
/**
* Watch for all changes to a user's Drive.
*
* #param service Drive API service instance.
* #param channelId Unique string that identifies this channel.
* #param channelType Type of delivery mechanism used for this channel.
* #param channelAddress Address where notifications are delivered.
* #return The created channel if successful, {#code null} otherwise.
*/
private static Channel watchChange(Drive service, String channelId,
String channelType, String channelAddress) {
Channel channel = new Channel();
channel.setId(channelId);
channel.setType(channelType);
channel.setAddress(channelAddress);
try {
return service.changes().watch(channel).execute();
} catch (IOException e) {
e.printStackTrace();
// ADD A LOG OR PRINT STATEMENT HERE
Log.e("DRIVEAPI", "Error: " + e.toString())
}
return null;
}
Which for you code should look like this:
channelId = UUID.randomUUID().toString();
channelExpiration = System.currentTimeMillis() + CHANNEL_LIVETIME_MILLIS;
Channel channel = new Channel();
channel.setType("web_hook");
channel.setId(channelId);
channel.setAddress(DRIVE_API_CALLBACK_RECEIVER_URL);
channel.setToken("...");
channel.setExpiration(channelExpiration);
try {
Channel result = mDrive.changes().watch(channel).setSpaces("appDataFolder").execute();
if(result != null) {
// do whatever you want with result Channel
} else {
Log.e("DRIVEAPI", "Error: result is null for some reason!");
}
} catch (IOException e) {
e.printStackTrace()
Log.e("DRIVEAPI", "Error: " + e.toString());
}

How to search youtube video in Android by specific keyword

I'm trying to search youtube video based on given keyword. So that I can list all found video to display in a list with video thumbnail. I don't find a way to do so. After searching I found this https://developers.google.com/youtube/v3/docs/videos/list#examples.
Can I use save for my android application? Or how do I search in Android application?

You can use the Youtube API code samples in your app on the following conditions:
1. Your app is a free app.
2. If your app is monetized (paid, ads, and/or in app purchases) then your app has to contain more content and features than just a feature searching Youtube.
Full details here:
https://developers.google.com/youtube/creating_monetizable_applications
That being said, you can fully use code samples from Youtube API. I have done so myself to create an Android app to help people find all my favorite cat videos (shameless promotion): Cat Roulette
Anyhow, here is a specific Java code example for searching Youtube videos:
https://developers.google.com/youtube/v3/code_samples/java#search_by_keyword
/*
* Copyright (c) 2012 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 com.google.api.services.samples.youtube.cmdline.data;
import com.google.api.client.googleapis.json.GoogleJsonResponseException;
import com.google.api.client.http.HttpRequest;
import com.google.api.client.http.HttpRequestInitializer;
import com.google.api.client.http.HttpTransport;
import com.google.api.client.http.javanet.NetHttpTransport;
import com.google.api.client.json.JsonFactory;
import com.google.api.client.json.jackson2.JacksonFactory;
import com.google.api.services.samples.youtube.cmdline.Auth;
import com.google.api.services.youtube.YouTube;
import com.google.api.services.youtube.model.ResourceId;
import com.google.api.services.youtube.model.SearchListResponse;
import com.google.api.services.youtube.model.SearchResult;
import com.google.api.services.youtube.model.Thumbnail;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.util.Iterator;
import java.util.List;
import java.util.Properties;
/**
* Print a list of videos matching a search term.
*
* #author Jeremy Walker
*/
public class Search {
/**
* Define a global variable that identifies the name of a file that
* contains the developer's API key.
*/
private static final String PROPERTIES_FILENAME = "youtube.properties";
private static final long NUMBER_OF_VIDEOS_RETURNED = 25;
/**
* Define a global instance of a Youtube object, which will be used
* to make YouTube Data API requests.
*/
private static YouTube youtube;
/**
* Initialize a YouTube object to search for videos on YouTube. Then
* display the name and thumbnail image of each video in the result set.
*
* #param args command line args.
*/
public static void main(String[] args) {
// Read the developer key from the properties file.
Properties properties = new Properties();
try {
InputStream in = Search.class.getResourceAsStream("/" + PROPERTIES_FILENAME);
properties.load(in);
} catch (IOException e) {
System.err.println("There was an error reading " + PROPERTIES_FILENAME + ": " + e.getCause()
+ " : " + e.getMessage());
System.exit(1);
}
try {
// This object is used to make YouTube Data API requests. The last
// argument is required, but since we don't need anything
// initialized when the HttpRequest is initialized, we override
// the interface and provide a no-op function.
youtube = new YouTube.Builder(Auth.HTTP_TRANSPORT, Auth.JSON_FACTORY, new HttpRequestInitializer() {
public void initialize(HttpRequest request) throws IOException {
}
}).setApplicationName("youtube-cmdline-search-sample").build();
// Prompt the user to enter a query term.
String queryTerm = getInputQuery();
// Define the API request for retrieving search results.
YouTube.Search.List search = youtube.search().list("id,snippet");
// Set your developer key from the Google Developers Console for
// non-authenticated requests. See:
// https://console.developers.google.com/
String apiKey = properties.getProperty("youtube.apikey");
search.setKey(apiKey);
search.setQ(queryTerm);
// Restrict the search results to only include videos. See:
// https://developers.google.com/youtube/v3/docs/search/list#type
search.setType("video");
// To increase efficiency, only retrieve the fields that the
// application uses.
search.setFields("items(id/kind,id/videoId,snippet/title,snippet/thumbnails/default/url)");
search.setMaxResults(NUMBER_OF_VIDEOS_RETURNED);
// Call the API and print results.
SearchListResponse searchResponse = search.execute();
List<SearchResult> searchResultList = searchResponse.getItems();
if (searchResultList != null) {
prettyPrint(searchResultList.iterator(), queryTerm);
}
} catch (GoogleJsonResponseException e) {
System.err.println("There was a service error: " + e.getDetails().getCode() + " : "
+ e.getDetails().getMessage());
} catch (IOException e) {
System.err.println("There was an IO error: " + e.getCause() + " : " + e.getMessage());
} catch (Throwable t) {
t.printStackTrace();
}
}
/*
* Prompt the user to enter a query term and return the user-specified term.
*/
private static String getInputQuery() throws IOException {
String inputQuery = "";
System.out.print("Please enter a search term: ");
BufferedReader bReader = new BufferedReader(new InputStreamReader(System.in));
inputQuery = bReader.readLine();
if (inputQuery.length() < 1) {
// Use the string "YouTube Developers Live" as a default.
inputQuery = "YouTube Developers Live";
}
return inputQuery;
}
/*
* Prints out all results in the Iterator. For each result, print the
* title, video ID, and thumbnail.
*
* #param iteratorSearchResults Iterator of SearchResults to print
*
* #param query Search query (String)
*/
private static void prettyPrint(Iterator<SearchResult> iteratorSearchResults, String query) {
System.out.println("\n=============================================================");
System.out.println(
" First " + NUMBER_OF_VIDEOS_RETURNED + " videos for search on \"" + query + "\".");
System.out.println("=============================================================\n");
if (!iteratorSearchResults.hasNext()) {
System.out.println(" There aren't any results for your query.");
}
while (iteratorSearchResults.hasNext()) {
SearchResult singleVideo = iteratorSearchResults.next();
ResourceId rId = singleVideo.getId();
// Confirm that the result represents a video. Otherwise, the
// item will not contain a video ID.
if (rId.getKind().equals("youtube#video")) {
Thumbnail thumbnail = singleVideo.getSnippet().getThumbnails().getDefault();
System.out.println(" Video Id" + rId.getVideoId());
System.out.println(" Title: " + singleVideo.getSnippet().getTitle());
System.out.println(" Thumbnail: " + thumbnail.getUrl());
System.out.println("\n-------------------------------------------------------------\n");
}
}
}
}
FYI you have to also obtain a Youtube API key as explained here:
https://developers.google.com/youtube/registering_an_application?hl=en

How to implement a changelog in android?

for my app i want to implement a changelog, but dont know how (which concept).
I want, that the changelog pops up once a time after new version of my app installed.
Sounds easy, but i have no clue. :/
Dialog to show my Changelog exists already, i just wanna know how to show it one after an update.
Thanks for your hints.
Prexx

one option is to use Android Change Log.
With Android Change Log you can easily create, show and maintain an
Android change log dialog.
Features
display only what's new or show the whole change log
display on first start of newly installed app or on new app version
write the change log in a simplified language but also use HTML and
CSS if needed

You can store a value in SharedPreferences which version you showed the changelog last time.
E.g.: 'lastChangelogVersion' : '1.1.0'
When your MainActivity starts it compares this value with the current version of your software and if it differs the changelog popup appears (and sets the new value).
This value will not be overridden when a new version of your application is being installed.
UPDATE:
Also, you might encounter that the user cleared your application's data. In this case you can't decide whether the changelog was displayed before or not so you can show it again. Android Market works the same way: if you clear it's app data you will be facing with the Licence Agreement again when launching Market.

I found the following options for adding a changelog to your Android app. Using any of these libraries would definitely save time over implementing this yourself. They all follow the general approach that #papaiatis mentions in his answer.
changeloglib
ckChangeLog
paperboy
changelog
android-change-log
Appnouncements (Disclaimer: I'm the author of this one)

I found Michael Flisar's change log (https://github.com/MFlisar/changelog) extremely easy to use.
After an app update I show a "What's New" dialog by:
ChangelogBuilder builder = new ChangelogBuilder()
.withTitle("What\'s New")
.withUseBulletList(true)
.withManagedShowOnStart(true)
.buildAndShowDialog(activity, false);
And I can show an activity with the entire change log via:
ChangelogBuilder builder = new ChangelogBuilder()
.withTitle("Change Log")
.withUseBulletList(true)
.buildAndStartActivity(context, true);
Easy peasy.

/**
* Copyright (C) 2011-2013, Karsten Priegnitz
*
* Permission to use, copy, modify, and distribute this piece of software
* for any purpose with or without fee is hereby granted, provided that
* the above copyright notice and this permission notice appear in the
* source code of all copies.
*
* It would be appreciated if you mention the author in your change log,
* contributors list or the like.
*
* #author: Karsten Priegnitz
* #see: http://code.google.com/p/android-change-log/
*/
package sheetrock.panda.changelog;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import android.app.AlertDialog;
import android.content.Context;
import android.content.DialogInterface;
import android.content.SharedPreferences;
import android.content.pm.PackageManager.NameNotFoundException;
import android.graphics.Color;
import android.preference.PreferenceManager;
import android.util.Log;
import android.view.ContextThemeWrapper;
import android.webkit.WebView;
public class ChangeLog {
private final Context context;
private String lastVersion, thisVersion;
// this is the key for storing the version name in SharedPreferences
private static final String VERSION_KEY = "PREFS_VERSION_KEY";
private static final String NO_VERSION = "";
/**
* Constructor
*
* Retrieves the version names and stores the new version name in SharedPreferences
*
* #param context
*/
public ChangeLog(Context context) {
this(context, PreferenceManager.getDefaultSharedPreferences(context));
}
/**
* Constructor
*
* Retrieves the version names and stores the new version name in SharedPreferences
*
* #param context
* #param sp
* the shared preferences to store the last version name into
*/
public ChangeLog(Context context, SharedPreferences sp) {
this.context = context;
// get version numbers
this.lastVersion = sp.getString(VERSION_KEY, NO_VERSION);
Log.d(TAG, "lastVersion: " + lastVersion);
try {
this.thisVersion = context.getPackageManager().getPackageInfo(context.getPackageName(),
0).versionName;
} catch (NameNotFoundException e) {
this.thisVersion = NO_VERSION;
Log.e(TAG, "could not get version name from manifest!");
e.printStackTrace();
}
Log.d(TAG, "appVersion: " + this.thisVersion);
}
/**
* #return The version name of the last installation of this app (as described in the former
* manifest). This will be the same as returned by <code>getThisVersion()</code> the
* second time this version of the app is launched (more precisely: the second time
* ChangeLog is instantiated).
* #see AndroidManifest.xml#android:versionName
*/
public String getLastVersion() {
return this.lastVersion;
}
/**
* #return The version name of this app as described in the manifest.
* #see AndroidManifest.xml#android:versionName
*/
public String getThisVersion() {
return this.thisVersion;
}
/**
* #return <code>true</code> if this version of your app is started the first time
*/
public boolean firstRun() {
return !this.lastVersion.equals(this.thisVersion);
}
/**
* #return <code>true</code> if your app including ChangeLog is started the first time ever.
* Also <code>true</code> if your app was deinstalled and installed again.
*/
public boolean firstRunEver() {
return NO_VERSION.equals(this.lastVersion);
}
/**
* #return An AlertDialog displaying the changes since the previous installed version of your
* app (what's new). But when this is the first run of your app including ChangeLog then
* the full log dialog is show.
*/
public AlertDialog getLogDialog() {
return this.getDialog(this.firstRunEver());
}
/**
* #return an AlertDialog with a full change log displayed
*/
public AlertDialog getFullLogDialog() {
return this.getDialog(true);
}
protected AlertDialog getDialog(boolean full) {
WebView wv = new WebView(this.context);
wv.setBackgroundColor(Color.parseColor(context.getResources().getString(
R.string.background_color)));
wv.loadDataWithBaseURL(null, this.getLog(full), "text/html", "UTF-8", null);
AlertDialog.Builder builder = new AlertDialog.Builder(new ContextThemeWrapper(this.context,
android.R.style.Theme_Dialog));
builder.setTitle(
context.getResources().getString(
full ? R.string.changelog_full_title : R.string.changelog_title))
.setView(wv)
.setCancelable(false)
// OK button
.setPositiveButton(context.getResources().getString(R.string.changelog_ok_button),
new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int which) {
updateVersionInPreferences();
}
});
if (!full) {
// "more ..." button
builder.setNegativeButton(R.string.changelog_show_full,
new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int id) {
getFullLogDialog().show();
}
});
}
return builder.create();
}
protected void updateVersionInPreferences() {
// save new version number to preferences
SharedPreferences sp = PreferenceManager.getDefaultSharedPreferences(context);
SharedPreferences.Editor editor = sp.edit();
editor.putString(VERSION_KEY, thisVersion);
// // on SDK-Versions > 9 you should use this:
// if(Build.VERSION.SDK_INT < Build.VERSION_CODES.GINGERBREAD) {
// editor.commit();
// } else {
// editor.apply();
// }
editor.commit();
}
/**
* #return HTML displaying the changes since the previous installed version of your app (what's
* new)
*/
public String getLog() {
return this.getLog(false);
}
/**
* #return HTML which displays full change log
*/
public String getFullLog() {
return this.getLog(true);
}
/** modes for HTML-Lists (bullet, numbered) */
private enum Listmode {
NONE, ORDERED, UNORDERED,
};
private Listmode listMode = Listmode.NONE;
private StringBuffer sb = null;
private static final String EOCL = "END_OF_CHANGE_LOG";
protected String getLog(boolean full) {
// read changelog.txt file
sb = new StringBuffer();
try {
InputStream ins = context.getResources().openRawResource(R.raw.changelog);
BufferedReader br = new BufferedReader(new InputStreamReader(ins));
String line = null;
boolean advanceToEOVS = false; // if true: ignore further version
// sections
while ((line = br.readLine()) != null) {
line = line.trim();
char marker = line.length() > 0 ? line.charAt(0) : 0;
if (marker == '$') {
// begin of a version section
this.closeList();
String version = line.substring(1).trim();
// stop output?
if (!full) {
if (this.lastVersion.equals(version)) {
advanceToEOVS = true;
} else if (version.equals(EOCL)) {
advanceToEOVS = false;
}
}
} else if (!advanceToEOVS) {
switch (marker) {
case '%':
// line contains version title
this.closeList();
sb.append("<div class='title'>" + line.substring(1).trim() + "</div>\n");
break;
case '_':
// line contains version title
this.closeList();
sb.append("<div class='subtitle'>" + line.substring(1).trim() + "</div>\n");
break;
case '!':
// line contains free text
this.closeList();
sb.append("<div class='freetext'>" + line.substring(1).trim() + "</div>\n");
break;
case '#':
// line contains numbered list item
this.openList(Listmode.ORDERED);
sb.append("<li>" + line.substring(1).trim() + "</li>\n");
break;
case '*':
// line contains bullet list item
this.openList(Listmode.UNORDERED);
sb.append("<li>" + line.substring(1).trim() + "</li>\n");
break;
default:
// no special character: just use line as is
this.closeList();
sb.append(line + "\n");
}
}
}
this.closeList();
br.close();
} catch (IOException e) {
e.printStackTrace();
}
return sb.toString();
}
protected void openList(Listmode listMode) {
if (this.listMode != listMode) {
closeList();
if (listMode == Listmode.ORDERED) {
sb.append("<div class='list'><ol>\n");
} else if (listMode == Listmode.UNORDERED) {
sb.append("<div class='list'><ul>\n");
}
this.listMode = listMode;
}
}
protected void closeList() {
if (this.listMode == Listmode.ORDERED) {
sb.append("</ol></div>\n");
} else if (this.listMode == Listmode.UNORDERED) {
sb.append("</ul></div>\n");
}
this.listMode = Listmode.NONE;
}
private static final String TAG = "ChangeLog";
/**
* manually set the last version name - for testing purposes only
*
* #param lastVersion
*/
public void dontuseSetLastVersion(String lastVersion) {
this.lastVersion = lastVersion;
}
}

Android configuration file

What is the best way and how do I set up a configuration file for a application?
I want the application to be able to look into a text file on the SD card and pick out certain information that it requires.

If your application is going to be released to the public, and if you have sensitive data in your config, such as API keys or passwords, I would suggest to use secure-preferences instead of SharedPreferences since, ultimately, SharedPreferences are stored in an XML in clear text, and on a rooted phone, it is very easy for an application to access another's shared preferences.
By default it's not bullet proof security (in fact it's more like
obfuscation of the preferences) but it's a quick win for incrementally
making your android app more secure. For instance it'll stop users on
rooted devices easily modifying your app's shared prefs. (link)
I would suggest a few other methods:
*Method 1: Use a .properties file with Properties
Pros:
Easy to edit from whatever IDE you are using
More secure: since it is compiled with your app
Can easily be overridden if you use Build variants/Flavors
You can also write in the config
Cons:
You need a context
You can also write in the config (yes, it can also be a con)
(anything else?)
First, create a config file: res/raw/config.properties and add some values:
api_url=http://url.to.api/v1/
api_key=123456
You can then easily access the values with something like this:
package some.package.name.app;
import android.content.Context;
import android.content.res.Resources;
import android.util.Log;
import java.io.IOException;
import java.io.InputStream;
import java.util.Properties;
public final class Helper {
private static final String TAG = "Helper";
public static String getConfigValue(Context context, String name) {
Resources resources = context.getResources();
try {
InputStream rawResource = resources.openRawResource(R.raw.config);
Properties properties = new Properties();
properties.load(rawResource);
return properties.getProperty(name);
} catch (Resources.NotFoundException e) {
Log.e(TAG, "Unable to find the config file: " + e.getMessage());
} catch (IOException e) {
Log.e(TAG, "Failed to open config file.");
}
return null;
}
}
Usage:
String apiUrl = Helper.getConfigValue(this, "api_url");
String apiKey = Helper.getConfigValue(this, "api_key");
Of course, this could be optimized to read the config file once and get all values.
Method 2: Use AndroidManifest.xml meta-data element:
Personally, I've never used this method because it doesn't seem very flexible.
In your AndroidManifest.xml, add something like:
...
<application ...>
...
<meta-data android:name="api_url" android:value="http://url.to.api/v1/"/>
<meta-data android:name="api_key" android:value="123456"/>
</application>
Now a function to retrieve the values:
public static String getMetaData(Context context, String name) {
try {
ApplicationInfo ai = context.getPackageManager().getApplicationInfo(context.getPackageName(), PackageManager.GET_META_DATA);
Bundle bundle = ai.metaData;
return bundle.getString(name);
} catch (PackageManager.NameNotFoundException e) {
Log.e(TAG, "Unable to load meta-data: " + e.getMessage());
}
return null;
}
Usage:
String apiUrl = Helper.getMetaData(this, "api_url");
String apiKey = Helper.getMetaData(this, "api_key");
Method 3: Use buildConfigField in your Flavor:
I didn't find this in the official Android documentation/training, but this blog article is very useful.
Basically setting up a project Flavor (for example prod) and then in your app's build.gradle have something like:
productFlavors {
prod {
buildConfigField 'String', 'API_URL', '"http://url.to.api/v1/"'
buildConfigField 'String', 'API_KEY', '"123456"'
}
}
Usage:
String apiUrl = BuildConfig.API_URL;
String apiKey = BuildConfig.API_KEY;

You can achieve this using shared preferences
There is a very detailed guide on how to use Shared Preferences on the Google Android page
https://developer.android.com/guide/topics/data/data-storage.html#pref

If you want to store the preferences of your application, Android provides SharedPreferences for this.
Here is the link to official training resource.

I met such requirement recently, noting down here, how I did it.
the application to be able to look into a text file on the sd card and
pick out certain information that it requires
Requirement:
Configuration value(score_threshold) has to be available at the sdcard. So somebody can change the values after releasing the apk.
The config file must be available at the "/sdcard/config.txt" of the android hardware.
The config.txt file contents are,
score_threshold=60
Create a utility class Config.java, for reading and writing text file.
import android.util.Log;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.util.Properties;
public final class Config {
private static final String TAG = Config.class.getSimpleName();
private static final String FILE_PATH = Environment.getExternalStorageDirectory().getAbsolutePath() + "/config.txt";
private static Config sInstance = null;
/**
* Gets instance.
*
* #return the instance
*/
public static Config getInstance() {
if (sInstance == null) {
synchronized (Config.class) {
if (sInstance == null) {
sInstance = new Config();
}
}
}
return sInstance;
}
/**
* Write configurations values boolean.
*
* #return the boolean
*/
public boolean writeConfigurationsValues() {
try (OutputStream output = new FileOutputStream(FILE_PATH)) {
Properties prop = new Properties();
// set the properties value
prop.setProperty("score_threshold", "60");
// save properties
prop.store(output, null);
Log.i(TAG, "Configuration stored properties: " + prop);
return true;
} catch (IOException io) {
io.printStackTrace();
return false;
}
}
/**
* Get configuration value string.
*
* #param key the key
* #return the string
*/
public String getConfigurationValue(String key){
String value = "";
try (InputStream input = new FileInputStream(FILE_PATH)) {
Properties prop = new Properties();
// load a properties file
prop.load(input);
value = prop.getProperty(key);
Log.i(TAG, "Configuration stored properties value: " + value);
} catch (IOException ex) {
ex.printStackTrace();
}
return value;
}
}
Create another utility class to write the configuration file for the first time execution of the application,
Note: SD card read/write permission has to be set for the application.
public class ApplicationUtils {
/**
* Sets the boolean preference value
*
* #param context the current context
* #param key the preference key
* #param value the value to be set
*/
public static void setBooleanPreferenceValue(Context context, String key, boolean value) {
SharedPreferences sp = PreferenceManager.getDefaultSharedPreferences(context);
sp.edit().putBoolean(key, value).commit();
}
/**
* Get the boolean preference value from the SharedPreference
*
* #param context the current context
* #param key the preference key
* #return the the preference value
*/
public static boolean getBooleanPreferenceValue(Context context, String key) {
SharedPreferences sp = PreferenceManager.getDefaultSharedPreferences(context);
return sp.getBoolean(key, false);
}
}
At your Main Activity, onCreate()
if(!ApplicationUtils.getBooleanPreferenceValue(this,"isFirstTimeExecution")){
Log.d(TAG, "First time Execution");
ApplicationUtils.setBooleanPreferenceValue(this,"isFirstTimeExecution",true);
Config.getInstance().writeConfigurationsValues();
}
// get the configuration value from the sdcard.
String thresholdScore = Config.getInstance().getConfigurationValue("score_threshold");
Log.d(TAG, "thresholdScore from config file is : "+thresholdScore );