Android get device locale

Question 1

There's a much simpler and cleaner way to do this than using reflection or parsing some system property.

As you noticed once you set the default Locale in your app you don't have access to the system default Locale any more. The default Locale you set in your app is valid only during the life cycle of your app. Whatever you set in your Locale.setDefault(Locale) is gone once the process is terminated . When the app is restarted you will again be able to read the system default Locale.

So all you need to do is retrieve the system default Locale when the app starts, remember it as long as the app runs and update it should the user decide to change the language in the Android settings. Because we need that piece of information only as long as the app runs, we can simply store it in a static variable, which is accessible from anywhere in your app.

And here's how we do it:

public class MyApplication extends Application {
    
    public static String sDefSystemLanguage;
    
    @Override
    public void onCreate() {
        super.onCreate();

        sDefSystemLanguage = Locale.getDefault().getLanguage();
    }

    @Override
    public void onConfigurationChanged(Configuration newConfig) {
        super.onConfigurationChanged(newConfig);

        sDefSystemLanguage = newConfig.locale.getLanguage();
    }

}

Using an Application (don't forget to define it in your manifest) we get the default locale when the app starts (onCreate()) and we update it when the user changes the language in the Android settings (onConfigurationChanged(Configuration)). That's all there is. Whenever you need to know what the system default language was before you used your setDefault call, sDefSystemLanguage will give you the answer.

There's one issue I spotted in your code. When you set the new Locale you do:

Configuration config = new Configuration();
config.locale = locale;
pContext.getResources().updateConfiguration(config, null);

When you do that, you overwrite all Configuration information that you might want to keep. E.g. Configuration.fontScale reflects the Accessibility settings Large Text. By settings the language and losing all other Configuration your app would not reflect the Large Text settings any more, meaning text is smaller than it should be (if the user has enabled the large text setting). The correct way to do it is:

Resources res = pContext.getResources();
Configuration config = res.getConfiguration();
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.JELLY_BEAN_MR1) {
    configuration.setLocale(locale);
}
else {
    configuration.locale = locale;
}
res.updateConfiguration(config, null);

So instead of creating a new Configuration object we just update the current one.

Question 2

Update: As pointed out in comments 'locale' field is deprecated and you need to use getLocales() instead.

defaultLocale = Resources.getSystem().getConfiguration().getLocales().get(0);

You can access global locale by -

defaultLocale = Resources.getSystem().getConfiguration().locale;

Take a look at http://developer.android.com/reference/android/content/res/Resources.html#getSystem() -

Returns a global shared Resources object that provides access to only system resources (no application resources)

Question 3

The best way to design the app is to use a default lang, English in your case, under values/ and you can add addition langs under values-XX/. In this way when a language is not supported Android fallback to your default, so English. Let the OS does the work for you :) However, yes if you change the locale you'll get your last settings, so you have to save that information somewhere.

Question 4

As you are changing the Application language programatically like

Locale locale = new Locale("en");
Locale.setDefault(locale);
Configuration config = new Configuration();
config.locale = locale;
pContext.getResources().updateConfiguration(config, null);

And

But after that, in other methods, when I check device's locale like this:

String deviceLocale=Locale.getDefault().getLanguage();
I get result as "English". But device's locale is Spanish.

So instead of that use this below code to get the device's Local

try {
    Process exec = Runtime.getRuntime().exec(new String[]{"getprop", "persist.sys.language"});
    String locale = new BufferedReader(new InputStreamReader(exec.getInputStream())).readLine();
    exec.destroy();
    Log.e("", "Device locale: "+locale);
} catch (IOException e) {
    e.printStackTrace();
}

OUTPUT: Spanish Check this

Hope this exactly you are looking for.

Question 5

you should use String deviceLocale= Locale.getDefault().getDisplayLanguage(); to display the language instead of

String deviceLocale=Locale.getDefault().getLanguage();

check out this answer it may help you if above does not. Clickable

Question 6

Although, the answer by @user2944616 is politically correct, that does not give an answer to the actual question posed.

So, if I really had to know the user set system locale, I'd use reflection (do not know any better option ATM):

private String getSystemPropertyValue(String name) {
    try {
        Class<?> systemProperties = Class.forName("android.os.SystemProperties");
        try {
            Method get = systemProperties.getMethod("get", String.class, String.class);
            if (get == null) {
                return "Failure!?";
            }
            try {
                return (String)get.invoke(systemProperties, name, "");
            } catch (IllegalAccessException e) {
                return "IllegalAccessException";
            } catch (IllegalArgumentException e) {
                return "IllegalArgumentException";
            } catch (InvocationTargetException e) {
                return "InvocationTargetException";
            }
        } catch (NoSuchMethodException e) {
            return "SystemProperties.get(String key, String def) method is not found";
        }
    } catch (ClassNotFoundException e) {
        return "SystemProperties class is not found";
    }
}

With that given and device locale set to Spanish (United States) / Español (Estados Unidos) following string

<string name="system_locale">System locale: <xliff:g id="profile_name">%1$s</xliff:g>&#95;<xliff:g id="device_name">%2$s</xliff:g></string>

and this code

private static final String SYS_COUNTRY = "persist.sys.country";
private static final String SYS_LANG = "persist.sys.language";

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

    TextView tv = (TextView)findViewById(R.id.locale);
    tv.setText(getString(R.string.system_locale, getSystemPropertyValue(SYS_LANG),
            getSystemPropertyValue(SYS_COUNTRY)));
}

yields following screen:

System locale screenshot

If desired, one could also easily construct Locale instance using the above:

Locale locale = new Locale(getSystemPropertyValue(SYS_LANG),
        getSystemPropertyValue(SYS_COUNTRY));
Log.d(TAG, "Language: " + locale.getLanguage());
Log.d(TAG, "Country: " + locale.getCountry());

Log output:

D/GetSystemLocale(5697): Language: es
D/GetSystemLocale(5697): Country: US

Hope this helps.

Question 7

To get the device locale use this

Locale current = context.getResources().getConfiguration().locale;

and current.toString() will return you "en" "ar" etc