Android

currentLangDevice.java

Locale.getDefault().getLanguage()       ---> en      
Locale.getDefault().getISO3Language()   ---> eng 
Locale.getDefault().getCountry()        ---> US 
Locale.getDefault().getISO3Country()    ---> USA 
Locale.getDefault().getDisplayCountry() ---> United States 
Locale.getDefault().getDisplayName()    ---> English (United States) 
Locale.getDefault().toString()          ---> en_US
Locale.getDefault().getDisplayLanguage()---> English
Locale.getDefault().toLanguageTag()     ---> en-US

dateFormat.java

import android.text.format.DateFormat;
import java.util.Calendar;

// Parsing date
String dateFormated = "";
@SuppressLint("SimpleDateFormat") SimpleDateFormat formatterFrom = new SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ss.SSS");
@SuppressLint("SimpleDateFormat") SimpleDateFormat formatterTo = new SimpleDateFormat("HH:mm 'WIB'");
//formatterFrom.setTimeZone(TimeZone.getTimeZone("Asia/Jakarta"));
try {
      Date date = formatterFrom.parse(strDate);
      dateFormated = formatterTo.format(date);
} catch (ParseException e) {
      e.printStackTrace();
}

// Convert 2020-11-01 to Date
Date date = new SimpleDateFormat("yyyy-MM-dd").parse(sDate1);

// Get date time from Date
String dayOfTheWeek = (String) DateFormat.format("EEEE", date); // Thursday
String day          = (String) DateFormat.format("dd",   date); // 20
String monthString  = (String) DateFormat.format("MMM",  date); // Jun
String monthNumber  = (String) DateFormat.format("MM",   date); // 06
String year         = (String) DateFormat.format("yyyy", date); // 2013

// Add hours
Calendar cal = Calendar.getInstance();
cal.setTime(date);
cal.add(Calendar.HOUR_OF_DAY,2); // this will add two hours
date = cal.getTime();


// GET MIN & MAX DATE
import java.util.Calendar;
Calendar c1 = Calendar.getInstance();
c1.add(Calendar.MONTH, -1);
Date dateMin = c1.getTime(); // Tue Oct 20 16:08:44 WIB 2020

Calendar c2 = Calendar.getInstance();
c2.add(Calendar.MONTH, +1);
Date dateMax = c2.getTime(); // Sun Dec 20 16:08:44 WIB 2020

dial.java

// open keypad contact
Intent intent = new Intent(Intent.ACTION_DIAL);
intent.setData(Uri.parse("tel:9999999999"));
startActivity(intent)
  
// open twitter
Intent intent = new Intent(Intent.ACTION_VIEW);
intent.setData(Uri.parse("https://twitter.com/intent/tweet?text=%40HaloBCA+&url"));
mActivity.startActivity(intent);

// open email 
Intent intent = new Intent(Intent.ACTION_SENDTO);
intent.setData(Uri.parse("mailto:halobca@bca.co.id"));
mActivity.startActivity(intent);

// open whatsApp
Intent intent = new Intent(Intent.ACTION_VIEW);
intent.setData(Uri.parse("https://api.whatsapp.com/send?phone=6281115xxx&text=%23HaloBCA&app_absent=0"));
mActivity.startActivity(intent);

global.java

// SPINNER with VALUE & LABEL
String selectedVal = getResources().getStringArray(R.array.member_value)[spinnerType.getSelectedItemPosition()];


// SAVE OBJECT to STRING     : import com.google.gson.Gson;
MyObject myObject = new MyObject;
Gson gson = new Gson();
String json = gson.toJson(myObject);


// RETRIVE STRING to OBJECT
Gson gson = new Gson();
MyObject obj = gson.fromJson(json, MyObject.class);
log.d(obj.getName());

// inflate layout without activity or fragment
FrameLayout frame = loginActivity.findViewById(R.id.fragment_forgot);
frame.removeAllViews();
LayoutInflater.from(mContext).inflate(R.layout.otp, frame, true);

intent.java

// Fragment -> Fragment
Fragment2 fragment2 = new Fragment2();
FragmentManager fragmentManager = getFragmentManager();
FragmentTransaction fragmentTransaction = fragmentManager.beginTransaction();
fragmentTransaction.replace(R.id.container, fragment2);
fragmentTransaction.addToBackStack(null);
fragmentTransaction.commit();

// Fragment -> activity
Intent intent = new Intent(getActivity(), MainActivityList.class);
startActivity(intent);

// activity -> fragment
FragmentManager fragmentManager = getSupportFragmentManager();
        FragmentTransaction fragmentTransaction = fragmentManager.beginTransaction();
        fragmentTransaction
                .add(R.id.fragment_container, new ForgotPinFragment())
                .addToBackStack(null)
                .commit();