Unique Contacts by phone number android - contacts

Question

How to filter contacts by mobile number like chat applications. If a mobile number saved in contacts database with twice by with country code and without country code. I need to merge two numbers as single contact.
For example,
I saved a contact Bala with 9876543210 and [phone]. In this scenario i need to filter both numbers and return [phone] number to my app database.

Answer 1

You need to convert all phone numbers to E164 format (with country code, no spaces or dashes)
e.g: [phone]
If you're targeting API level 21 and above, you can simply do:
String e164 = PhoneNumberUtils.formatNumberToE164(originalNumber, countryCode);
To get the country code, try this:
TelephonyManager telephony = (TelephonyManager) getSystemService(Context.TELEPHONY_SERVICE);
String countryCode = telephony.getSimCountryIso().toUpperCase();
If you're targeting api level below 21, you can use google' libphonenumber library for Android with a similar API.
If all phones are normalized into E164 format, you can remove duplicates by simply not adding a new phone to a contact in case that contact already has that phone (you might find HashMap useful for this)