Validation for a cell number in Android

Question

I have a UI where user enters the cell number and the number is stored in a string variable and then its stored into the database.

I want to validate the string to check whether the string does not contain any characters.

How do I do that?

Below is the string code.

EditText editText3 = (EditText) this.findViewById(R.id.editText2);
setNum = editText3.getText().toString(); //setNum would contain something link 8081124589

Answer 1

To validate a string, use

if (setNum.matches(regexStr))

where regexStr can be:

//matches numbers only
String regexStr = "^[0-9]*$"

//matches 10-digit numbers only
String regexStr = "^[0-9]{10}$"

//matches numbers and dashes, any order really.
String regexStr = "^[0-9\\-]*$"

//matches 9999999999, 1-999-999-9999 and 999-999-9999
String regexStr = "^(1\\-)?[0-9]{3}\\-?[0-9]{3}\\-?[0-9]{4}$"

---

There's a very long regex to validate phones in the US (7 to 10 digits, extensions allowed, etc.). The source is from this answer: A comprehensive regex for phone number validation

String regexStr = "^(?:(?:\\+?1\\s*(?:[.-]\\s*)?)?(?:\\(\\s*([2-9]1[02-9]|[2-9][02-8]1|[2-9][02-8][02-9])\\s*\\)|([2-9]1[02-9]|[2-9][02-8]1|[2-9][02-8][02-9]))\\s*(?:[.-]\\s*)?)?([2-9]1[02-9]|[2-9][02-9]1|[2-9][02-9]{2})\\s*(?:[.-]\\s*)?([0-9]{4})(?:\\s*(?:#|x\\.?|ext\\.?|extension)\\s*(\\d+))?$"

Answer 2

For API level 8 or above :

public static final boolean isValidPhoneNumber(CharSequence target) {
    if (target == null || TextUtils.isEmpty(target)) {
        return false;
    } else {
        return android.util.Patterns.PHONE.matcher(target).matches();
    }
}

Answer 3

I like to use PhoneNumberUtils. Specifically - formatNumber(String num, String defaultCountryIso). formatNumber(); will return null if it is an invalid number after attempting to format it. Otherwise, it will return the formatted string.

Example:

 EditText editText3 = (EditText) this.findViewById(R.id.editText2);
 String setNum;

 if(!TextUtils.isEmpty(editText3.getText()){
      setNum = editText3.getText.toString();

      /* format with PhoneNumberUtils */
      TelephonyManager telephonyManager = (TelephonyManager) context.getSystemService(Context.TELEPHONY_SERVICE);
      String mCountryCode = telephonyManager.getNetworkCountryIso();

      // I like to check for sdk cause less than 21 won't support default country code
      if (android.os.Build.VERSION.SDK_INT >= 21) {
          setNum = PhoneNumberUtils.formatNumber(phoneNumber, mCountryCode);
       } else {
          // this one is deprecated
          setNum = PhoneNumberUtils.formatNumber(phoneNumber);
       }

      // if setNum is not null, you now have a valid formatted number
      if(setNum != null){
         return true;
      } else {
         editText3.setError("Invalid phone number");
         Log.d(TAG, "Invalid phone number: " + setNum); 
         return false;
      }
 } else {
    return false;
 }

Also, you may need permission for the TelephonyManager [not too sure? need link]. If so, add this to the manifest:

<uses-permission android:name="android.permission.READ_PHONE_STATE"/>

Answer 4

if you simply want to test if its a number you could do try{Integer.parseInt(setNum); keep going} catch (Exception e) {oops not a number}

or Double.parseDouble(setNum); depending on what kind of number you are expecting.

or you could remove whitespace first then do the above.

or you could use a regex but thats likely overkill.

but perhaps you should be limiting the characters allowed in the edittext in the firstplace. in the xml file you could add the property android:digits="0123456789-()" for example.

you could also try to pre-populate the phone number if you are trying to get the phone number of the device the app is installed on:

TelephonyManager tMgr =(TelephonyManager)mAppContext.getSystemService(Context.TELEPHONY_SERVICE);
  mPhoneNumber = tMgr.getLine1Number();

and uses-permission android:name="android.permission.READ_PHONE_STATE".

note this doesn't always work (see Programmatically obtain the phone number of the Android phone)

Answer 5

You can use a regex like one of the repliers already stated. To route the violation message to the component one can use the setError message;

TextView v = (TextView) view;
setError(message);

This is the standard technique marking a UI component having an error. It has been leveraged inside the BARACUS Framework for Android application in order to have declarative form validation in android.

Since the stuff is Apache 2 licensed, feel free to verbatim the code.

Answer 6

You can use a regex pattern to validate the phone number format.

Considering these facts about phone number format:-

1. Country Code prefix starts with ‘+’ and has 1 to 3 digits
2. Last part of the number, also known as subscriber number is 4 digits in all of the numbers
3. Most of the countries have 10 digits phone number after excluding country code. A general observation is that all countries phone number falls somewhere between 8 to 11 digits after excluding country code.

String allCountryRegex = "^(\\+\\d{1,3}( )?)?((\\(\\d{1,3}\\))|\\d{1,3})[- .]?\\d{3,4}[- .]?\\d{4}$";

Let's break the regex and understand,

• ^ start of expression
• (\\+\\d{1,3}( )?)? is optional match of country code between 1 to 3 digits prefixed with '+' symbol, followed by space or no space.
• ((\\(\\d{1,3}\\))|\\d{1,3} is mandatory group of 1 to 3 digits with or without parenthesis followed by hyphen, space or no space.
• \\d{3,4}[- .]? is mandatory group of 3 or 4 digits followed by hyphen, space or no space
• \\d{4} is mandatory group of last 4 digits
• $ end of expression

This regex pattern matches most of the countries phone number format including these:-

        String Afghanistan      = "+93 30 539-0605";
        String Australia        = "+61 2 1255-3456";
        String China            = "+86 (20) 1255-3456";
        String Germany          = "+49 351 125-3456";
        String India            = "+91 9876543210";
        String Indonesia        = "+62 21 6539-0605";
        String Iran             = "+98 (515) 539-0605";
        String Italy            = "+39 06 5398-0605";
        String NewZealand       = "+64 3 539-0605";
        String Philippines      = "+63 35 539-0605";
        String Singapore        = "+65 6396 0605";
        String Thailand         = "+66 2 123 4567";
        String UK               = "+44 141 222-3344";
        String USA              = "+1 (212) 555-3456";
        String Vietnam          = "+84 35 539-0605";

Source:https://codingnconcepts.com/java/java-regex-for-phone-number/