How should I validate an e-mail address?

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What's a good technique for validating an e-mail address (e.g. from a user input field) in Android? org.apache.commons.validator.routines.EmailValidator doesn't seem to be available. Are there any other libraries doing this which are included in Android already or would I have to use RegExp?

36 Answers

Since API 8 (android 2.2) there is a pattern: android.util.Patterns.EMAIL_ADDRESS http://developer.android.com/reference/android/util/Patterns.html

So you can use it to validate yourEmailString:

private boolean isValidEmail(String email) {
    Pattern pattern = Patterns.EMAIL_ADDRESS;
    return pattern.matcher(email).matches();
}

returns true if the email is valid

UPD: This pattern source code is:

public static final Pattern EMAIL_ADDRESS
    = Pattern.compile(
        "[a-zA-Z0-9\\+\\.\\_\\%\\-\\+]{1,256}" +
        "\\@" +
        "[a-zA-Z0-9][a-zA-Z0-9\\-]{0,64}" +
        "(" +
            "\\." +
            "[a-zA-Z0-9][a-zA-Z0-9\\-]{0,25}" +
        ")+"
    );

refer to: http://grepcode.com/file/repository.grepcode.com/java/ext/com.google.android/android/2.2_r1.1/android/util/Patterns.java

So you can build it yourself for compatibility with API < 8.

You could write a Kotlin extension like this:

fun String.isValidEmail() =
        isNotEmpty() && android.util.Patterns.EMAIL_ADDRESS.matcher(this).matches()

And then call it like this:

email.isValidEmail()

This is Android Studio suggestions:

public static boolean isEmailValid(String email) {
    return !(email == null || TextUtils.isEmpty(email)) && android.util.Patterns.EMAIL_ADDRESS.matcher(email).matches();
}

There is a Patterns class in package android.util which is beneficial here. Below is the method I always use for validating email and many other stuffs

private boolean isEmailValid(String email) {
    return !TextUtils.isEmpty(email) && Patterns.EMAIL_ADDRESS.matcher(email).matches();
}

this is the best way in kotlin Useing Extension Function

fun String.isEmailValid(): Boolean {
        return !TextUtils.isEmpty(this) && android.util.Patterns.EMAIL_ADDRESS.matcher(this).matches()
    }

Simplest Kotlin solution using extension functions:

fun String.isEmailValid() =
            Pattern.compile(
                    "[a-zA-Z0-9\\+\\.\\_\\%\\-\\+]{1,256}" +
                            "\\@" +
                            "[a-zA-Z0-9][a-zA-Z0-9\\-]{0,64}" +
                            "(" +
                            "\\." +
                            "[a-zA-Z0-9][a-zA-Z0-9\\-]{0,25}" +
                            ")+"
            ).matcher(this).matches()

and then you can validate like this:

"testemail6589@gmail.com".isEmailValid()

If you are in kotlin-multiplatform without access to Pattern, this is the equivalent:

fun String.isValidEmail() = Regex(emailRegexStr).matches(this)

Validate your email address format. Ex-virag@gmail.com

public boolean emailValidator(String email) 
{
    Pattern pattern;
    Matcher matcher;
    final String EMAIL_PATTERN = "^[_A-Za-z0-9-]+(\\.[_A-Za-z0-9-]+)*@[A-Za-z0-9]+(\\.[A-Za-z0-9]+)*(\\.[A-Za-z]{2,})$";
    pattern = Pattern.compile(EMAIL_PATTERN);
    matcher = pattern.matcher(email);
    return matcher.matches();
}

Here is android.util.Patterns.EMAIL_ADDRESS

[a-zA-Z0-9+._\%-+]{1,256}\@[a-zA-Z0-9][a-zA-Z0-9-]{0,64}(.[a-zA-Z0-9][a-zA-Z0-9-]{0,25})+

String will match it if

Start by 1->256 character in (a-z, A-Z, 0-9, +, ., _, %, - , +)  
then 1 '@' character  
then 1 character in (a-z, A-Z, 0-9)  
then 0->64 character in (a-z, A-Z, 0-9, -)  
then **ONE OR MORE** 
         1 '.' character   
    then 1 character in (a-z, A-Z, 0-9)   
    then 0->25 character in (a-z, A-Z, 0-9, -)

Example some special match email

a@b.c
a+@b-.c
a@b.c.d.e.f.g.h

You may modify this pattern for your case then validate by

fun isValidEmail(email: String): Boolean {
    return Patterns.EMAIL_ADDRESS.matcher(email).matches()
}

Following was used by me. However it contains extra characters than normal emails but this was a requirement for me.

public boolean isValidEmail(String inputString) {
    String  s ="^((?!.*?\.\.)[A-Za-z0-9\.\!\#\$\%\&\'*\+\-\/\=\?\^_`\{\|\}\~]+@[A-Za-z0-9]+[A-Za-z0-9\-\.]+\.[A-Za-z0-9\-\.]+[A-Za-z0-9]+)$";
    Pattern pattern = Pattern.compile(regex);
    Matcher matcher = pattern.matcher(inputString);
    return matcher.matches();
}

Answer of this question:- Requirement to validate an e-mail address with given points

Explanation-

  1. (?!.*?..) "Negative Lookhead" to negate 2 consecutive dots.
  2. [A-Za-z0-9.!#\$\%\&\'*+-/\=\?\^_`{\|}\~]+ Atleast one characters defined. ("\" is used for escaping).
  3. @ There might be one "@".
  4. [A-Za-z0-9]+ then atleast one character defined.
  5. [A-Za-z0-9-.]* Zero or any repetition of character defined.
  6. [A-Za-z0-9]+ Atleast one char after dot.

The key here is that you want to fully validate the email address. You don’t just want to check it for syntactic correctness, you want to check whether the email address is real.

Two obvious reasons: real users often mis-type their email addresses, and some users may put in fake email addresses. Therefore, you want to do a syntactic check and an existence check.

The best way to do this that I have found on Android is to use the free Cloudmersive Validation API for this.

The code looks like this:

ApiClient defaultClient = Configuration.getDefaultApiClient();

// Configure API key authorization: Apikey
ApiKeyAuth Apikey = (ApiKeyAuth) defaultClient.getAuthentication("Apikey");
Apikey.setApiKey("YOUR API KEY");

EmailApi apiInstance = new EmailApi();
String email = "email_example"; // String | Email address to validate, e.g. \"support@cloudmersive.com\". The input is a string so be sure to enclose it in double-quotes.
try {
    FullEmailValidationResponse result = apiInstance.emailFullValidation(email);
    System.out.println(result);
} catch (ApiException e) {
    System.err.println("Exception when calling EmailApi#emailFullValidation");
    e.printStackTrace();
}

I’m using this in all my apps and it is great because I can validate the email addresses in the UX at the point of entry.

According to Patterns.EMAIL_ADDRESS, this email is correct "abc@abc.c". So I modified the regex in Patterns.EMAIL_ADDRESS and increased the minimum length for domain. Here is the function for Kotlin:

fun isEmailValid(email: String): Boolean =
    email.isNotEmpty() && Pattern.compile(
        "[a-zA-Z0-9\\+\\.\\_\\%\\-\\+]{1,256}" +
                "\\@" +
                "[a-zA-Z0-9][a-zA-Z0-9\\-]{0,64}" +
                "(" +
                "\\." +
                "[a-zA-Z0-9][a-zA-Z0-9\\-]{1,25}" +
                ")+"
    ).matcher(email).matches()

I just changed domain part from {0,25} to {1,25}.

I have used follwing code.This works grate.I hope this will help you.

if (validMail(yourEmailString)){
   //do your stuf
 }else{
 //email is not valid.
}

and use follwing method.This returns true if email is valid.

    private boolean validMail(String yourEmailString) {
    Pattern emailPattern = Pattern.compile(".+@.+\\.[a-z]+");
    Matcher emailMatcher = emailPattern.matcher(emailstring);
    return emailMatcher.matches();
}

I know that It's very too late, still I will give my answer.

I used this line of code to check the inputted Email format:

!TextUtils.isEmpty(getEmail) && android.util.Patterns.EMAIL_ADDRESS.matcher(getEmail).matches();

The problem is, it will only check for the FORMAT not the SPELLING.

When I entered @gmal.com missing i ,and @yaho.com missing another o . It return true. Since it satisfies the condition for Email Format.

What I did is, I used the code above. Since it will give / return true if the if the user inputted @gmail.com ONLY, no text at the start.

FORMAT CHECKER

check

If I enter this email it will give me: true but the spelling is wrong. In my textInputLayout error

wrongSpelling

EMAIL ADDRESS @yahoo.com , @gmail.com, @outlook.com CHECKER

 //CHECK EMAIL
public boolean checkEmailValidity(AppCompatEditText emailFormat){

    String getEmail = emailFormat.getText().toString();
    boolean getEnd;

    //CHECK STARTING STRING IF THE USER
    //entered @gmail.com / @yahoo.com / @outlook.com only
    boolean getResult = !TextUtils.isEmpty(getEmail) && android.util.Patterns.EMAIL_ADDRESS.matcher(getEmail).matches();

    //CHECK THE EMAIL EXTENSION IF IT ENDS CORRECTLY
    if (getEmail.endsWith("@gmail.com") || getEmail.endsWith("@yahoo.com") || getEmail.endsWith("@outlook.com")){
        getEnd = true;
    }else {
        getEnd = false;
    }

    //TEST THE START AND END
    return (getResult && getEnd);
}

RETURN: false

false

noSpecial

RETURN:true

true

XML:

<android.support.v7.widget.AppCompatEditText
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:id="@+id/editTextEmailAddress"
            android:inputType="textEmailAddress|textWebEmailAddress"
            android:cursorVisible="true"
            android:focusable="true"
            android:focusableInTouchMode="true"
            android:singleLine="true"
            android:maxLength="50"
            android:theme="@style/EditTextCustom"/>

Note: I tried to get the value from EditText and used split on it and even StringTokenizer. Both return false to me.

Email Validation in Kotlin:

val email = etEmail.text.toString().trim() // get email from user

  if(isValidEmail(email)){ // call isValidEmail function and pass email in parameter
      // Your email ID is Valid
  }else{
      // Enter your valid email ID
  }

This method is used for checking valid email id formats.

    fun isValidEmail(email: CharSequence): Boolean {
        var isValid = true
        val expression = "^[\\w.-]+@([\\w\\-]+\\.)+[A-Z]{2,4}$"
        val pattern = Pattern.compile(expression, Pattern.CASE_INSENSITIVE)
        val matcher = pattern.matcher(email)
        if (!matcher.matches()) {
            isValid = false
        }
        return isValid
    }

Simplest way of Email Validation.

EditText TF;
public Button checkButton;

public final Pattern EMAIL_ADDRESS_PATTERN = Pattern.compile(
          "[a-zA-Z0-9+._%-+]{1,256}" +
          "@" +
          "[a-zA-Z0-9][a-zA-Z0-9-]{0,64}" +
          "(" +
          "." +
          "[a-zA-Z0-9][a-zA-Z0-9-]{0,25}" +
          ")+"
      );
 @Override
 public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    requestWindowFeature(Window.FEATURE_NO_TITLE);
    setContentView(R.layout.main);

   TF=(EditText) findViewById(R.id.TF);
   checkButton=(Button) findViewById(R.id.checkButton);

    checkButton.setOnClickListener(new OnClickListener() {
    public void onClick(View v) {
           String email=TF.getText().toString();
           if(checkEmail(email))
              Toast.makeText(getApplicationContext(),"Valid Email Addresss", Toast.LENGTH_SHORT).show();
           else
              Toast.makeText(getApplicationContext(),"Invalid Email Addresss", Toast.LENGTH_SHORT).show();
    }
    });
}
private boolean checkEmail(String email) {
    return EMAIL_ADDRESS_PATTERN.matcher(email).matches();
}}

Kotlin Extension Function

fun EditText.isValidEmail() : Boolean{
    return if(Pattern
            .compile("^[_A-Za-z0-9-]+(\\.[_A-Za-z0-9-]+)*@[A-Za-z0-9]+(\\.[A-Za-z0-9]+)*(\\.[A-Za-z]{2,})$")
            .matcher(text.toString()).matches()){
        true
    }else {
        hint = context.getString(R.string.invalid_email_adress)
        false
    }
}

Use

if(!emailEt.isValidEmail()){
    return
}
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