Email Address Validation in Android on EditText

Java:

public static boolean isValidEmail(CharSequence target) {
    return (!TextUtils.isEmpty(target) && Patterns.EMAIL_ADDRESS.matcher(target).matches());
}

Kotlin:

fun CharSequence?.isValidEmail() = !isNullOrEmpty() && Patterns.EMAIL_ADDRESS.matcher(this).matches()

Edit: It will work On Android 2.2+ onwards !!

Edit: Added missing ;

To perform Email Validation we have many ways,but simple & easiest way are two methods.

1- Using EditText(....).addTextChangedListener which keeps triggering on every input in an EditText box i.e email_id is invalid or valid

/**
 * Email Validation ex:- [email protected]
*/


final EditText emailValidate = (EditText)findViewById(R.id.textMessage); 

final TextView textView = (TextView)findViewById(R.id.text); 

String email = emailValidate.getText().toString().trim();

String emailPattern = "[a-zA-Z0-9._-]+@[a-z]+\\.+[a-z]+";

emailValidate .addTextChangedListener(new TextWatcher() { 
    public void afterTextChanged(Editable s) { 

    if (email.matches(emailPattern) && s.length() > 0)
        { 
            Toast.makeText(getApplicationContext(),"valid email address",Toast.LENGTH_SHORT).show();
            // or
            textView.setText("valid email");
        }
        else
        {
             Toast.makeText(getApplicationContext(),"Invalid email address",Toast.LENGTH_SHORT).show();
            //or
            textView.setText("invalid email");
        }
    } 
    public void beforeTextChanged(CharSequence s, int start, int count, int after) {
    // other stuffs 
    } 
    public void onTextChanged(CharSequence s, int start, int before, int count) {
    // other stuffs 
    } 
}); 

2- Simplest method using if-else condition. Take the EditText box string using getText() and compare with pattern provided for email. If pattern doesn't match or macthes, onClick of button toast a message. It ll not trigger on every input of an character in EditText box . simple example shown below.

final EditText emailValidate = (EditText)findViewById(R.id.textMessage); 

final TextView textView = (TextView)findViewById(R.id.text); 

String email = emailValidate.getText().toString().trim();

String emailPattern = "[a-zA-Z0-9._-]+@[a-z]+\\.+[a-z]+";

// onClick of button perform this simplest code.
if (email.matches(emailPattern))
{
Toast.makeText(getApplicationContext(),"valid email address",Toast.LENGTH_SHORT).show();
}
else 
{
Toast.makeText(getApplicationContext(),"Invalid email address", Toast.LENGTH_SHORT).show();
}

I did this way:

Add this method to check whether email address is valid or not:

private boolean isValidEmailId(String email){

    return Pattern.compile("^(([\\w-]+\\.)+[\\w-]+|([a-zA-Z]{1}|[\\w-]{2,}))@"
              + "((([0-1]?[0-9]{1,2}|25[0-5]|2[0-4][0-9])\\.([0-1]?"
              + "[0-9]{1,2}|25[0-5]|2[0-4][0-9])\\."
              + "([0-1]?[0-9]{1,2}|25[0-5]|2[0-4][0-9])\\.([0-1]?"
              + "[0-9]{1,2}|25[0-5]|2[0-4][0-9])){1}|"
              + "([a-zA-Z]+[\\w-]+\\.)+[a-zA-Z]{2,4})$").matcher(email).matches();
     }

Now check with String of EditText:

if(isValidEmailId(edtEmailId.getText().toString().trim())){
  Toast.makeText(getApplicationContext(), "Valid Email Address.", Toast.LENGTH_SHORT).show();
}else{       
  Toast.makeText(getApplicationContext(), "InValid Email Address.", Toast.LENGTH_SHORT).show();
}

Done