Validate an email inside an EditText [duplicate]

问题

I want to validate an email introduced inside an EditText and this the code that I already have:

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

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

    textMessage.addTextChangedListener(new TextWatcher() { 
        public void afterTextChanged(Editable s) { 
            if (textMessage.getText().toString().matches("[a-zA-Z0-9._-]+@[a-z]+.[a-z]+") && s.length() > 0)
            {
                text.setText("valid email");
            }
            else
            {
                text.setText("invalid email");
            }
        } 
        public void beforeTextChanged(CharSequence s, int start, int count, int after) {} 
        public void onTextChanged(CharSequence s, int start, int before, int count) {} 
    });

The problem is that when I introduce 3 characters after the "@", it appears the message "valid email", when it must appear when I introduce the complete email.

Any suggerence?

Thank you all!

回答1:

Just change your regular expression as follows:

"[a-zA-Z0-9._-]+@[a-z]+\\.+[a-z]+"

Because . (dot) means match any single-char.ADD a double backslash before your dot to stand for a real dot.

回答2:

I wrote a library that extends EditText which supports natively some validation methods and is actually very flexible.

Current, as I write, natively supported (through xml attributes) validation methods are:

regexp: for custom regexp
numeric: for an only numeric field
alpha: for an alpha only field
alphaNumeric: guess what?
email: checks that the field is a valid email
creditCard: checks that the field contains a valid credit card using Luhn Algorithm
phone: checks that the field contains a valid phone number
domainName: checks that field contains a valid domain name ( always passes the test in API Level < 8 )
ipAddress: checks that the field contains a valid ip address webUrl: checks that the field contains a valid url ( always passes the test in API Level < 8 )
nocheck: It does not check anything. (Default)

You can check it out here: https://github.com/vekexasia/android-form-edittext

Hope you enjoy it :)

In the page I linked you'll be able to find also an example for email validation. I'll copy the relative snippet here:

<com.andreabaccega.widget.FormEditText
       style="@android:style/Widget.EditText"
       whatever:test="email"
       android:id="@+id/et_email"
       android:layout_width="match_parent"
       android:layout_height="wrap_content"
       android:hint="@string/hint_email"
       android:inputType="textEmailAddress"
       />

There is also a test app showcasing the library possibilities.

This is a screenshot of the app validating the email field.

回答3:

public boolean validateEmail(String email) {

Pattern pattern;
Matcher matcher;
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();

}

回答4:

If you are using API 8 or above, you can use the readily available Patterns class to validate email. Sample code:

public final static boolean isValidEmail(CharSequence target) {
    if (target == null) {
        return false;
    } else {
        return android.util.Patterns.EMAIL_ADDRESS.matcher(target).matches();
    }
}

By chance if you are even supporting API level less than 8, then you can simply copy the Patterns.java file into your project and reference it. You can get the source code for Patterns.java from this link

回答5:

Several good options here including android.util.Patterns.EMAIL_ADDRESS for API 8+.

https://stackoverflow.com/a/7882950/1011746

回答6:

Don't do it in code. You can use inputType attribute of EditText.

    <EditText 
        android:id="@+id/edit_text"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:inputType="textEmailAddress"/>

回答7:

Try this pattern.....

editText.addTextChangedListener(new TextWatcher() {

        @Override
        public void afterTextChanged(Editable s) {
            pattern = Pattern.compile(".+@.+\\.[a-z]+");
            matcher = pattern.matcher(editText.getText().toString());

            if(matcher.matches()) {
                Log.i("Test","--------Valid Email--------");
            }else {

                Log.i("Test","--------Invalid Email------");
            }
        }

        @Override
        public void beforeTextChanged(CharSequence s, int start, int count, int after) {

        }

        @Override
        public void onTextChanged(CharSequence s, int start, int before, int count) {

        } 
    });

回答8:

private boolean validateEmailAddress(CharSequence emailAddress)
{

  if( Build.VERSION.SDK_INT >= 8 )
  {
    return android.util.Patterns.EMAIL_ADDRESS.matcher(emailAddress).matches();
  }

  Pattern pattern;
  Matcher matcher;
  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(emailAddress);

  return matcher.matches();
}

回答9:

// validate your email address format. Ex-abci@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();
}

来源：https://stackoverflow.com/questions/7625862/validate-an-email-inside-an-edittext

标签

android

regex

android-edittext