**Please follow the following Steps**
Seet - 1
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context=".MainActivity" >
<EditText
android:id="@+id/editText_email"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_marginLeft="20dp"
android:layout_marginRight="20dp"
android:layout_below="@+id/textView_email"
android:layout_marginTop="40dp"
android:hint="Email Adderess"
android:inputType="textEmailAddress" />
<TextView
android:id="@+id/textView_email"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentTop="true"
android:layout_centerHorizontal="true"
android:layout_marginTop="30dp"
android:text="Email Validation Example" />
</RelativeLayout>
Seet - 2
import android.app.Activity;
import android.os.Bundle;
import android.text.Editable;
import android.text.TextWatcher;
import android.widget.EditText;
Seet - 3
public class MainActivity extends Activity {
private EditText email;
private String valid_email;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
initilizeUI();
}
/**
* This method is used to initialize UI Components
*/
private void initilizeUI() {
// TODO Auto-generated method stub
email = (EditText) findViewById(R.id.editText_email);
email.addTextChangedListener(new TextWatcher() {
@Override
public void onTextChanged(CharSequence s, int start, int before,
int count) {
// TODO Auto-generated method stub
}
@Override
public void beforeTextChanged(CharSequence s, int start, int count,
int after) {
// TODO Auto-generated method stub
}
@Override
public void afterTextChanged(Editable s) {
// TODO Auto-generated method stub
// TODO Auto-generated method stub
Is_Valid_Email(email); // pass your EditText Obj here.
}
public void Is_Valid_Email(EditText edt) {
if (edt.getText().toString() == null) {
edt.setError("Invalid Email Address");
valid_email = null;
} else if (isEmailValid(edt.getText().toString()) == false) {
edt.setError("Invalid Email Address");
valid_email = null;
} else {
valid_email = edt.getText().toString();
}
}
boolean isEmailValid(CharSequence email) {
return android.util.Patterns.EMAIL_ADDRESS.matcher(email)
.matches();
} // end of TextWatcher (email)
});
}
}