Android | Working with Vector Assets and E-Mail Validation

1. activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical"
tools:context=".MainActivity">

<EditText
android:id="@+id/etusername"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_margin="10dp"
android:drawableLeft="@drawable/email"
android:drawablePadding="10dp"
android:hint="Username"
android:inputType="textEmailAddress"
android:textSize="20sp"
android:textStyle="bold" />

<EditText
android:id="@+id/etpasswd"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_margin="10dp"
android:drawableLeft="@drawable/passwd"
android:drawablePadding="10dp"
android:hint="Password"
android:inputType="textWebPassword"
android:textSize="20sp"
android:textStyle="bold" />

<Button
android:id="@+id/btnsave"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_margin="10dp"
android:text="Save"
android:textSize="20sp"
android:textStyle="bold" />


</LinearLayout>

2. MainActivity.java

package com.example.yt_vectorandemailvalidation;

import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.Toast;

public class MainActivity extends AppCompatActivity {

EditText etusername, etpasswd;
Button btnsave;
String emailPattern = "[a-zA-Z0-9._-]+@[a-z]+\\.+[a-z]+";

@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);

etusername = findViewById(R.id.etusername);
etpasswd = findViewById(R.id.etpasswd);
btnsave = findViewById(R.id.btnsave);

btnsave.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
if (etusername.getText().toString().length() != 0 && etpasswd.getText().toString().length() != 0) {
if (etusername.getText().toString().matches(emailPattern)) {
Toast.makeText(MainActivity.this, "Login Successfully", Toast.LENGTH_SHORT).show();
} else {
etusername.setError("Invalid Email");
}
} else {
etusername.setError("Username Required");
etpasswd.setError("Password Required");
}
}
});
}
}

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