Krishna app worlds

RTO Exam Preparation 2026 | Driving Licence Test India

2020-04-22T10:06:00.010+05:30

RTO Exam Preparation 2026 | Driving Licence Test India

RTO Exam Preparation 2026: Gujarati, Hindi & English Driving Licence Test Guide

Preparing for the RTO driving licence test in India can be challenging if you are not familiar with traffic rules, road signs, and exam patterns. This guide will help you prepare effectively and pass your RTO exam with confidence.

🚗 What is the RTO Exam?

The RTO (Regional Transport Office) exam is required to obtain a learning licence in India. It tests your knowledge of traffic rules, road signs, and safe driving practices.

📚 How to Prepare for RTO Exam

Study traffic rules daily
Learn road signs and meanings
Practice multiple-choice questions
Take mock tests regularly
Review mistakes and improve

📱 Practice Using Mobile App

Download the app and start practicing anytime:

🚀 Download RTO Exam App

🎥 Watch Demo Video

🌐 Gujarati & English Support

This app supports both Gujarati and English languages, making it easier for users to understand and prepare effectively for the RTO exam.

🚦 Important Topics

Traffic rules and signals
Road signs and meanings
Driving safety guidelines
Penalties and regulations

⚠️ Common Mistakes to Avoid

Skipping practice tests
Ignoring road signs
Not reviewing wrong answers
Last-minute preparation

🏁 Conclusion

With proper preparation and regular practice, passing the RTO exam becomes easy. Use the app, practice daily, and stay confident.

Android SQLite Login & Register App with CRUD Operations in Java (2026)

2019-08-03T20:51:00.006+05:30

Android SQLite Login & Register App with CRUD Operations (2026) | Krishna App Worlds

Updated 2026

Android SQLite Login & Register App with Full CRUD Operations

A complete, production-ready Android project using SQLite database, SharedPreferences session management, and input validation — with full Java source code and XML layouts.

Java and Android Studio SQLite / SQLiteOpenHelper CRUD Operations Updated May 2026 Beginner-friendly

SQLite is a lightweight, serverless relational database built directly into Android. It is the ideal choice for storing structured user data locally — without requiring an internet connection. This tutorial walks you through a complete Login & Register Android application backed by SQLite, covering all four CRUD operations: Create (register), Read (login / profile), Update (edit profile), and Delete (implicit via session logout).

What You Will Build

🔐Login Screen

📝Register Screen

👤User Profile Screen

✏️Update User Screen

🗄️SQLite Database

💾Session with SharedPrefs

✅Email Validation

🔄Auto-login on relaunch

App Screenshots

▶ View on Play Store

Resource Files

values/

color.xml XML

<?xml version="1.0" encoding="utf-8"?>
<resources>
    <color name="colorPrimary">#3b5998</color>
    <color name="colorPrimaryDark">#3b5998</color>
    <color name="colorAccent">#3b5998</color>
    <color name="lavender">#3b5998</color>
    <color name="white">#FFFFFF</color>
    <color name="login_button">#D81B60</color>
</resources>

strings.xml XML

<?xml version="1.0" encoding="utf-8"?>
<resources>
    <string name="app_name">Login</string>
    <string name="email">Email</string>
    <string name="login">Login</string>
    <string name="name">Name</string>
    <string name="password">Password</string>
    <string name="phone">Phone number</string>
    <string name="register">Register</string>
    <string name="user_login">User Login</string>
    <string name="please_enter_name">Please enter name</string>
    <string name="please_enter_email">Please enter email</string>
    <string name="please_enter_password">Please enter password</string>
    <string name="please_enter_phone">Please enter phone number</string>
    <string name="loading">Loading...</string>
    <string name="ok">OK</string>
    <string name="register_success">Registration successful</string>
    <string name="email_id_use">Email address already in use</string>
    <string name="fail">Login Failed</string>
    <string name="update">Update</string>
    <string name="logout">Logout</string>
    <string name="update_user">Update User</string>
</resources>

styles.xml XML

<resources>
    <style name="AppTheme" parent="Theme.AppCompat.Light.NoActionBar">
        <item name="colorPrimary">@color/colorPrimary</item>
        <item name="colorPrimaryDark">@color/colorPrimaryDark</item>
        <item name="colorAccent">@color/colorAccent</item>
    </style>
</resources>

drawable/

edittext_bg.xml XML

<?xml version="1.0" encoding="utf-8"?>
<selector xmlns:android="http://schemas.android.com/apk/res/android">
    <item>
        <shape android:shape="rectangle">
            <stroke android:width="1dp" android:color="@color/white" />
            <corners android:radius="20dp" />
        </shape>
    </item>
</selector>

login_button_bg.xml XML

<?xml version="1.0" encoding="utf-8"?>
<selector xmlns:android="http://schemas.android.com/apk/res/android">
    <item>
        <shape android:shape="rectangle">
            <solid android:color="@color/white" />
            <corners android:radius="40dp" />
        </shape>
    </item>
</selector>

XML Layout Files

activity_login.xml XML

<?xml version="1.0" encoding="utf-8"?>
<ScrollView 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"
    android:background="@color/lavender"
    android:fillViewport="true">

    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:background="@color/lavender"
        android:gravity="center"
        android:orientation="vertical"
        tools:context=".Activity.Login">

        <TextView
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_gravity="center"
            android:text="@string/login"
            android:textColor="@color/white"
            android:textSize="32sp"
            android:textStyle="bold" />

        <EditText
            android:id="@+id/editText_email_login"
            android:layout_width="match_parent"
            android:layout_height="50dp"
            android:layout_marginStart="20dp"
            android:layout_marginTop="40dp"
            android:layout_marginEnd="20dp"
            android:background="@drawable/edittext_bg"
            android:hint="@string/email"
            android:inputType="textEmailAddress"
            android:paddingStart="10dp"
            android:paddingEnd="10dp"
            android:singleLine="true"
            android:textColor="@color/white"
            android:textColorHint="@color/white"
            android:textCursorDrawable="@null" />

        <EditText
            android:id="@+id/editText_password_login"
            android:layout_width="match_parent"
            android:layout_height="50dp"
            android:layout_marginStart="20dp"
            android:layout_marginTop="20dp"
            android:layout_marginEnd="20dp"
            android:background="@drawable/edittext_bg"
            android:hint="@string/password"
            android:inputType="textPassword"
            android:paddingStart="10dp"
            android:paddingEnd="10dp"
            android:singleLine="true"
            android:textColor="@color/white"
            android:textColorHint="@color/white"
            android:textCursorDrawable="@null" />

        <LinearLayout
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_gravity="center"
            android:orientation="horizontal">

            <Button
                android:id="@+id/button_login"
                android:layout_width="120dp"
                android:layout_height="40dp"
                android:layout_marginTop="20dp"
                android:background="@drawable/login_button_bg"
                android:text="@string/login"
                android:textColor="@color/login_button"
                android:textStyle="bold" />

            <Button
                android:id="@+id/button_reg_login"
                android:layout_width="120dp"
                android:layout_height="40dp"
                android:layout_marginStart="20dp"
                android:layout_marginTop="20dp"
                android:background="@drawable/login_button_bg"
                android:text="@string/register"
                android:textColor="@color/login_button"
                android:textStyle="bold" />

        </LinearLayout>

    </LinearLayout>

</ScrollView>

activity_register.xml XML

<?xml version="1.0" encoding="utf-8"?>
<ScrollView 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"
    android:background="@color/lavender"
    android:fillViewport="true">

    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:gravity="center"
        android:orientation="vertical"
        tools:context=".Activity.Register">

        <TextView
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_gravity="center"
            android:text="@string/register"
            android:textColor="@color/white"
            android:textSize="32sp"
            android:textStyle="bold" />

        <EditText
            android:id="@+id/editText_name_reg"
            android:layout_width="match_parent"
            android:layout_height="50dp"
            android:layout_marginStart="20dp"
            android:layout_marginTop="50dp"
            android:layout_marginEnd="20dp"
            android:background="@drawable/edittext_bg"
            android:hint="@string/name"
            android:inputType="text"
            android:paddingStart="10dp"
            android:paddingEnd="10dp"
            android:singleLine="true"
            android:textColor="@color/white"
            android:textColorHint="@color/white"
            android:textCursorDrawable="@null" />

        <EditText
            android:id="@+id/editText_email_reg"
            android:layout_width="match_parent"
            android:layout_height="50dp"
            android:layout_marginStart="20dp"
            android:layout_marginTop="20dp"
            android:layout_marginEnd="20dp"
            android:background="@drawable/edittext_bg"
            android:hint="@string/email"
            android:inputType="textEmailAddress"
            android:paddingStart="10dp"
            android:paddingEnd="10dp"
            android:singleLine="true"
            android:textColor="@color/white"
            android:textColorHint="@color/white"
            android:textCursorDrawable="@null" />

        <EditText
            android:id="@+id/editText_password_reg"
            android:layout_width="match_parent"
            android:layout_height="50dp"
            android:layout_marginStart="20dp"
            android:layout_marginTop="20dp"
            android:layout_marginEnd="20dp"
            android:background="@drawable/edittext_bg"
            android:hint="@string/password"
            android:inputType="textPassword"
            android:paddingStart="10dp"
            android:paddingEnd="10dp"
            android:singleLine="true"
            android:textColor="@color/white"
            android:textColorHint="@color/white"
            android:textCursorDrawable="@null" />

        <EditText
            android:id="@+id/editText_phone_reg"
            android:layout_width="match_parent"
            android:layout_height="50dp"
            android:layout_marginStart="20dp"
            android:layout_marginTop="20dp"
            android:layout_marginEnd="20dp"
            android:background="@drawable/edittext_bg"
            android:hint="@string/phone"
            android:inputType="phone"
            android:paddingStart="10dp"
            android:paddingEnd="10dp"
            android:singleLine="true"
            android:textColor="@color/white"
            android:textColorHint="@color/white"
            android:textCursorDrawable="@null" />

        <Button
            android:id="@+id/button_reg"
            android:layout_width="120dp"
            android:layout_height="40dp"
            android:layout_gravity="center"
            android:layout_marginTop="40dp"
            android:layout_marginBottom="40dp"
            android:background="@drawable/login_button_bg"
            android:text="@string/register"
            android:textColor="@color/login_button"
            android:textStyle="bold" />

    </LinearLayout>

</ScrollView>

activity_main.xml XML

<?xml version="1.0" encoding="utf-8"?>
<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"
    android:layout_gravity="center_vertical"
    tools:context=".Activity.MainActivity">

    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_marginStart="10dp"
        android:layout_marginTop="40dp"
        android:layout_marginEnd="10dp"
        android:orientation="vertical">

        <LinearLayout android:layout_width="wrap_content" android:layout_height="wrap_content">
            <TextView android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="@string/name" android:textSize="18sp" />
            <TextView android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_marginStart="10dp" android:layout_marginEnd="10dp" android:text=":-" android:textSize="18sp" />
            <TextView android:id="@+id/textView_name_main" android:layout_width="wrap_content" android:layout_height="wrap_content" android:textSize="18sp" />
        </LinearLayout>

        <LinearLayout android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_marginTop="10dp">
            <TextView android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="@string/email" android:textSize="18sp" />
            <TextView android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_marginStart="10dp" android:layout_marginEnd="10dp" android:text=":-" android:textSize="18sp" />
            <TextView android:id="@+id/textView_email_main" android:layout_width="wrap_content" android:layout_height="wrap_content" android:textSize="18sp" />
        </LinearLayout>

        <LinearLayout android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_marginTop="10dp">
            <TextView android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="@string/phone" android:textSize="18sp" />
            <TextView android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_marginStart="10dp" android:layout_marginEnd="10dp" android:text=":-" android:textSize="18sp" />
            <TextView android:id="@+id/textView_phone_main" android:layout_width="wrap_content" android:layout_height="wrap_content" android:textSize="18sp" />
        </LinearLayout>

        <LinearLayout android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_gravity="center" android:layout_marginTop="20dp" android:orientation="horizontal">
            <Button android:id="@+id/button_update_main" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="@string/update" />
            <Button android:id="@+id/button_logout_main" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_marginStart="5dp" android:text="@string/logout" />
        </LinearLayout>

    </LinearLayout>

</RelativeLayout>

activity_update_user.xml XML

<?xml version="1.0" encoding="utf-8"?>
<ScrollView 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"
    android:background="@color/lavender"
    android:fillViewport="true">

    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:gravity="center"
        android:orientation="vertical"
        tools:context=".Activity.UpdateUser">

        <TextView
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_gravity="center"
            android:text="@string/update_user"
            android:textColor="@color/white"
            android:textSize="32sp"
            android:textStyle="bold" />

        <EditText android:id="@+id/editText_name_update" android:layout_width="match_parent" android:layout_height="50dp" android:layout_marginStart="20dp" android:layout_marginTop="50dp" android:layout_marginEnd="20dp" android:background="@drawable/edittext_bg" android:hint="@string/name" android:inputType="text" android:paddingStart="10dp" android:paddingEnd="10dp" android:singleLine="true" android:textColor="@color/white" android:textColorHint="@color/white" android:textCursorDrawable="@null" />
        <EditText android:id="@+id/editText_email_update" android:layout_width="match_parent" android:layout_height="50dp" android:layout_marginStart="20dp" android:layout_marginTop="20dp" android:layout_marginEnd="20dp" android:background="@drawable/edittext_bg" android:hint="@string/email" android:inputType="textEmailAddress" android:paddingStart="10dp" android:paddingEnd="10dp" android:singleLine="true" android:textColor="@color/white" android:textColorHint="@color/white" android:textCursorDrawable="@null" />
        <EditText android:id="@+id/editText_password_update" android:layout_width="match_parent" android:layout_height="50dp" android:layout_marginStart="20dp" android:layout_marginTop="20dp" android:layout_marginEnd="20dp" android:background="@drawable/edittext_bg" android:hint="@string/password" android:inputType="textPassword" android:paddingStart="10dp" android:paddingEnd="10dp" android:singleLine="true" android:textColor="@color/white" android:textColorHint="@color/white" android:textCursorDrawable="@null" />
        <EditText android:id="@+id/editText_phone_update" android:layout_width="match_parent" android:layout_height="50dp" android:layout_marginStart="20dp" android:layout_marginTop="20dp" android:layout_marginEnd="20dp" android:background="@drawable/edittext_bg" android:hint="@string/phone" android:inputType="phone" android:paddingStart="10dp" android:paddingEnd="10dp" android:singleLine="true" android:textColor="@color/white" android:textColorHint="@color/white" android:textCursorDrawable="@null" />

        <Button
            android:id="@+id/button_update"
            android:layout_width="120dp"
            android:layout_height="40dp"
            android:layout_gravity="center"
            android:layout_marginTop="40dp"
            android:layout_marginBottom="40dp"
            android:background="@drawable/login_button_bg"
            android:text="@string/update"
            android:textColor="@color/login_button"
            android:textStyle="bold" />

    </LinearLayout>

</ScrollView>

AndroidManifest.xml

AndroidManifest.xml XML

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.app.databaseloginregister">

    <application
        android:allowBackup="true"
        android:icon="@mipmap/ic_launcher"
        android:label="@string/app_name"
        android:roundIcon="@mipmap/ic_launcher_round"
        android:supportsRtl="true"
        android:theme="@style/AppTheme">

        <activity android:name=".Activity.Login">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />
                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
        <activity android:name=".Activity.Register" />
        <activity android:name=".Activity.UpdateUser" />
        <activity android:name=".Activity.MainActivity" />

    </application>

</manifest>

Java Source Code

package com.app.databaseloginregister.Activity;

import android.content.Context;
import android.content.Intent;
import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.view.View;
import android.view.WindowManager;
import android.view.inputmethod.InputMethodManager;
import android.widget.Button;
import android.widget.EditText;

import com.app.databaseloginregister.DataBase.DatabaseHandler;
import com.app.databaseloginregister.R;
import com.app.databaseloginregister.Util.Method;

public class Login extends AppCompatActivity {

    private Method method;
    private DatabaseHandler db;
    private String email, password;
    private EditText editText_email, editText_password;
    private Button button_reg, button_login;
    private InputMethodManager imm;

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

        method = new Method(Login.this);
        db = new DatabaseHandler(Login.this);

        imm = (InputMethodManager) getSystemService(Context.INPUT_METHOD_SERVICE);
        getWindow().setSoftInputMode(WindowManager.LayoutParams.SOFT_INPUT_STATE_HIDDEN);

        // Auto-login if session exists
        if (method.pref.getBoolean(method.pref_login, false)) {
            String id = method.pref.getString(method.profileId, null);
            startActivity(new Intent(Login.this, MainActivity.class).putExtra("id", id));
            finishAffinity();
        }

        editText_email    = findViewById(R.id.editText_email_login);
        editText_password = findViewById(R.id.editText_password_login);
        button_login      = findViewById(R.id.button_login);
        button_reg        = findViewById(R.id.button_reg_login);

        button_login.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                email    = editText_email.getText().toString().trim();
                password = editText_password.getText().toString();
                editText_email.clearFocus();
                editText_password.clearFocus();
                imm.hideSoftInputFromWindow(editText_email.getWindowToken(), 0);
                imm.hideSoftInputFromWindow(editText_password.getWindowToken(), 0);
                login();
            }
        });

        button_reg.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                startActivity(new Intent(Login.this, Register.class));
            }
        });
    }

    private void login() {
        editText_email.setError(null);
        editText_password.setError(null);

        if (!isValidMail(email) || email.isEmpty()) {
            editText_email.requestFocus();
            editText_email.setError(getString(R.string.please_enter_email));
        } else if (password.isEmpty()) {
            editText_password.requestFocus();
            editText_password.setError(getString(R.string.please_enter_password));
        } else {
            if (!db.checkLogin(email, password)) {
                String id = db.getUserId(email);
                if (id != null) {
                    method.editor.putBoolean(method.pref_login, true);
                    method.editor.putString(method.profileId, id);
                    method.editor.apply();
                    startActivity(new Intent(Login.this, MainActivity.class).putExtra("id", id));
                    finishAffinity();
                }
            } else {
                method.alertBox(getString(R.string.fail));
            }
        }
    }

    private boolean isValidMail(String email) {
        return android.util.Patterns.EMAIL_ADDRESS.matcher(email).matches();
    }
}

package com.app.databaseloginregister.Activity;

import android.content.Context;
import android.content.Intent;
import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.view.View;
import android.view.WindowManager;
import android.view.inputmethod.InputMethodManager;
import android.widget.Button;
import android.widget.EditText;

import com.app.databaseloginregister.DataBase.DatabaseHandler;
import com.app.databaseloginregister.R;
import com.app.databaseloginregister.Util.Method;

public class Register extends AppCompatActivity {

    private Method method;
    private DatabaseHandler db;
    private Button button_register;
    private InputMethodManager imm;
    private String name, email, password, phoneNo;
    private EditText editText_name, editText_email, editText_password, editText_phoneNo;

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

        method = new Method(Register.this);
        db = new DatabaseHandler(Register.this);

        imm = (InputMethodManager) getSystemService(Context.INPUT_METHOD_SERVICE);
        getWindow().setSoftInputMode(WindowManager.LayoutParams.SOFT_INPUT_STATE_HIDDEN);

        editText_name    = findViewById(R.id.editText_name_reg);
        editText_email   = findViewById(R.id.editText_email_reg);
        editText_password= findViewById(R.id.editText_password_reg);
        editText_phoneNo = findViewById(R.id.editText_phone_reg);
        button_register  = findViewById(R.id.button_reg);

        button_register.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                name    = editText_name.getText().toString().trim();
                email   = editText_email.getText().toString().trim();
                password= editText_password.getText().toString();
                phoneNo = editText_phoneNo.getText().toString().trim();

                editText_name.clearFocus();
                editText_email.clearFocus();
                editText_password.clearFocus();
                editText_phoneNo.clearFocus();
                imm.hideSoftInputFromWindow(editText_name.getWindowToken(), 0);
                imm.hideSoftInputFromWindow(editText_email.getWindowToken(), 0);
                imm.hideSoftInputFromWindow(editText_password.getWindowToken(), 0);
                imm.hideSoftInputFromWindow(editText_phoneNo.getWindowToken(), 0);

                form();
            }
        });
    }

    private boolean isValidMail(String email) {
        return android.util.Patterns.EMAIL_ADDRESS.matcher(email).matches();
    }

    private void form() {
        editText_name.setError(null);
        editText_email.setError(null);
        editText_password.setError(null);
        editText_phoneNo.setError(null);

        if (name.isEmpty()) {
            editText_name.requestFocus();
            editText_name.setError(getString(R.string.please_enter_name));
        } else if (!isValidMail(email) || email.isEmpty()) {
            editText_email.requestFocus();
            editText_email.setError(getString(R.string.please_enter_email));
        } else if (password.isEmpty()) {
            editText_password.requestFocus();
            editText_password.setError(getString(R.string.please_enter_password));
        } else if (phoneNo.isEmpty()) {
            editText_phoneNo.requestFocus();
            editText_phoneNo.setError(getString(R.string.please_enter_phone));
        } else {
            if (db.checkEmail(email)) {
                db.addUser(name, email, password, phoneNo);

                editText_name.setText("");
                editText_email.setText("");
                editText_password.setText("");
                editText_phoneNo.setText("");

                method.alertBox(getString(R.string.register_success));
                startActivity(new Intent(Register.this, Login.class));
            } else {
                method.alertBox(getString(R.string.email_id_use));
            }
        }
    }
}

MainActivity.java Java

package com.app.databaseloginregister.Activity;

import android.content.Intent;
import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.view.View;
import android.widget.Button;
import android.widget.TextView;

import com.app.databaseloginregister.DataBase.DatabaseHandler;
import com.app.databaseloginregister.Item.UserList;
import com.app.databaseloginregister.R;
import com.app.databaseloginregister.Util.Method;

import java.util.ArrayList;
import java.util.List;

public class MainActivity extends AppCompatActivity {

    private String id;
    private Method method;
    private DatabaseHandler db;
    private List<UserList> userLists;
    private Button button_update, button_logout;

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

        id       = getIntent().getStringExtra("id");
        method   = new Method(MainActivity.this);
        userLists= new ArrayList<>();
        db       = new DatabaseHandler(MainActivity.this);
        userLists= db.getUser(id);

        TextView textView_name    = findViewById(R.id.textView_name_main);
        TextView textView_email   = findViewById(R.id.textView_email_main);
        TextView textView_phoneNo = findViewById(R.id.textView_phone_main);
        button_update = findViewById(R.id.button_update_main);
        button_logout = findViewById(R.id.button_logout_main);

        if (!userLists.isEmpty()) {
            textView_name.setText(userLists.get(0).getName());
            textView_email.setText(userLists.get(0).getEmail());
            textView_phoneNo.setText(userLists.get(0).getPhone());
        }

        button_update.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                startActivity(new Intent(MainActivity.this, UpdateUser.class)
                        .putExtra("id", id)
                        .putExtra("name", userLists.get(0).getName())
                        .putExtra("email", userLists.get(0).getEmail())
                        .putExtra("phone", userLists.get(0).getPhone()));
            }
        });

        button_logout.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                method.editor.putBoolean(method.pref_login, false);
                method.editor.apply();
                startActivity(new Intent(MainActivity.this, Login.class));
                finishAffinity();
            }
        });
    }
}

UpdateUser.java Java

package com.app.databaseloginregister.Activity;

import android.content.Context;
import android.content.Intent;
import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.view.View;
import android.view.WindowManager;
import android.view.inputmethod.InputMethodManager;
import android.widget.Button;
import android.widget.EditText;

import com.app.databaseloginregister.DataBase.DatabaseHandler;
import com.app.databaseloginregister.R;
import com.app.databaseloginregister.Util.Method;

public class UpdateUser extends AppCompatActivity {

    private Method method;
    private DatabaseHandler db;
    private Button button_update;
    private InputMethodManager imm;
    private String id, name, email, password, phoneNo;
    private EditText editText_name, editText_email, editText_password, editText_phoneNo;

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

        method  = new Method(UpdateUser.this);
        db      = new DatabaseHandler(UpdateUser.this);

        id      = getIntent().getStringExtra("id");
        name    = getIntent().getStringExtra("name");
        email   = getIntent().getStringExtra("email");
        phoneNo = getIntent().getStringExtra("phone");

        imm = (InputMethodManager) getSystemService(Context.INPUT_METHOD_SERVICE);
        getWindow().setSoftInputMode(WindowManager.LayoutParams.SOFT_INPUT_STATE_HIDDEN);

        editText_name     = findViewById(R.id.editText_name_update);
        editText_email    = findViewById(R.id.editText_email_update);
        editText_password = findViewById(R.id.editText_password_update);
        editText_phoneNo  = findViewById(R.id.editText_phone_update);
        button_update     = findViewById(R.id.button_update);

        editText_name.setText(name);
        editText_email.setText(email);
        editText_phoneNo.setText(phoneNo);

        button_update.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                name    = editText_name.getText().toString().trim();
                email   = editText_email.getText().toString().trim();
                password= editText_password.getText().toString();
                phoneNo = editText_phoneNo.getText().toString().trim();

                editText_name.clearFocus();
                editText_email.clearFocus();
                editText_password.clearFocus();
                editText_phoneNo.clearFocus();
                imm.hideSoftInputFromWindow(editText_name.getWindowToken(), 0);
                imm.hideSoftInputFromWindow(editText_email.getWindowToken(), 0);
                imm.hideSoftInputFromWindow(editText_password.getWindowToken(), 0);
                imm.hideSoftInputFromWindow(editText_phoneNo.getWindowToken(), 0);

                form();
            }
        });
    }

    private boolean isValidMail(String email) {
        return android.util.Patterns.EMAIL_ADDRESS.matcher(email).matches();
    }

    private void form() {
        editText_name.setError(null);
        editText_email.setError(null);
        editText_phoneNo.setError(null);

        if (name.isEmpty()) {
            editText_name.requestFocus();
            editText_name.setError(getString(R.string.please_enter_name));
        } else if (!isValidMail(email) || email.isEmpty()) {
            editText_email.requestFocus();
            editText_email.setError(getString(R.string.please_enter_email));
        } else if (phoneNo.isEmpty()) {
            editText_phoneNo.requestFocus();
            editText_phoneNo.setError(getString(R.string.please_enter_phone));
        } else {
            db.updateUser(id, name, email, password, phoneNo);
            startActivity(new Intent(UpdateUser.this, MainActivity.class).putExtra("id", id));
            finishAffinity();
        }
    }
}

SQLite Database Handler

The DatabaseHandler class extends SQLiteOpenHelper and handles all CRUD operations for the user table.

Method	Description
`onCreate()`	Called once on first install — creates the user table with auto-increment primary key.
`onUpgrade()`	Called when DATABASE_VERSION increases — drops and recreates the table.
`addUser()`	Inserts a new user record (name, email, password, phone) into the database.
`getUser(id)`	Returns a `List<UserList>` for the given user ID.
`updateUser()`	Updates name, email, phone, and optionally password for the given ID.
`checkEmail()`	Returns `true` if the email does NOT exist (safe to register).
`getUserId()`	Returns the row ID string for the given email address.
`checkLogin()`	Returns `false` if credentials match (login success — note inverted logic).

DatabaseHandler.java Java

package com.app.databaseloginregister.DataBase;

import android.annotation.SuppressLint;
import android.content.ContentValues;
import android.content.Context;
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteOpenHelper;
import android.util.Log;

import com.app.databaseloginregister.Item.UserList;

import java.util.ArrayList;
import java.util.List;

public class DatabaseHandler extends SQLiteOpenHelper {

    private static final int    DATABASE_VERSION    = 1;
    private static final String DATABASE_NAME       = "demo_login";
    private static final String TABLE_NAME          = "user";
    private static final String KEY_ID              = "id";
    private static final String KEY_NAME            = "name";
    private static final String KEY_EMAIL           = "user_email";
    private static final String KEY_PHONE_NUMBER    = "phone_number";
    private static final String KEY_PASSWORD        = "password";

    public DatabaseHandler(Context context) {
        super(context, DATABASE_NAME, null, DATABASE_VERSION);
    }

    @Override
    public void onCreate(SQLiteDatabase db) {
        String CREATE_TABLE = "CREATE TABLE " + TABLE_NAME + "("
                + KEY_ID            + " INTEGER PRIMARY KEY AUTOINCREMENT, "
                + KEY_NAME          + " TEXT, "
                + KEY_EMAIL         + " TEXT, "
                + KEY_PHONE_NUMBER  + " TEXT, "
                + KEY_PASSWORD      + " TEXT"
                + ")";
        db.execSQL(CREATE_TABLE);
    }

    @Override
    public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
        db.execSQL("DROP TABLE IF EXISTS " + TABLE_NAME);
        onCreate(db);
    }

    /** INSERT — add a new user */
    public void addUser(String name, String email, String password, String phone) {
        SQLiteDatabase db = this.getWritableDatabase();
        ContentValues values = new ContentValues();
        values.put(KEY_NAME, name);
        values.put(KEY_EMAIL, email);
        values.put(KEY_PHONE_NUMBER, phone);
        values.put(KEY_PASSWORD, password);
        db.insert(TABLE_NAME, null, values);
        db.close();
    }

    /** READ — fetch user by ID */
    public List<UserList> getUser(String id) {
        List<UserList> userLists = new ArrayList<>();
        String selectQuery = "SELECT * FROM " + TABLE_NAME + " WHERE " + KEY_ID + " = " + id;
        Log.d("DB_QUERY", selectQuery);

        SQLiteDatabase db = this.getWritableDatabase();
        @SuppressLint("Recycle") Cursor cursor = db.rawQuery(selectQuery, null);

        if (cursor.moveToFirst()) {
            do {
                UserList list = new UserList();
                list.setName(cursor.getString(1));
                list.setEmail(cursor.getString(2));
                list.setPhone(cursor.getString(3));
                list.setPassword(cursor.getString(4));
                userLists.add(list);
            } while (cursor.moveToNext());
        }
        return userLists;
    }

    /** UPDATE — update user profile */
    public void updateUser(String id, String name, String email, String password, String phoneNumber) {
        SQLiteDatabase db = this.getWritableDatabase();
        ContentValues values = new ContentValues();
        values.put(KEY_NAME, name);
        values.put(KEY_EMAIL, email);
        if (!password.isEmpty()) values.put(KEY_PASSWORD, password);
        if (!phoneNumber.isEmpty()) values.put(KEY_PHONE_NUMBER, phoneNumber);
        db.update(TABLE_NAME, values, KEY_ID + "=" + id, null);
    }

    /** Check login credentials — returns false on success */
    public boolean checkLogin(String userEmail, String userPassword) {
        String selectQuery = "SELECT " + KEY_ID + " FROM " + TABLE_NAME
                + " WHERE " + KEY_EMAIL + " = '" + userEmail + "'"
                + " AND " + KEY_PASSWORD + " = '" + userPassword + "'";
        Log.d("DB_QUERY", selectQuery);
        SQLiteDatabase db = this.getWritableDatabase();
        Cursor cursor = db.rawQuery(selectQuery, null);
        boolean notFound = cursor.getCount() == 0;
        cursor.close();
        return notFound;
    }

    /** Check if email is available — returns true if NOT in use */
    public boolean checkEmail(String userEmail) {
        String selectQuery = "SELECT * FROM " + TABLE_NAME + " WHERE " + KEY_EMAIL + " =?";
        SQLiteDatabase db = this.getWritableDatabase();
        @SuppressLint("Recycle") Cursor cursor = db.rawQuery(selectQuery, new String[]{userEmail});
        return cursor.getCount() == 0;
    }

    /** Get user ID by email */
    public String getUserId(String userEmail) {
        String selectQuery = "SELECT * FROM " + TABLE_NAME
                + " WHERE " + KEY_EMAIL + " = '" + userEmail + "'";
        SQLiteDatabase db = this.getWritableDatabase();
        @SuppressLint("Recycle") Cursor cursor = db.rawQuery(selectQuery, null);
        if (cursor.moveToFirst()) {
            String userId = cursor.getString(0);
            Log.d("DB_USER_ID", userId);
            return userId;
        }
        return null;
    }
}

Model & Utility Classes

UserList.java Java

package com.app.databaseloginregister.Item;

import java.io.Serializable;

public class UserList implements Serializable {

    private String name, email, phone, password;

    public UserList() {}

    public UserList(String name, String email, String phone, String password) {
        this.name     = name;
        this.email    = email;
        this.phone    = phone;
        this.password = password;
    }

    public String getName()     { return name; }
    public void setName(String name)     { this.name = name; }

    public String getEmail()    { return email; }
    public void setEmail(String email)   { this.email = email; }

    public String getPhone()    { return phone; }
    public void setPhone(String phone)   { this.phone = phone; }

    public String getPassword() { return password; }
    public void setPassword(String password) { this.password = password; }
}

Method.java Java

package com.app.databaseloginregister.Util;

import android.app.Activity;
import android.content.DialogInterface;
import android.content.SharedPreferences;
import android.support.v7.app.AlertDialog;

import com.app.databaseloginregister.R;

public class Method {

    private final Activity activity;

    public SharedPreferences pref;
    public SharedPreferences.Editor editor;
    private final String myPreference = "login";
    public final String pref_login = "pref_login";
    public final String profileId  = "profileId";

    public Method(Activity activity) {
        this.activity = activity;
        pref   = activity.getSharedPreferences(myPreference, 0);
        editor = pref.edit();
    }

    /** Display a non-cancelable alert dialog */
    public void alertBox(String message) {
        AlertDialog.Builder builder = new AlertDialog.Builder(activity);
        builder.setCancelable(false);
        builder.setMessage(message);
        builder.setPositiveButton(activity.getString(R.string.ok),
                new DialogInterface.OnClickListener() {
                    @Override
                    public void onClick(DialogInterface dialog, int which) {
                        // dismiss
                    }
                });
        builder.create().show();
    }
}

🚀 View Our Applications on Google Play

How to download whatsapp status in android source code

2019-06-11T20:56:00.007+05:30


public List imageArray = new ArrayList<>();

private String root = Environment.getExternalStorageDirectory() +"/WhatsApp/Media/.Statuses";
File file = new File(root);
imageArray=getListFiles(file)

private List getListFiles(File parentDir) {
List inFiles = new ArrayList<>();
try {
	Queue files = new LinkedList<>();
	files.addAll(Arrays.asList(parentDir.listFiles()));
	while (!files.isEmpty()) {
		File file = files.remove();
		if (file.isDirectory()) {
			files.addAll(Arrays.asList(file.listFiles()));
		} else if (file.getName().endsWith(".jpg") || file.getName().endsWith(".gif")||
			file.getName().endsWith(".mp4")) {
			inFiles.add(file);
		}
	}
} catch (Exception e) {
	Log.d("error", e.toString());
}
return inFiles;
}

Play Store Link:-click here

Instance video, image and media download

2019-04-11T21:21:00.004+05:30

App Name: Instance video image download

Welcome to Instagram media download, the ultimate tool for downloading and enjoying images and videos from social media! With our app, you can effortlessly download single or multiple images and videos, watch videos within the app, and much more. Here’s what makes our application the best choice for your media needs

Key Features:

- Easy Downloads: Quickly download images and videos with a simple click.

- Batch Downloads: Download multiple images and videos from any user post with ease.

- Mixed Media Support: Seamlessly download posts containing both images and videos.

- Instant Downloads: Use our app to instantly download images and videos from social media.

- In-App Video Player: Watch your downloaded videos directly within the app.

- Pinch-to-Zoom: Enjoy the pinch-to-zoom feature for a better image viewing experience.

- Share and Set Wallpaper: Share images and videos on any social media app or set them as your wallpaper.

- Download Progress: Monitor your download progress with percentage indicators in the status bar.

How to Use This Application:

1. Open Instance: Launch our app to get started.

2. Open the Social Media App: Navigate to the social media app and find the image or video you want to download.

3. Copy Link: Use the 'Copy Link' option on the image or video post.

4. Download: Return to Instance App and past link, view your media, share it, or set it as wallpaper. Enjoy!

User Guide:

We provide a detailed video tutorial and information within the app to help you understand how to use Instance effortlessly. Follow these simple steps and maximize your experience.

Download Instance now and enjoy your favorite images and videos anytime, anywhere!

Contact Us:

If you have any questions or need support, feel free to reach out to us via krishna.app.worlds@gmail.com.

Rate Us:

If you love Our application, please take a moment to rate us on the Play Store. Your feedback helps us improve!

Little Learners: Kids Learning App for ABC, 123, Shapes & Colors

2019-04-02T21:49:00.009+05:30

Little Learners – Kids Learning App | ABC, 123, Shapes, Colors, Drawing & Parent Dashboard

🎓 Kids Learning App

Little Learners – Kids Learning

Learn · Practice · Create · Grow

Get it on Google Play

About the App

Little Learners – Kids Learning is a fun and interactive pre-learning app designed to help young children learn essential concepts through engaging activities, games, drawing, and practice. It combines early education, interactive practice, creativity, and parent-friendly progress tracking in one simple app — helping children learn at their own pace while parents stay connected to their learning journey.

📚 Learn the basics

Strong Early-Learning Foundations

🔤

Capital ABCD (A–Z)

Learn all capital letters from A to Z

🔡

Small abcd (a–z)

Learn all small letters from a to z

🔢

Numbers (123)

Build early number recognition and counting

🔷

Shapes

Explore and recognise common shapes

🎨

Colors

Identify and name colors with ease

🍎

Fruits

Learn fruit names and pictures

🥕

Vegetables

Learn vegetable names and pictures

🌙

Light & Dark Theme

Comfortable viewing for both kids and parents

🎨 Kids Drawing

Let your child's imagination come to life with a creative drawing area.

Draw freely using different shapes and colors
Create their own pictures
Explore their creativity
Save drawings for parents to keep and view later

📝 Fun Exam & Practice

The interactive exam feature helps children test what they have learned with different question types, improving recognition, memory, and understanding.

🖼️ Image & Word Selection – See an image and select the correct word.
🔗 Match the Things – Match related images or objects.
✅ Choose the Right Answer – Select the correct option from multiple choices.

👨‍👩‍👧 Parent Dashboard

Parents can easily track their child's learning progress from one place and quickly see where their child is doing well and which subjects need more practice.

⭐ Learning points and scores
📅 Daily, weekly and monthly progress
💪 Strong learning areas
📚 Areas that need more practice
📉 Easy-to-understand progress graphs

🌟 Learning benefits

Skills Your Child Will Build

✓ Letter recognition ✓ Number recognition ✓ Shapes & colors ✓ Fruit & vegetable vocabulary ✓ Memory building ✓ Creativity & art ✓ Understanding

Made for Kids, Made for Parents Children learn at their own pace through play and practice, while parents stay connected to the learning journey with clear progress tracking.

❓ Frequently asked questions

Parents Ask Us

What does Little Learners teach?

Capital letters A–Z, small letters a–z, numbers, shapes, colors, fruits and vegetables, plus a drawing area and fun practice exams.

How do the exams work?

There are three question types: Image & Word Selection, Match the Things, and Choose the Right Answer. They help children practice recognition, memory and understanding.

How can I track my child's progress?

The Parent Dashboard shows learning points, scores, and daily, weekly and monthly progress, along with strong areas, areas needing more practice, and easy progress graphs.

Can my child save their drawings?

Yes. Kids can draw freely with different shapes and colors and save their drawings for parents to keep and view later.

Does the app have a dark mode?

Yes. You can choose between Light Mode and Dark Mode for a comfortable experience for both kids and parents.

Learn. Practice. Create. Grow. 🚀

Early education, interactive practice, creativity and parent progress tracking — all in one simple app.

Download on Google Play

How to Download WhatsApp Status

2019-04-02T21:37:00.006+05:30

Play Store Link :- click here

App Name:- Status download and share (Image,video and gif)

Love your friend status and easy to share and download

easy to download status like image,video and gif.
easy to share with social media and easy to share with your friend.
you can also download status and then after share with your friend.
You can also watch video in application player.
Image status easy to set as wallpaper and home screen in phone.
pin touch feature also available in image view

Feature
1)You can also download business status
2)Share,download,set as wallpaper
3)Delete download status permanently
4)Full view image status
5)Video status easy to watch in application

How to use this application

1)First of view status in application
2)Then after view in this application or download share and set as wallpaper and enjoy application

Source code :- click here

Privacy Policy Krishna app worlds

2018-11-19T20:11:00.006+05:30

Privacy Policy

Last Update :- 15-08-2023

Krishna app worlds built the open source applications app as an Ad Supported app. This SERVICE is provided by Krishna app worlds at no cost and is intended for use as is.

This page is used to inform visitors regarding our policies with the collection, use, and disclosure of Personal Information if anyone decided to use our Service.

If you choose to use our Service, then you agree to the collection and use of information in relation to this policy. The Personal Information that we collect is used for providing and improving the Service. We will not use or share your information with anyone except as described in this Privacy Policy.

Information Collection and Use

For a better experience, while using our Service, we may require you to provide us with certain personally identifiable information. The information that we request will be retained by us and used as described in this privacy policy.

The app does use third-party services that may collect information used to identify you.

Link to the privacy policy of third-party service providers used by the app

Google Play Services
AdMob
Google Analytics for Firebase
Firebase Crashlytics
Log Data

We want to inform you that whenever you use our Service, in a case of an error in the app we collect data and information (through third-party products) on your phone called Log Data. This Log Data may include information such as your device Internet Protocol (“IP”) address, device name, operating system version, the configuration of the app when utilizing our Service, the time and date of your use of the Service, and other statistics.

Cookies

Cookies are files with a small amount of data that are commonly used as anonymous unique identifiers. These are sent to your browser from the websites that you visit and are stored on your device's internal memory.

This Service does not use these “cookies” explicitly. However, the app may use third-party code and libraries that use “cookies” to collect information and improve their services. You have the option to either accept or refuse these cookies and know when a cookie is being sent to your device. If you choose to refuse our cookies, you may not be able to use some portions of this Service.

Service Providers

We may employ third-party companies and individuals due to the following reasons:

To facilitate our Service;
To provide the Service on our behalf;
To perform Service-related services; or
To assist us in analyzing how our Service is used.
We want to inform users of this Service that these third parties have access to their Personal Information. The reason is to perform the tasks assigned to them on our behalf. However, they are obligated not to disclose or use the information for any other purpose.

Security

We value your trust in providing us your Personal Information, thus we are striving to use commercially acceptable means of protecting it. But remember that no method of transmission over the internet, or method of electronic storage is 100% secure and reliable, and we cannot guarantee its absolute security.

Links to Other Sites

This Service may contain links to other sites. If you click on a third-party link, you will be directed to that site. Note that these external sites are not operated by us. Therefore, we strongly advise you to review the Privacy Policy of these websites. We have no control over and assume no responsibility for the content, privacy policies, or practices of any third-party sites or services.

Children’s Privacy

These Services do not address anyone under the age of 13. We do not knowingly collect personally identifiable information from children under 13 years of age. In the case we discover that a child under 13 has provided us with personal information, we immediately delete this from our servers. If you are a parent or guardian and you are aware that your child has provided us with personal information, please contact us so that we will be able to do the necessary actions.

Changes to This Privacy Policy

We may update our Privacy Policy from time to time. Thus, you are advised to review this page periodically for any changes. We will notify you of any changes by posting the new Privacy Policy on this page.

The terms of condition used in the same meaning Privacy Policy .which is accessible at krishna app worlds unless otherwise defined in this Privacy Policy.

Krishna application follow the rule of GDPR(General Data Protection Regulation)

If you any query then feel free to contact krishna.app.worlds@gmail.com