Android App Development

Welcome to our company!We build custom, scalable Android applications with modern tools like Java, XML, SQLite, Firebase, and Android Studio.

Android Studio

Android Studio is Google’s official Integrated Development Environment (IDE) for Android app development. Built on IntelliJ IDEA, it allows developers to create apps using Java, Kotlin, or C++.

What you can do with it:

• Develop Android apps: Build, design, and test mobile applications.
• UI Design: Create app interfaces with drag-and-drop features.
• Coding & Debugging: Write code efficiently and debug errors easily.
• Use Emulator: Run and test apps without a real device.
• Project Management: Manage libraries and dependencies via Gradle.

XML in Android

What is XML:

XML (eXtensible Markup Language) is a markup language used to describe data and structure. In Android, XML is mainly used for UI (User Interface) design.

What you can do with XML in Android:

1. Create UI Elements:

Define widgets like TextView, Button, ImageView, EditText, etc.

Example:

<TextView
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:text="Hello Android!"
    android:textSize="18sp"
    android:textColor="#000000"/>
    

2. Design Layouts:

Arrange elements on the screen using layouts:

• LinearLayout → vertical/horizontal arrangement
• RelativeLayout → elements positioned relative to each other
• ConstraintLayout → flexible and modern UI design

Example:

<LinearLayout
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical">
    
    <Button
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Click Me"/>
</LinearLayout>
    

3. Style & Appearance:

Customize colors, fonts, padding, margins, backgrounds, etc.

<TextView
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:text="Styled Text"
    android:textColor="#FF0000"
    android:textSize="20sp"
    android:padding="10dp"
    android:background="#FFFF00"/>
    

4. Manage Resources:

Define strings, colors, dimensions, and drawables in separate XML files for centralized management.

Example: res/values/strings.xml

<resources>
    <string name="app_name">My App</string>
</resources>
    

5. Dynamic Binding with Code:

Access XML elements in Java/Kotlin to control app behavior.

TextView tv = findViewById(R.id.myTextView);
tv.setText("Hello World!");
    

Java in Android

What is Java:

Java is a high-level, object-oriented programming language. In Android, Java is one of the main languages used to develop apps. It allows developers to write logic, handle events, and control app behavior.

What you can do with Java in Android:

1. Write App Logic:

Java is used to define how the app works behind the scenes, like calculations, data processing, and logic flow.

int a = 10;
int b = 20;
int sum = a + b;
System.out.println("Sum: " + sum);
    

2. Handle User Interaction:

Respond to user actions like clicks, text input, or gestures.

Button btn = findViewById(R.id.myButton);
btn.setOnClickListener(new View.OnClickListener() {
    @Override
    public void onClick(View v) {
        Toast.makeText(getApplicationContext(), "Button clicked!", Toast.LENGTH_SHORT).show();
    }
});
    

3. Connect with XML UI:

Java interacts with XML elements to control UI dynamically.

TextView tv = findViewById(R.id.myTextView);
tv.setText("Hello from Java!");
    

4. Manage Data:

Handle variables, arrays, objects, and database operations.

String name = "Android";
int[] scores = {90, 85, 70};
for(int score : scores) {
    System.out.println(score);
}
    

5. Implement App Features:

Java is used to add features like navigation, network requests, notifications, sensors, etc.

Intent intent = new Intent(MainActivity.this, SecondActivity.class);
startActivity(intent);
    

Firebase in Android

What is Firebase:

Firebase is a platform developed by Google that provides backend services for mobile and web applications. In Android, Firebase helps developers manage databases, authentication, storage, analytics, notifications, and more without managing their own server.

What you can do with Firebase in Android:

1. Realtime Database:

Store and sync data in real-time across all connected devices.

// Writing data
DatabaseReference ref = FirebaseDatabase.getInstance().getReference("users");
ref.child("user1").setValue(new User("John", "Doe"));
    

2. Authentication:

Enable user login and registration with email/password, phone, or social accounts.

FirebaseAuth auth = FirebaseAuth.getInstance();
auth.createUserWithEmailAndPassword(email, password)
    .addOnCompleteListener(task -> {
        if(task.isSuccessful()) {
            // User created
        }
    });
    

3. Firestore Database:

A modern NoSQL cloud database for storing structured data.

FirebaseFirestore db = FirebaseFirestore.getInstance();
Map<String, Object> user = new HashMap<>();
user.put("name", "Alice");
user.put("age", 25);
db.collection("users").document("user1").set(user);
    

4. Cloud Storage:

Store and retrieve files like images, videos, and documents.

StorageReference storageRef = FirebaseStorage.getInstance().getReference();
StorageReference imgRef = storageRef.child("images/photo.jpg");
imgRef.putFile(fileUri);
    

5. Push Notifications (FCM):

Send notifications to app users through Firebase Cloud Messaging.

FirebaseMessaging.getInstance().subscribeToTopic("news");
FirebaseMessaging.getInstance().send(message);
    

6. Analytics:

Track app usage and user behavior.

FirebaseAnalytics analytics = FirebaseAnalytics.getInstance(this);
Bundle bundle = new Bundle();
bundle.putString(FirebaseAnalytics.Param.ITEM_NAME, "App Opened");
analytics.logEvent(FirebaseAnalytics.Event.SELECT_CONTENT, bundle);
    

MySQL in Android

What is MySQL:

MySQL is a popular open-source relational database management system (RDBMS). In Android, MySQL is often used with a backend server (like PHP) to store and manage app data.

What you can do with MySQL in Android:

1. Store Data:

MySQL allows you to store structured data in tables with rows and columns.

CREATE TABLE users (
    id INT AUTO_INCREMENT PRIMARY KEY,
    name VARCHAR(100),
    email VARCHAR(100)
);
    

2. Retrieve Data:

Fetch data from the database to use in your Android app.

SELECT * FROM users;
    

3. Insert Data:

Add new records into the database.

INSERT INTO users (name, email) VALUES ('John Doe', 'john@example.com');
    

4. Update Data:

Modify existing records.

UPDATE users SET email='john.doe@example.com' WHERE id=1;
    

5. Delete Data:

Remove records from the database.

DELETE FROM users WHERE id=1;
    

6. Connect Android to MySQL:

Since Android cannot directly connect to MySQL, you use a server-side script (PHP/Node.js) to interact with the database.

URL url = new URL("https://example.com/api/getUsers.php");
HttpURLConnection conn = (HttpURLConnection) url.openConnection();
InputStream in = conn.getInputStream();
// Read JSON data and display in Android app
    

SQLite in Android

What is SQLite:

SQLite is a lightweight, built-in relational database in Android. It allows apps to store data locally on the device without the need for a server.

What you can do with SQLite in Android:

1. Create Database and Tables:

Define your local database and tables to store structured data.

SQLiteDatabase db = openOrCreateDatabase("MyDatabase", MODE_PRIVATE, null);
db.execSQL("CREATE TABLE IF NOT EXISTS users(id INTEGER PRIMARY KEY, name TEXT, email TEXT);");
    

2. Insert Data:

Add new records into the SQLite database.

db.execSQL("INSERT INTO users(name, email) VALUES('John Doe', 'john@example.com');");
    

3. Retrieve Data:

Fetch data to use in your app.

Cursor cursor = db.rawQuery("SELECT * FROM users", null);
while(cursor.moveToNext()) {
    String name = cursor.getString(1);
    String email = cursor.getString(2);
}
cursor.close();
    

4. Update Data:

Modify existing records.

db.execSQL("UPDATE users SET email='john.doe@example.com' WHERE id=1;");
    

5. Delete Data:

Remove records from the database.

db.execSQL("DELETE FROM users WHERE id=1;");
    

6. Benefits of SQLite:

• Local storage without server requirement.
• Lightweight and fast for small to medium data.
• Easy integration with Android apps.
• Supports SQL queries for data manipulation.

API Integration in Android

What is API Integration:

API (Application Programming Interface) integration allows an Android app to communicate with external services or servers to send and receive data. It is commonly used to fetch data from the web, send data to a backend, or connect with third-party services.

What you can do with API Integration in Android:

1. Fetch Data from Server:

Retrieve information like JSON or XML from a remote server.

URL url = new URL("https://example.com/api/getUsers");
HttpURLConnection conn = (HttpURLConnection) url.openConnection();
InputStream in = conn.getInputStream();
// Parse JSON and display in app
    

2. Send Data to Server:

Send user input or app data to a server using POST or PUT requests.

URL url = new URL("https://example.com/api/addUser");
HttpURLConnection conn = (HttpURLConnection) url.openConnection();
conn.setRequestMethod("POST");
conn.setDoOutput(true);
OutputStream os = conn.getOutputStream();
os.write(postData.getBytes());
os.flush();
os.close();
    

3. Use Third-Party APIs:

Integrate services like Google Maps, Firebase APIs, Payment gateways, or social media APIs.

// Example: Google Maps API
SupportMapFragment mapFragment = (SupportMapFragment) getSupportFragmentManager().findFragmentById(R.id.map);
mapFragment.getMapAsync(this);
    

4. Handle JSON Response:

Parse JSON data received from APIs and display in the app.

JSONObject obj = new JSONObject(responseString);
String name = obj.getString("name");
int age = obj.getInt("age");
    

5. Error Handling:

Manage network errors, timeouts, and invalid responses.

try {
    // API call
} catch (IOException e) {
    e.printStackTrace();
}
    

6. Benefits of API Integration:

• Access external data and services easily.
• Enable dynamic app content.
• Connect to third-party services and tools.
• Maintain app-server communication securely.