Android Development Posts

Hi everyone, in this post, we will discuss Room Database in android java.

Below are all steps covered in this blog

• How to use the Room database
• How to add Room Database in android studio
• Insert,Update,Delete record
• How to pass query in Database

What is a Room?

• The Room strong library provides an abstraction layer over SQLite to allow for more robust database access while harnessing the full power of SQLite.

• Normally Room databases are fast created and have good performance like reading, updating and deleting records. Room Database makes everything easy and fast

• Room Database more detail open this link: https://developer.android.com/training/data-storage/room/

Components of Room Here room have main 3 components

Entity:

• Instead of creating the SQLite table, we will create the Entity. An entity is nothing but a model class annotated with @Entity. The variables of this class are our columns, and the class is our table.

Database:

• It is an abstract class where we define all our entities.

DAO:

• Stands for Data Access Objects. It is an interface that defines all the operations that we need to perform in our database.

Demo App Create

• First, we create a new project in android studio.
• Name of my project "Room DataBase"

Adding Dependencies

• Add needed dependencies for the room database.
• Android studio in this file add dependencies "build.gradle".
• See the below image and add the latest version room database replace here "$room_version" add original version

First, we will create DAO class:

• This DAO class-main work intermediary between the user and database. All performed operations are defined here.
• Below create StudentDao class

@Dao
public interface StudentDao {

@Query("SELECT * FROM Student")
List<Student> getAll();

@Insert
void insert(Student student);

@Update
void updateTask(Student student);

@Delete
void deleteTask(Student student);
}

Nowhere explain all components of StudentDao Class

• Compulsory add class upper "@Dao" keyword
• Three methods create insert, update, delete
• Most important thing here is "@Query"

What is a Query?

• Using query to get database existing record.
• @Query("SELECT * FROM Student") this query gets all student records.
• But the user wants to get only the standard "5" student record and only get how to pass a query?

    @Query("SELECT * FROM STUDENT where std = :std")

    List<Student> dataCheck(String std);

• Here "std" id table field name
• Call this method "data check(String std)" pass a string in "5" and database in getting only 5 stander student record
• So this concept use the query parameter

Second steps create student model class

@Entity(tableName = "student")
public class Student implements Serializable {

@PrimaryKey(autoGenerate  = true)
private int id;

@ColumnInfo(name = "std")
private int std;

@ColumnInfo(name = "name")
private String name;

public int getId() {
    return id;
  }

public void setId(int id) {
    this.id = id;
  }

public int getStd() {
    return std;
  }

public void setStd(int std) {
    this.std = std;
  }

public String getName() {
    return name;
  }

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

• PrimaryKey: auto increment values
• tableName : user wants to set the table name
• ColumnInfo: give the table in columns name

Third steps Create Database class:

@Database(entities = {Student.class}, version = 1)
public abstract class AppDatabase extends     RoomDatabase {
public abstract Student studentDao();
}

• User wants to add multiple tables how can add like that:

@Database(entities = {Student.class,Abc.class,Xyz.class}, version = 1) public abstract class AppDatabase extends RoomDatabase { public abstract Student studentDao(); }

• To create a new model class like Abc.class and Xyz.class etc same method.

Fourth step inserts, update and delete records create separate method:

• But implements upper all method in understanding asynctask
• You, not knowing whats is asynctask first open this link and check it: https://developer.android.com/reference/android/os/AsyncTask
• how we will create a common class method insert,update, delete

 public class InsertUpdateDeletRecord {

    private String DB_NAME = "db_task";

    private Student Student;
    public studentRepository(Context context) {
        Student = Room.databaseBuilder(context, Student.class, DB_NAME).build();
    }

    public void insertTask(String std,String name) {

        insertTask(std, name);
    }

    public void insertTask(String std,String name) {
        Student student = new Student();
        student.setstd(std);
        student.setname(name);

        insertTask(student);
    }

    public void insertTask(final Student student) {
        new AsyncTask<Void, Void, Void>() {
            @Override
            protected Void doInBackground(Void... voids) {
                Student.daoAccess().insertTask(student);
                return null;
            }
        }.execute();
    }

    public void updateTask(final Student student) {
        student.setModifiedAt(AppUtils.getCurrentDateTime());

        new AsyncTask<Void, Void, Void>() {
            @Override
            protected Void doInBackground(Void... voids) {
                Student.daoAccess().updateTask(student);
                return null;
            }
        }.execute();
    }

    public void deleteTask(final int id) {
        final LiveData<student> task = getTask(id);
        if(task != null) {
            new AsyncTask<Void, Void, Void>() {
                @Override
                protected Void doInBackground(Void... voids) {
                    Student.daoAccess().deleteTask(task.getValue());
                    return null;
                }
            }.execute();
        }
    }

    public void deleteTask(final student student) {
        new AsyncTask<Void, Void, Void>() {
            @Override
            protected Void doInBackground(Void... voids) {
                Student.daoAccess().deleteTask(student);
                return null;
            }
        }.execute();
    }

 }

Sample Implementation of basic CRUD operations using ROOM

Insert:

 InsertUpdateDeletRecord 
 insertUpdateDeletRecord = new 
 InsertUpdateDeletRecord(getApplicationContext( ));
 String std = "5";
 String name = Android";
 insertUpdateDeletRecord.insertTask(title, 
 description);

Update:

 InsertUpdateDeletRecord 
 insertUpdateDeletRecord = new 
 InsertUpdateDeletRecord(getApplicationContext( ));
 Student student = 
 insertUpdateDeletRecord.getTask(2);
 student.setName("Java");
 student.setStd("6");
 insertUpdateDeletRecord.updateTask(student);

Update:

 InsertUpdateDeletRecord 
 insertUpdateDeletRecord = new 
 InsertUpdateDeletRecord(getApplicationContext());
 insertUpdateDeletRecord.deleteTask(3);

Dear, Friend in this blog we discussion google ad integration. Many companies work in client base & product base. Product based company in very very important ad integration in the app. Multiple types of AD are available like a Facebook ad, start-up ad, google ad, etc. Today we learning google ad integration.

Type of Google AD:

• Banner AD
• Interstitial Ad
• Rewarded Video Ad
• Native Ad

1.Banner Ad

Banner Ads occupy only a portion of the screen depending on the ad size that is created. It comes in multiple sizes Standard, Medium, Large, Full-Size, Leaderboard, and Smart Banner. Smart banners are very useful when you target multiple device sizes and fit the same ad depending on the screen size.

2.Interstitial Ads

Interstitial ads occupy the full screen of the app. Basically, they will show on a timely basis, between screen transition or when the user is done with a task.

3.Rewarded Video Ad

This ad shows a video-type ad.

4.Native Ad

In this app in full description ad showing.

Create a new project

Create a new project in Android Studio from File ⇒ New Project.

Open build. Gradle and add play services dependency as AdMob requires it.

compile ‘com.google.android.gms:play-services-ads:11.8.0’

build.gradle
dependencies {
    compile fileTree(dir: 'libs', include: ['*.jar'])
    testCompile 'junit:junit:4.12'
    compile 'com.android.support:appcompat-v7:26.1.0'
    compile 'com.android.support:design:26.1.0'

    compile 'ccom.google.android.gms:play-services-ads:11.8.0'
}

Add the App ID and Ad unit IDs to your strings.xml.

    AdMob
    Interstitial
    Welcome to Admob. Click on the below button to launch the Interstitial ad.
    Show Interstitial Ad
    Show Rewarded Video Ad

    ca-app-pub-XXXXXXXX~XXXXXXXXXXX
    ca-app-pub-XXXXXXXX~XXXXXXXXXXX
    ca-app-pub-XXXXXXXX~XXXXXXXXXXX
    ca-app-pub-XXXXXXXX~XXXXXXXXXXX

Create a class named MyApplication.java and extend the class from Application. In this application class, we have to globally initialize the AdMob App Id. Here we use MobileAds.initialize()

MyApplication.java

public class MyApplication extends Application {

    @Override
    public void onCreate() {
        super.onCreate();
         MobileAds.initialize(this, getString(R.string.admob_app_id));
    }
}

Open AndroidManifest.xml and add MyApplication to tag.

<meta-data
    android:name="com.google.android.gms.ads.APPLICATION_ID"
    android:value="ca-app-pub-3940256099942544/6300978111"/>

Basically, it works like a stack where each view is stacked on top of the other.

Create a drawable file for shadow view and assign the name image_shadow and add the below code in this file.

<?xml version="1.0" encoding="utf-8"?>
<shape xmlns:android="http://schemas.android.com/apk/res/android"
    android:shape="rectangle">
    <corners android:radius="10dp" />
    <gradient
    android:angle="270"
    android:centerX="300%"
    android:endColor="#99000000"
    android:startColor="#00000000"
    android:type="linear" />
    <size
    android:width="270dp"
    android:height="60dp" />
    <stroke
    android:width="1dp"
    android:color="#878787" />
</shape>

Now, open the XML file and add the below code into it, and set this drawable file as view background.

<androidx.appcompat.widget.LinearLayoutCompat
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"
xmlns:app="http://schemas.android.com/apk/res-auto"
tools:context=".MainActivity">
<androidx.constraintlayout.widget.ConstraintLayout
    android:layout_width="match_parent"
    android:layout_height="match_parent">
    <androidx.appcompat.widget.AppCompatImageView
        android:id="@+id/imageView"
        android:layout_width="250dp"
        android:layout_height="250dp"
        android:scaleType="centerCrop"
        android:src="@drawable/shopping_image"
        app:layout_constraintTop_toTopOf="parent"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintBottom_toBottomOf="parent"/>
    <View android:id="@+id/view"
        android:layout_width="250dp"
        android:layout_height="250dp"
        android:background="@drawable/image_shadow"
        app:layout_constraintTop_toTopOf="parent"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintBottom_toBottomOf="parent"/>
    <androidx.appcompat.widget.AppCompatTextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_margin="10dp"
        android:textColor="@android:color/white"
        android:text="Write your text here"
        android:textSize="25sp"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintBottom_toBottomOf="@+id/view"/>
</androidx.constraintlayout.widget.ConstraintLayout>
</androidx.appcompat.widget.LinearLayoutCompat>

That's it. You should be ready to go.

We will learn to run the app without connecting a USB cable in this blog. The main purpose of this blog is to let users run apps without any restriction. Sometimes if the cable is connected with the device and if the device cable gets disturbed then the app does not run properly.

Let's see how we can run the app without cable.

Step 1: Click File Menu => Settings

Step 2: Click Plugins

Step 3: Install ADB Wi-Fi Plugin

Notes:

• In the third image, I already installed the plugin in my android studio. But in your case, you may need to install it.
• Then your android studio restarts.

After the restart, your android studio will show the "ADB Wifi" option showing as per the following image

Click ADB Wifi and the below screen will be displayed.

• Click to connect
• Make sure your device and pc are connected to the same wifi. Otherwise, it will not get connected.
• You will need to connect one time when the android studio is opened for the first time.

Snackbars are fairly common in the Android app. Almost every app uses a snack bar to display some information about what's going on in the app. You can consider Snackbar as an alternative or the best version of Toasts in Android.

Step 1: Using a normal Snackbar

To use Snackbar in your app, you just have to have the material design dependency in your app. Add Material design dependency to your build.Gradle app-level.

dependencies {
    implementation "com.google.android.material:$latest_version"
}

And then you can use the snack bar just like toast. For example:

Snackbar.make(view, "Show some message here", Snackbar.LENGTH_SHORT).show()

Step 2: Working with the MainActivity.xml

<?xml version="1.0" encoding="utf-8"?>
<android.support.design.widget.CoordinatorLayout 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:id="@+id/coordinatorLayout"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context="com.example.application.snackbarapp.MainActivity">

    <RelativeLayout
        android:layout_width="match_parent"
        android:layout_height="match_parent">

        <Button
            android:id="@+id/button"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_centerHorizontal="true"
            android:layout_centerVertical="true"
            android:text="show snackbar" />

    </RelativeLayout>

</android.support.design.widget.CoordinatorLayout>

Step 3: Creating a custom layout for a snack bar

Under Layout, the folder creates a layout for the snack bar that must be inflated when creating a snack bar under the mainactivity.java file.

import android.graphics.Color;
import android.support.design.widget.CoordinatorLayout;
import android.support.design.widget.Snackbar;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.TextView;

public class MainActivity extends AppCompatActivity {
    private CoordinatorLayout coordinatorLayout;
    private Button button;

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

        coordinatorLayout = findViewById(R.id.coordinatorLayout);
        button = findViewById(R.id.button);

        button.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                showSnackbar();
            }
        });
    }

    public void showSnackbar() {
        Snackbar snackbar = Snackbar.make(coordinatorLayout, "Marked as Read", Snackbar.LENGTH_INDEFINITE)
                .setAction("UNDO", new View.OnClickListener() {
                    @Override
                    public void onClick(View v) {
                        Snackbar snackbar1 = Snackbar.make(coordinatorLayout, "Undo successful", Snackbar.LENGTH_SHORT);
                        snackbar1.show();
                    }
                })
                .setActionTextColor(Color.RED);

        snackbar.show();
    }
}

While developing apps in Android Studio, developers can create an APK file and share it with other developers or to QA people for testing purposes.

APK can be created with two types:

1. Debug APK
2. Release APK

• Debug APK is very fast in building and Release APK is a little bit slow.

How to create a Release APK File:

• Flowing below all steps
• Open android studio
• Click Build on the toolbar
• Click Generate Signed Bundle/APK.
• Select APK
• Click the Next button
• After clicking the next button, you will see the following dialog.
• Click the "Create new..." button, highlighted in the following image by a red circle if you are creating an APK for the first time. Otherwise, you can choose from existing.
• It will open one another dialog box
• Key store path in select save location .jks file
• Fill in all the information
• Set a valid name for the key alias
• Set 100 as validity years
• Fill Certificate Information
• Click OK
• After you click on it, select "release" from the dialog box
• Select "V1 (Jar Signature)" & "V2 (Full APK Signature)" checkboxes
• Click Finish
• It will start the process of building your APK

How to create a debug .apk file

• Click Build and select Build Bundles(s)/APK(s)
• Select "Build APK(s)" from the dialog box
• It will start the process of building your debug APK file creating

Hello, friend, the shortcut way everyone likes. but remember a shortcut is to improve yourself and save time. It's a very good way. so in this blog learning the android studio shortcut key.use all short cut key and save time and performance improve

Search Keys:

• Shift+Shift — Search Everywhere
• Ctrl+F — Find Text within a Single File
• Ctrl+Shift+F-Find Text in All Files
• Ctrl+R — Replace Selected Text in a Single File
• Ctrl+Shift+R — Replace Selected Text in all Files (Be Careful while Using This)
• Ctrl+Shift+A —Search for IDE Commands

Navigation Keys:

• Ctrl+N — Navigate to Class
• Ctrl+Shift+N — Navigate to a File
• Ctrl+B — Jump to Declarations
• Alt+ ↑ — Jump to the Previous Method
• Alt+↓ — Jump to Next Method
• Ctrl+G — Jump to Line
• Ctrl+E — Recent Files
• Ctrl+Shift+Backspace — Jump to Last Edited Location
• Ctrl+B — Find Declarations
• Ctrl+Left Mouse(or)Ctrl+Alt+F7— Show Usage
• Alt + F7 / Ctrl + F7 — Find usages /Find usages in file
• Ctrl+Shift+B — Find Implementations
• F3 — Find Next
• Shift+F3 — Find Previous

BookMark Keys:

• F11 — Toggle bookmark
• Ctrl+F11 — Toggle bookmark with the mnemonic(0–9 or A-Z)
• Ctrl +(0–9) — Go to numbered bookmark
• Shift+F11 — Show all Bookmarks
• Ctrl + Shift + F7 — Highlight usages in file

Selection Keys:

• Ctrl + W — Extend selection (selects a word->line->method->Class )
• Ctrl +Shift+ W — Decrease Selection
• Alt + J — Select next occurrence
• Ctrl + Alt + Shift + J — Select all occurrences
• Alt + Shift + J — Unselect occurrence
• Ctrl+Shift+V — Paste from recent buffers (from a History of Copied Contents)

Editing Keys:

• Ctrl+F6 — Refactor Code
• Ctrl+D — Duplicate a Line/Selected part
• Ctrl+Y — Delete a Line/Selected part
• Ctrl+Q — Quick Documentation
• Ctrl + Space — Code completion
• Ctrl+Shift+Space — Smart code completion (by expected type removes unrelated suggestions)
• Alt+Insert — Generate Code
• Ctrl+J — Insert Live template
• Ctrl + O — Override methods
• Ctrl + I — Implement methods
• Ctrl + Alt + T — Surround with…
• Ctrl + / — Comment / uncomment with line comment
• Ctrl + Shift + / — Comment / uncomment with block comment
• Ctrl+Alt+L — Reformat code

Run:

• Ctrl + F9 — Compile and Run Make a project
• Ctrl + Shift + F9 — Compile selected file, package or module
• Shift + F10 — Run
• Shift + F9 — Debug
• Ctrl + Shift + F10 — Run context configuration from editor

Debugging:

• F8 / F7 — Step over / into
• Shift + F7 / Shift + F8 — Smart step into/Step out
• Alt + F9 — Run to cursor
• Alt + F8 — Evaluate expression
• F9 — Resume program
• Ctrl + F8 — Toggle breakpoint
• Ctrl + Shift + F8 — View breakpoints

What is a SplashScreen?

A splash screen is a screen that appears when you open an app on your mobile device. So, we can say that it is the first impression for the user. It is commonly used to show an application logo or an image associated with an application.

Implementation

So instead of using a layout file, we'll refer to the splash screen as the background of the activity theme. first, create an XML drawable splash_background.xml inside the res/drawable folder in

<?xml version="1.0" encoding="utf-8"?> 

   <layer-list xmlns:android="http://schemas.android.com/apk/res/android">
   <item android:drawable="@color/white" />
   <item android:drawable="@drawable/ic_icon_vector" android:gravity="center" />

</layer-list>

next step, set splash_groundground.xml as the background for your splash activity in the theme. Add a new splash to your splash activity.

<!-- Splash Screen theme. -->
<style name="SplashTheme" parent="Theme.AppCompat.NoActionBar">
<item name="android:windowBackground">@drawable/splash_background></item>
</style>

Add your theme to AndroidManifest.xml as your splash activity theme.

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

    <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/Theme">

        <activity
            android:name=".SplashActivity"
            android:theme="@style/SplashTheme">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />
                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
    </application>

</manifest></pre><div>
}

Create a blank activity for SplashActivity.java without XML. This class will only redirect to MainActivity.java.

public class SplashActivity extends AppCompatActivity {
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        startActivity(new Intent(SplashActivity.this, MainActivity.class));
        finish();
    }
}