Import Database with Images in Android

The article Import and Use External Database in Android explains, how to distribute an Android application along with the data stored in SQLite database. This tutorial explains, how to store images in such a database and pack it in your application. In other words, we are going to create a database with images from our desktop computer and import it into an Android application.

Step 1:

Create a database "images.db" using your favorite SQLite database application (I use Sqliteman because it allows inserting images into the database. You can use any software or script to insert the images into the database). Create a table 'places' with a two columns 'name' and 'image'. Here the data type of 'name' is TEXT and data type of 'image' is BLOB. Insert the name and image of  some places into the database. In this example, I have inserted the names of the seven wonders of the world along with a compressed (Using TinyPng) picture of them. To download the images used in this project, Click Here.

Step 2:

Create a new application “Image Database Demo” with a package name “com.javahelps.imagedatabasedemo”. and insert the SQLiteAssetHelper library and the compressed images.db into the project as provided in Import and Use External Database in Android tutorial.

Step 3:

Create a new class 'DatabaseOpenHelper'

package com.javahelps.imagedatabasedemo;

import android.content.Context;

import com.readystatesoftware.sqliteasset.SQLiteAssetHelper;

public class DatabaseOpenHelper extends SQLiteAssetHelper {
    private static final String DATABASE_NAME = "images.db";
    private static final int DATABASE_VERSION = 1;

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

Step 4:

Create a new class DatabaseAccess and enter the code as shown below.

package com.javahelps.imagedatabasedemo;

import android.content.Context;
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteOpenHelper;

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

/**
 * Created by gobinath on 4/7/16.
 */
public class DatabaseAccess {
    private SQLiteOpenHelper openHelper;
    private SQLiteDatabase database;
    private static DatabaseAccess instance;

    /**
     * Private constructor to avoid object creation from outside classes.
     *
     * @param context
     */
    private DatabaseAccess(Context context) {
        this.openHelper = new DatabaseOpenHelper(context);
    }

    /**
     * Return a singleton instance of DatabaseAccess.
     *
     * @param context the Context
     * @return the instance of DabaseAccess
     */
    public static DatabaseAccess getInstance(Context context) {
        if (instance == null) {
            instance = new DatabaseAccess(context);
        }
        return instance;
    }

    /**
     * Open the database connection.
     */
    public void open() {
        this.database = openHelper.getWritableDatabase();
    }

    /**
     * Close the database connection.
     */
    public void close() {
        if (database != null) {
            this.database.close();
        }
    }

    /**
     * Read all quotes from the database.
     *
     * @return a List of quotes
     */
    public List<String> getNames() {
        List<String> list = new ArrayList<>();
        Cursor cursor = database.rawQuery("SELECT name FROM places", null);
        cursor.moveToFirst();
        while (!cursor.isAfterLast()) {
            list.add(cursor.getString(0));
            cursor.moveToNext();
        }
        cursor.close();
        return list;
    }

    /**
     * Read the BLOB data as byte[]
     *
     * @param name name of the place
     * @return image as byte[]
     */
    public byte[] getImage(String name) {
        byte[] data = null;
        Cursor cursor = database.rawQuery("SELECT image FROM places WHERE name = ?", new String[]{name});
        cursor.moveToFirst();
        while (!cursor.isAfterLast()) {
            data = cursor.getBlob(0);
            break;  // Assumption: name is unique
        }
        cursor.close();
        return data;
    }
}

The getImage method in this class, retrieve the BLOB image as an array of byte.

Step 5:

Create a Spinner and ImageView in the activity_main.xml as shown below.

<?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:paddingBottom="@dimen/activity_vertical_margin"
    android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    tools:context="com.javahelps.imagedatabasedemo.MainActivity">

    <Spinner
        android:id="@+id/cmbName"
        android:layout_width="match_parent"
        android:layout_height="wrap_content" />

    <ImageView
        android:id="@+id/imgPlace"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:layout_below="@id/cmbName"
        android:layout_centerHorizontal="true"
        android:layout_centerVertical="true" />
</RelativeLayout>

Step 6:

Find the View objects of Spinner and ImageView in the onCreate method of MainActivity and pass the names of the places to the Spinner using an adapter.

package com.javahelps.imagedatabasedemo;

import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.view.View;
import android.widget.AdapterView;
import android.widget.ArrayAdapter;
import android.widget.ImageView;
import android.widget.Spinner;

import java.util.List;

public class MainActivity extends AppCompatActivity {
    private Spinner cmbName;
    private ImageView imgPlace;

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

        // Initialize the UI components
        this.cmbName = (Spinner) findViewById(R.id.cmbName);
        this.imgPlace = (ImageView) findViewById(R.id.imgPlace);

        // Define final variables since they have to be accessed from inner class
        final DatabaseAccess databaseAccess = DatabaseAccess.getInstance(this);

        // Open the database
        databaseAccess.open();

        // Read all the names
        final List<String> names = databaseAccess.getNames();

        // Close the database
        databaseAccess.close();

        // Create adapter and set to the Spinner
        ArrayAdapter<String> adapter = new ArrayAdapter<String>(this, android.R.layout.simple_spinner_item, names);
        adapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
        this.cmbName.setAdapter(adapter);
    }
}

Step 7:

Set OnItemSelectedListener to Spinner and retrieve the image of the selected place from the database and convert it to Bitmap using toBitmap method as shown below.

package com.javahelps.imagedatabasedemo;

import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.view.View;
import android.widget.AdapterView;
import android.widget.ArrayAdapter;
import android.widget.ImageView;
import android.widget.Spinner;

import java.util.List;

public class MainActivity extends AppCompatActivity {
    private Spinner cmbName;
    private ImageView imgPlace;

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

        // Initialize the UI components
        this.cmbName = (Spinner) findViewById(R.id.cmbName);
        this.imgPlace = (ImageView) findViewById(R.id.imgPlace);

        // Define final variables since they have to be accessed from inner class
        final DatabaseAccess databaseAccess = DatabaseAccess.getInstance(this);

        // Open the database
        databaseAccess.open();

        // Read all the names
        final List<String> names = databaseAccess.getNames();

        // Close the database
        databaseAccess.close();

        // Create adapter and set to the Spinner
        ArrayAdapter<String> adapter = new ArrayAdapter<String>(this, android.R.layout.simple_spinner_item, names);
        adapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
        this.cmbName.setAdapter(adapter);

        this.cmbName.setOnItemSelectedListener(new AdapterView.OnItemSelectedListener() {
            @Override
            public void onItemSelected(AdapterView<?> parent, View view, int position, long id) {
                // Get the selected name
                String name = names.get(position);

                // Open the database
                databaseAccess.open();

                // Retrieve the selected image as byte[]
                byte[] data = databaseAccess.getImage(name);
                // Convert to Bitmap
                Bitmap image = toBitmap(data);
                // Set to the imgPlace
                imgPlace.setImageBitmap(image);

                // Close the database
                databaseAccess.close();
            }

            @Override
            public void onNothingSelected(AdapterView<?> parent) {
                // Do nothing
            }
        });
    }

    /**
     * Convert byte[] to Bitmap
     *
     * @param image
     * @return
     */
    public static Bitmap toBitmap(byte[] image) {
        return BitmapFactory.decodeByteArray(image, 0, image.length);
    }
}

Step 8:

Save all the changes and run the application.

Find the project at Git Hub.

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