I am a beginner in the android world and so I am learning to import data from an existing database created using DB browser. Below I am adding the link from which I am learning to import data from existing database file. How to import and use external database in android studio ?
NOTE: I have correctly placed the .db file in the assets folder.
I am sharing my main.java code below:
package com.javahelps.externaldatabasedemo;
import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.widget.ArrayAdapter;
import android.widget.ListView;
import java.util.List;
public class MainActivity extends AppCompatActivity {
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
ListView listView = findViewById(R.id.listView);
DatabaseAccess databaseAccess = DatabaseAccess.getInstance(this);
databaseAccess.open();
List<String> quotes = databaseAccess.getQuotes();
databaseAccess.close();
ArrayAdapter<String> adapter = new ArrayAdapter<String>(this,
android.R.layout.simple_list_item_1, quotes);
listView.setAdapter(adapter);
}
}
My activity_main.xml file code is :
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout 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:paddingStart="5dp"
android:paddingEnd="5dp"
android:paddingTop="5dp"
android:paddingBottom="5dp"
tools:context=".MainActivity"
android:orientation="vertical">
<ListView
android:id="@+id/listView"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_gravity="center" />
</LinearLayout>
My DatabaseOpenHelper.java class code is as follows:
package com.javahelps.externaldatabasedemo;
import android.content.Context;
import com.readystatesoftware.sqliteasset.SQLiteAssetHelper;
public class DatabaseOpenHelper extends SQLiteAssetHelper {
private static final String DATABASE_NAME = "quotes.db";
private static final int DATABASE_VERSION = 1;
public DatabaseOpenHelper(Context context) {
super(context, DATABASE_NAME, null, DATABASE_VERSION);
}
}
And lastly my DatabaseAccess.java class is :
package com.javahelps.externaldatabasedemo;
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;
public class DatabaseAccess {
private SQLiteOpenHelper openHelper;
private SQLiteDatabase database;
private static DatabaseAccess instance;
private DatabaseAccess(Context context) {
this.openHelper = new DatabaseOpenHelper(context);
}
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> getQuotes() {
List<String> list = new ArrayList<>();
Cursor cursor = database.rawQuery("SELECT quote FROM quotes", null);
cursor.moveToFirst();
while (!cursor.isAfterLast()) {
list.add(cursor.getString(0));
cursor.moveToNext();
}
cursor.close();
return list;
}
}
How can I resolve this problem from the above code?
