Android Open Source - hts-cycle Data Base Helper

From Project

Back to project page hts-cycle.


The source code is released under:

GNU General Public License

If you think the Android project hts-cycle listed in this page is inappropriate, such as containing malicious code/tools or violating the copyright, please email info at java2s dot com, thanks.

Java Source Code

package it.uniroma2.wifionoff;
/*  w w  w .  j  a  v  a  2  s .  c o  m*/

import android.content.Context;
import android.database.SQLException;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteException;
import android.database.sqlite.SQLiteOpenHelper;

public class DataBaseHelper extends SQLiteOpenHelper{
//The Android's default system path of your application database.
//private static String lol=Environment.getDataDirectory().toString();
private static String DB_PATH = "/data/data/it.uniroma2.wifionoff/databases/";

private static String DB_NAME = "Db.sqlite";
private SQLiteDatabase myDataBase;
private final Context myContext;
  * Constructor
  * Takes and keeps a reference of the passed context in order to access to the application assets and resources.
  * @param context
public DataBaseHelper(Context context) {
super(context, DB_NAME, null, 1);
this.myContext = context;

  * Creates a empty database on the system and rewrites it with your own database.
  * */
public void createDataBase() throws IOException{
boolean dbExist = checkDataBase();
//do nothing - database already exist
//By calling this method and empty database will be created into the default system path
//of your application so we are gonna be able to overwrite that database with our database.
try {
} catch (IOException e) {
throw new Error("Error copying database");
  * Check if the database already exist to avoid re-copying the file each time you open the application.
  * @return true if it exists, false if it doesn't
private boolean checkDataBase(){
SQLiteDatabase checkDB = null;
String myPath = DB_PATH + DB_NAME;
checkDB = SQLiteDatabase.openDatabase(myPath, null, SQLiteDatabase.OPEN_READONLY);
}catch(SQLiteException e){
//database does't exist yet.
if(checkDB != null){
return checkDB != null ? true : false;
  * Copies your database from your local assets-folder to the just created empty database in the
  * system folder, from where it can be accessed and handled.
  * This is done by transfering bytestream.
  * */
private void copyDataBase() throws IOException{
//Open your local db as the input stream
InputStream myInput = myContext.getAssets().open(DB_NAME);
// Path to the just created empty db
String outFileName = DB_PATH + DB_NAME;
//Open the empty db as the output stream
OutputStream myOutput = new FileOutputStream(outFileName);
//transfer bytes from the inputfile to the outputfile
byte[] buffer = new byte[1024];
int length;
while ((length =>0){
myOutput.write(buffer, 0, length);
//Close the streams
public void openDataBase() throws SQLException{
//Open the database
String myPath = DB_PATH + DB_NAME;
myDataBase = SQLiteDatabase.openDatabase(myPath, null, SQLiteDatabase.OPEN_READONLY);
public synchronized void close() {
if(myDataBase != null)

public void onCreate(SQLiteDatabase db) {


public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {

// Add your public helper methods to access and get content from the database.
// You could return cursors by doing "return myDataBase.query(....)" so it'd be easy
// to you to create adapters for your views.

Java Source Code List