Télécharger la base de données SQLite à partir d'Internet et de les charger dans l'application Android

Ayant été demandé quelle est la solution que j'ai fini avec, voici le code que j'ai utilisé (à peu près). Il peut ne pas être complète, et de plus, il n'est pas élégant ou propre, soit. Mais peut-être cela peut vous aider.

MyActivity.java

public class MyActivity extends Activity {
private static final String SD_CARD_FOLDER = "MyApp";
private static final String DB_DOWNLOAD_PATH = "http://www.example.org/downloads/dictionary.sqlite";
private Database mDB = null;
private DatabaseDownloadTask mDatabaseDownloadTask = null;
private DatabaseOpenTask mDatabaseOpenTask = null;
private class DatabaseDownloadTask extends AsyncTask<Context, Integer, Boolean> {
@Override
protected void onPreExecute() {
mProgressDialog = new ProgressDialog(MyActivity.this);
mProgressDialog.setTitle(getString(R.string.please_wait));
mProgressDialog.setMessage(getString(R.string.downloading_database));
mProgressDialog.setIndeterminate(false);
mProgressDialog.setMax(100);
mProgressDialog.setProgressStyle(ProgressDialog.STYLE_HORIZONTAL);
mProgressDialog.setCancelable(false);
mProgressDialog.show();
getWindow().addFlags(WindowManager.LayoutParams.FLAG_KEEP_SCREEN_ON);
}
@Override
protected Boolean doInBackground(Context... params) {
try {
File dbDownloadPath = new File(Database.getDatabaseFolder());
if (!dbDownloadPath.exists()) {
dbDownloadPath.mkdirs();
}
HttpParams httpParameters = new BasicHttpParams();
HttpConnectionParams.setConnectionTimeout(httpParameters, 5000);
HttpConnectionParams.setSoTimeout(httpParameters, 5000);
DefaultHttpClient client = new DefaultHttpClient(httpParameters);
HttpGet httpGet = new HttpGet(DB_DOWNLOAD_PATH);
InputStream content = null;
try {
HttpResponse execute = client.execute(httpGet);
if (execute.getStatusLine().getStatusCode() != 200) { return null; }
content = execute.getEntity().getContent();
long downloadSize = execute.getEntity().getContentLength();
FileOutputStream fos = new FileOutputStream(Database.getDatabaseFolder()+Database.DATABASE_NAME+".sqlite");
byte[] buffer = new byte[256];
int read;
long downloadedAlready = 0;
while ((read = content.read(buffer)) != -1) {
fos.write(buffer, 0, read);
downloadedAlready += read;
publishProgress((int) (downloadedAlready*100/downloadSize));
}
fos.flush();
fos.close();
content.close();
return true;
}
catch (Exception e) {
if (content != null) {
try {
content.close();
}
catch (IOException e1) {}
}
return false;
}
}
catch (Exception e) {
return false;
}
}
protected void onProgressUpdate(Integer... values) {
if (mProgressDialog != null) {
if (mProgressDialog.isShowing()) {
mProgressDialog.setProgress(values[0]);
}
}
}
@Override
protected void onPostExecute(Boolean result) {
if (mProgressDialog != null) {
mProgressDialog.dismiss();
mProgressDialog = null;
}
if (result.equals(Boolean.TRUE)) {
Toast.makeText(MyActivity.this, getString(R.string.database_download_success), Toast.LENGTH_LONG).show();
mDatabaseOpenTask = new DatabaseOpenTask();
mDatabaseOpenTask.execute(new Context[] { MyActivity.this });
}
else {
Toast.makeText(getApplicationContext(), getString(R.string.database_download_fail), Toast.LENGTH_LONG).show();
finish();
}
}
}
private class DatabaseOpenTask extends AsyncTask<Context, Void, Database> {
@Override
protected Database doInBackground(Context ... ctx) {
try {
String externalBaseDir = Environment.getExternalStorageDirectory().getAbsolutePath();
// DELETE OLD DATABASE ANFANG
File oldFolder = new File(Environment.getExternalStorageDirectory().getAbsolutePath()+"/"+SD_CARD_FOLDER);
File oldFile = new File(oldFolder, "dictionary.sqlite");
if (oldFile.exists()) {
oldFile.delete();
}
if (oldFolder.exists()) {
oldFolder.delete();
}
// DELETE OLD DATABASE ENDE
File newDB = new File(Database.getDatabaseFolder()+"dictionary.sqlite");
if (newDB.exists()) {
return new Database(ctx[0]);
}
else {
return null;
}
}
catch (Exception e) {
return null;
}
}
@Override
protected void onPreExecute() {
mProgressDialog = ProgressDialog.show(MainActivity.this, getString(R.string.please_wait), "Loading the database! This may take some time ...", true);
}
@Override
protected void onPostExecute(Database newDB) {
if (mProgressDialog != null) {
mProgressDialog.dismiss();
mProgressDialog = null;
}
if (newDB == null) {
mDB = null;
AlertDialog.Builder downloadDatabase = new AlertDialog.Builder(MyActivity.this);
downloadDatabase.setTitle(getString(R.string.downloadDatabase));
downloadDatabase.setCancelable(false);
downloadDatabase.setMessage(getString(R.string.wantToDownloadDatabaseNow));
downloadDatabase.setPositiveButton(getString(R.string.download), new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int which) {
dialog.dismiss();
mDatabaseDownloadTask = new DatabaseDownloadTask();
mDatabaseDownloadTask.execute();
}
});
downloadDatabase.setNegativeButton(getString(R.string.cancel), new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int which) {
dialog.dismiss();
finish();
}
});
downloadDatabase.show();
}
else {
mDB = newDB;
}
}
}
@Override
public void onDestroy() {
super.onDestroy();
if (mDatabaseDownloadTask != null) {
if (mDatabaseDownloadTask.getStatus() != AsyncTask.Status.FINISHED) {
mDatabaseDownloadTask.cancel(true);
}
}
if (mDatabaseOpenTask != null) {
if (mDatabaseOpenTask.getStatus() != AsyncTask.Status.FINISHED) {
mDatabaseOpenTask.cancel(true);
}
}
if (mProgressDialog != null) {
mProgressDialog.dismiss();
mProgressDialog = null;
}
if (mDB != null) {
mDB.close();
mDB = null;
}
}
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
if (!Environment.getExternalStorageState().equals(Environment.MEDIA_MOUNTED)) {
Toast.makeText(getApplicationContext(), getString(R.string.sd_card_not_found), Toast.LENGTH_LONG).show();
finish();
}
mDatabaseOpenTask = new DatabaseOpenTask();
mDatabaseOpenTask.execute(new Context[] { this });
}
}

Database.java

public de la classe de Base de données s'étend SQLiteOpenHelper {

private static final String DATABASE_NAME = "dictionary";
private String DATABASE_PATH = null;
private static final int DATABASE_VERSION = 1;
private static final String PACKAGE_NAME = "com.my.package";
private SQLiteDatabase db;
public Database(Context context) {
super(context, DATABASE_NAME, null, DATABASE_VERSION);
DATABASE_PATH = getDatabaseFolder()+DATABASE_NAME+".sqlite";
db = getWritableDatabase();
}
public static String getDatabaseFolder() {
return Environment.getExternalStorageDirectory().getAbsolutePath()+"/Android/data/"+PACKAGE_NAME+"/databases/";
}
@Override
public synchronized SQLiteDatabase getWritableDatabase() {
try {
if (db != null) {
if (db.isOpen()) {
return db;
}
}
return SQLiteDatabase.openDatabase(DATABASE_PATH, null, SQLiteDatabase.OPEN_READWRITE | SQLiteDatabase.NO_LOCALIZED_COLLATORS);
}
catch (Exception e) {
return null;
}
}
@Override
public synchronized void close() {
if (db != null) {
db.close();
db = null;
}
super.close();
}
@Override
public void onCreate(SQLiteDatabase db) { }
@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) { }

}