-class MobileLedgerDatabase extends SQLiteOpenHelper implements AutoCloseable {
- private static final String DB_NAME = "MoLe.db";
- private static final int LATEST_REVISION = 22;
- private static final String CREATE_DB_SQL = "create_db";
-
- private final Application mContext;
-
- public MobileLedgerDatabase(Application context) {
- super(context, DB_NAME, null, LATEST_REVISION);
- debug("db", "creating helper instance");
- mContext = context;
- super.setWriteAheadLoggingEnabled(true);
- }
-
- @Override
- public void onCreate(SQLiteDatabase db) {
- debug("db", "onCreate called");
- applyRevisionFile(db, CREATE_DB_SQL);
- }
-
- @Override
- public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
- debug("db", "onUpgrade called");
- for (int i = oldVersion + 1; i <= newVersion; i++) applyRevision(db, i);
- }
-
- private void applyRevision(SQLiteDatabase db, int rev_no) {
- String rev_file = String.format(Locale.US, "sql_%d", rev_no);
-
- applyRevisionFile(db, rev_file);
- }
- private void applyRevisionFile(SQLiteDatabase db, String rev_file) {
- final Resources rm = mContext.getResources();
- int res_id = rm.getIdentifier(rev_file, "raw", mContext.getPackageName());
- if (res_id == 0)
- throw new SQLException(String.format(Locale.US, "No resource for %s", rev_file));
- db.beginTransaction();
- try (InputStream res = rm.openRawResource(res_id)) {
- debug("db", "Applying " + rev_file);
- InputStreamReader isr = new InputStreamReader(res);
- BufferedReader reader = new BufferedReader(isr);
-
- String line;
- int line_no = 1;
- while ((line = reader.readLine()) != null) {
- if (line.startsWith("--")) {
- line_no++;
- continue;
- }
- if (line.isEmpty()) {
- line_no++;
- continue;
- }
- try {
- db.execSQL(line);
- }
- catch (Exception e) {
- throw new RuntimeException(
- String.format("Error applying %s, line %d", rev_file, line_no), e);
- }
- line_no++;
- }
-
- db.setTransactionSuccessful();
- }
- catch (IOException e) {
- Log.e("db", String.format("Error opening raw resource for %s", rev_file));
- e.printStackTrace();
- }
- finally {
- db.endTransaction();
- }
- }
-}