greenDao_preshipped_database_OpenHelper.java

package my;

import android.content.Context;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteDatabase.CursorFactory;
import android.database.sqlite.SQLiteException;
import android.util.Log;

import my.DaoMaster;

import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;

import static android.database.sqlite.SQLiteDatabase.OPEN_READONLY;

public class DatabaseOpenHelper extends DaoMaster.OpenHelper {

    private static final String LOG_TAG = DatabaseOpenHelper.class.getSimpleName();

    private static final String ASSETS_DATABASE_FILE_NAME = "downloadedDb";

    private static final String INTERNAL_DATABASE_NAME = "downloadedDb";

    private String internalDatabaseAbsolutePath;

    private Context context;

    public DatabaseOpenHelper(Context context, String name, CursorFactory factory) {
        super(context, name, factory);
        this.context = context;
        internalDatabaseAbsolutePath = context.getDatabasePath(INTERNAL_DATABASE_NAME).getAbsolutePath();
        try {
            createDataBase();
        } catch (Exception ioe) {
            throw new Error("Unable to create database");
        }
    }

    public void createDataBase() {
        if (!databaseExists()) {
            SQLiteDatabase sqliteDatabase = this.getReadableDatabase();
            sqliteDatabase.close();
            copyDataBase();
        }
    }

    private boolean databaseExists() {
        SQLiteDatabase db = null;
        try {
            db = SQLiteDatabase.openDatabase(internalDatabaseAbsolutePath, null, OPEN_READONLY);
        } catch (SQLiteException e) {
            Log.w(LOG_TAG, "Error when trying to open database", e);
        } finally {
            if (db != null) {
                db.close();
            }
        }
        return db != null;
    }

    public void copyDataBase() {
        int length;
        byte[] buffer = new byte[1024];
        try {
            InputStream assetsFile = this.context.getAssets().open(ASSETS_DATABASE_FILE_NAME);
            OutputStream outputStream = new FileOutputStream(internalDatabaseAbsolutePath);
            while ((length = assetsFile.read(buffer)) > 0) {
                outputStream.write(buffer, 0, length);
                outputStream.flush();
            }
            assetsFile.close();
            outputStream.close();
        } catch (IOException e) {
            Log.w(LOG_TAG, "Error when trying to copy database", e);
        }
    }

    @Override
    public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
        Log.i(LOG_TAG, String.format("Upgrading schema from version %d to %d by dropping all tables",
                oldVersion, newVersion));
        DaoMaster.dropAllTables(db, true);
        createDataBase();
    }
}