Question

我的Android应用程序需要使用现有的SQLiteDatabase文件（xxx.db），在eclipse项目中，我应该在哪个项目文件夹中放置这个数据库文件？如何在我的代码中获取数据库？

Answer 1

只需将您的xxx.db文件放入资产文件夹即可。

public class DatabaseHelper extends SQLiteOpenHelper {

    private static String TAG = "DataBaseHelper"; // Tag just for the LogCat window
    // destination path (location) of our database on device
    private static String DB_PATH = "";
    private static String DB_NAME = "xxx.db";// Database name
    private SQLiteDatabase mDataBase;
    private final Context mContext;

    public DatabaseHelper(Context context) {
        super(context, DB_NAME, null, 1);// 1? its Database Version
        if (android.os.Build.VERSION.SDK_INT >= 4.2) {
            DB_PATH = context.getApplicationInfo().dataDir + "/databases/";
        } else {
            DB_PATH = context.getFilesDir().getPath() + context.getPackageName() + "/databases/";
        }
        this.mContext = context;
    }

    public void createDataBase() throws IOException {
        // If database not exists copy it from the assets
        boolean mDataBaseExist = checkDataBase();
        if (!mDataBaseExist) {
            this.getReadableDatabase();
            this.close();
            try {
                // Copy the database from assests
                copyDataBase();
                Log.e(TAG, "createDatabase database created");
            } catch (IOException mIOException) {
                throw new Error("ErrorCopyingDataBase");
            }
        }
    }

    // Check that the database exists here: /data/data/your package/databases/Da
    // Name
    private boolean checkDataBase() {
        File dbFile = new File(DB_PATH + DB_NAME);
        return dbFile.exists();
    }

    // Copy the database from assets
    private void copyDataBase() throws IOException {
        InputStream mInput = mContext.getAssets().open(DB_NAME);
        String outFileName = DB_PATH + DB_NAME;
        OutputStream mOutput = new FileOutputStream(outFileName);
        byte[] mBuffer = new byte[1024];
        int mLength;
        while ((mLength = mInput.read(mBuffer)) > 0) {
            mOutput.write(mBuffer, 0, mLength);
        }
        mOutput.flush();
        mOutput.close();
        mInput.close();
    }

    // Open the database, so we can query it
    public boolean openDataBase() throws SQLException {
        String mPath = DB_PATH + DB_NAME;
        mDataBase = SQLiteDatabase.openDatabase(mPath, null,
                SQLiteDatabase.CREATE_IF_NECESSARY);
        return mDataBase != null;
    }

    @Override
    public synchronized void close() {
        if (mDataBase != null)
            mDataBase.close();
        super.close();
    }

    @Override
    public void onCreate(SQLiteDatabase db) {
        // TODO Auto-generated method stub

    }

    @Override
    public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
        // TODO Auto-generated method stub

    }
}

如何在Android应用程序中获取自己的SQLiteDatabase文件？

1 个答案: