SQLiteManager:打开文件时出错吗？

Question

我在SQLite文件夹中有一个assets数据库，然后在app数据文件夹中复制它。

然后，我把它复制到我的电脑上看数据，但得到以下的错误。

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这是我的DB.java：

public class DB extends SQLiteOpenHelper {
    public static final String DIR_SDCARD = Environment
            .getExternalStorageDirectory().getAbsolutePath();
    public static final String DIR_DATABASE = DIR_SDCARD + "/Android/data/";
    private static String DB_NAME = "Rulling_DB.sqlite";
    private final Context myContext;
    public static String PACKAGE_NAME;
    public boolean flag = false;

    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 = DIR_DATABASE + PACKAGE_NAME + "/Rulling/" + 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;
        try {
            while ((length = myInput.read(buffer)) > 0) {
                myOutput.write(buffer, 0, length);
            }
        } catch (IOException e) {
            Log.e("Copy", e.toString());
        }
        // Close the streams
        myOutput.flush();
        myOutput.close();
        myInput.close();

    }

    private boolean checkDataBase() {
        SQLiteDatabase checkDB = null;

        try {

            checkDB = SQLiteDatabase.openDatabase(DIR_DATABASE + PACKAGE_NAME
                    + "/Rulling/" + DB_NAME, null, 0);

        } catch (SQLiteException e) {
            Log.e("asdf", "checkDataBase-->" + e.toString());
        }
        if (checkDB != null) {
            checkDB.close();
        }
        return checkDB != null ? true : false;
    }

    @Override
    public synchronized SQLiteDatabase getReadableDatabase() {
        return super.getReadableDatabase();
    }

    public DB(Context context) {
        super(context, DB_NAME, null, 1);
        this.myContext = context;
    }

    public void CreateandOpenDataBase() throws IOException {
        boolean dbExist = false;
        try {
            dbExist = checkDataBase();
        } catch (Exception e) {
            Log.i("ERROR", "ERROR in DB Class");
        }
        if (dbExist) {
        } else {
            try {
                copyDataBase();
            } catch (IOException e) {
                throw new Error("Error copying database --> " + e.toString());
            }
        }
    }

    public SQLiteDatabase openDataBase() throws SQLException {
        return SQLiteDatabase.openOrCreateDatabase(DIR_DATABASE + PACKAGE_NAME
                + "/Rulling/" + DB_NAME, null);
    }

    public boolean CreateFile() {
        if (flag == false) {
            File file = new File(DIR_DATABASE);
            file.mkdirs();
            return true;
        } else {
            return true;
        }
    }

    public void GetPackageName(String res) {
        PACKAGE_NAME = res;
    }

    @Override
    public void onCreate(SQLiteDatabase db) {

    }

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

    }
}

这是我的save.java：

public class Save_GetResponse{

    public static final String DIR_SDCARD = Environment.getExternalStorageDirectory().getAbsolutePath();
    public static final String DIR_DATABASE = DIR_SDCARD +"/Android/data/";

    public SQLiteDatabase sql;
    public static String PACKAGE_NAME;

    public long InsertData(GetReponse_Structure GRS,Context context){
        DB db = new DB(context);
        PACKAGE_NAME = context.getApplicationContext().getPackageName();
        File file= new File(DIR_DATABASE + PACKAGE_NAME + "/Rulling");
        file.mkdirs();
        db.GetPackageName(PACKAGE_NAME);
        db.CreateFile();
        try {
            db.CreateandOpenDataBase();
        } catch (IOException e) {
            e.printStackTrace();
        }
        sql = db.openDataBase();


        ContentValues values = new ContentValues();
        values.put("ID", GRS._Id );
        values.put("Title",GRS._Title);
        values.put("MetaDataID", GRS._MetaDataID);
        values.put("Comment", GRS._Comment);
        values.put("Tafsir", GRS._Tafsir);
        values.put("CategoryID", GRS._CategoryID);
        values.put("ParentID", GRS._ParentID);
        values.put("LanguageID", GRS._LanguageID);
        values.put("TypeInfo", GRS._TypeInfo);
        values.put("TableName", GRS._TableName);
        values.put("Pavaragi", GRS._Pavaragi);

        long LastId = sql.insert("Response_tbl", null, values);
        sql.close();
        return LastId;
    }
}

Answer 1

您应该简单地将数据库文件复制到目标路径，而不是保存文件。

这将是faster和safer。

在将其从assets文件夹复制到data path时，确实应该使用相同的方法。

这一次，您应该将data path复制到SD card (要么将输入和输出路径参数化，要么编写另一个方法)。

等等。