Question

我第一次使用android中的SQLite开发。 Currenly，我有现有的sqlite数据库，我想在资产文件夹中复制粘贴，然后阅读它。但我面临以下问题：

我的位置：

09-21 13:08:23.725: I/Database(11660): sqlite returned: error code = 14, msg = cannot open file at source line 25467
09-21 13:08:23.784: E/Database(11660): sqlite3_open_v2("/data/data/YOUR_PACKAGE/databases/myDBName", &handle, 1, NULL) failed
09-21 13:08:23.866: I/In createDataBase();IOException(11660): myDBName

我在google上搜索了它，得到了解决方案并根据它更新了我的代码，但仍面临问题。我无法解决问题所在。

我的代码如下：

public class DataBaseHelper extends SQLiteOpenHelper{

private static String DB_PATH = "/data/data/com.example.androidtestapplication/databases/";

private static String DB_NAME = "myDBName";

private SQLiteDatabase myDataBase; 

private final Context myContext;

public DataBaseHelper(Context context) {

    super(context, DB_NAME, null, 1);
    this.myContext = context;
}   
public void createDataBase() throws IOException{

    boolean dbExist = checkDataBase();

    if(dbExist){
        //do nothing - database already exist
    }
    else{
            this.getReadableDatabase();

        try {

            copyDataBase();

        } 
            catch (IOException e) {

            //throw new Error("Error copying database");
            Log.i("In createDataBase();IOException",e.getMessage());

        }
    }

}

private boolean checkDataBase(){

    SQLiteDatabase checkDB = null;

    try{
        String myPath = DB_PATH + DB_NAME;
        checkDB = SQLiteDatabase.openDatabase(myPath, null, SQLiteDatabase.OPEN_READONLY);

    }catch(SQLiteException e){

        //database does't exist yet.

    }

    if(checkDB != null){

        checkDB.close();

    }

    return checkDB != null ? true : 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 = DB_PATH + 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;
    while ((length = myInput.read(buffer))>0){
        myOutput.write(buffer, 0, length);
    }

    //Close the streams
    myOutput.flush();
    myOutput.close();
    myInput.close();

}

public void openDataBase() throws SQLException{

    //Open the database
    String myPath = DB_PATH + DB_NAME;
    myDataBase = SQLiteDatabase.openDatabase(myPath, null, SQLiteDatabase.OPEN_READONLY);

}

@Override
public synchronized void close() {

        if(myDataBase != null)
            myDataBase.close();

        super.close();

}

@Override
public void onCreate(SQLiteDatabase db) {

}

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

}
}

MainActivity.java文件是：

public class MainActivity extends Activity {

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

    DataBaseHelper myDbHelper = new DataBaseHelper(this);
    myDbHelper = new DataBaseHelper(this);

    try {
        myDbHelper.createDataBase();
    } 
    catch (IOException ioe) {
        //throw new Error("Unable to create database");
        Log.i("In MainActivity:IOException",ioe.getMessage());
    }

    try {
        myDbHelper.openDataBase();

    }
    catch(SQLException sqle){

        //throw sqle;
        Log.i("In MainActivity:SQLException",sqle.getMessage());

    }
}
}

我还在清单文件中添加了以下权限：

<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"/>

我已按照本教程操作： http://www.reigndesign.com/blog/using-your-own-sqlite-database-in-android-applications/

请告诉我这里缺少的东西。

请帮助我......提前致谢... :)

sqlite返回：错误代码= 14，msg =无法在源行25467打开文件

0 个答案: