相关疑难解决方法(0)

我想在sdcard或外部SD卡中创建数据库为此我已经尝试了这个代码并使用这个我已经在SD卡中成功创建了数据库,但在logcat中它给了我如下警告

logcat的

07-18 14:18:22.140:W/FileUtils(8595):chmod失败(/ mnt/sdcard/peakmedia/DB_PMD):libcore.io.ErrnoException:chmod failed:EPERM(不允许操作)

DB_Helper.java

public class DB_Helper extends SQLiteOpenHelper
{

    public DB_Helper(Context context) 
    {   
        super(context, Environment.getExternalStorageDirectory().getAbsolutePath() 
                       + File.separator + DB_Constant.DB.FILE_DIR 
                       + File.separator + DB_Constant.DB.DATABASENAME, null, DB_Constant.DB.DB_VERSION);

    }

    @Override
    public void onCreate(SQLiteDatabase db) 
    {
        String  query=String.format(DB_Constant.CREATE_TABLE_QUERY.CREATE_MYFILES_TABLE);
        db.execSQL(query);


        query=String.format(DB_Constant.CREATE_TABLE_QUERY.CREATE_MYUSERS_TABLE);
        db.execSQL(query);

        query=String.format(DB_Constant.CREATE_TABLE_QUERY.CREATE_MYPLAYLIST_TABLE);
        db.execSQL(query);

        query=String.format(DB_Constant.CREATE_TABLE_QUERY.CREATE_MYDEVICE_TABLE);
        db.execSQL(query);

    }

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

                db.execSQL("DROP TABLE IF EXISTS "+ DB_Constant.TABLE.MYFILES);
                onCreate(db);

                db.execSQL("DROP TABLE IF EXISTS "+ DB_Constant.TABLE.MYUSERS);
                onCreate(db);

                db.execSQL("DROP TABLE IF EXISTS "+ DB_Constant.TABLE.MYPLAYLIST); …