bufferedwriter在android中不工作

我在我的资产文件夹中存储了一个文件。我阅读了文件，并根据用户要求将某些数据附加到文件中。然后将文件存储到emulator的数据目录中。我正在为此使用bufferedwriter，但它不起作用，在数据文件夹中生成的结果文件大小为0kb。文件正在制作中。 这是我的密码

InputStream myInput = this.getAssets().open("exportformat.txt");
        BufferedReader inputStream = new BufferedReader(
                new InputStreamReader(myInput));

        String outFileName = "/data/data/packagename/attachment.txt";
        OutputStream myOutput = new FileOutputStream(outFileName);
        BufferedWriter outStream = new BufferedWriter(
                new OutputStreamWriter(myOutput));
        String datafromfile;
        while ((datafromfile = inputStream.readLine()) != null) {
            StringBuffer sb = new StringBuffer(datafromfile);
            if (datafromfile.equals("DTSTART:"))
                sb.append(details[2]);
            if (datafromfile.equals("DTEND:"))
                sb.append(details[3]);
            if (datafromfile.equals("SUMMARY:"))
                sb.append(details[0]);
            if (datafromfile.equals("DESCRIPTION:"))
                sb.append(details[1]);
            datafromfile = sb.toString();

            outStream.write(datafromfile);
            outStream.newLine();
        }

        // Close the streams
        myOutput.flush();
        myOutput.close();
        outStream.close();
        inputStream.close();
        myInput.close();
    } catch (Exception e) {
            e.printStackTrace();
    }
}

我试过调试。正在正确读取数据，只有写入操作不起作用

先谢谢你

答复:

以下代码正在运行：

InputStream myInput = this.getAssets().open("exportformat.txt");
        BufferedReader inputStream = new BufferedReader(
                new InputStreamReader(myInput));

        String outFileName = "/data/data/com.helios.NauticDates/attachment.ics";
        File checkfile = new File(outFileName);
        if(checkfile.exists()){
            checkfile.delete();
        }
        for(int i =0 ;i<4;i++){
            if(details[i].equals("null"))
                details[i]=" ";
        }
        FileOutputStream myOutput = new FileOutputStream(outFileName);
        String datafromfile;
        while ((datafromfile = inputStream.readLine()) != null) {
            StringBuffer sb = new StringBuffer(datafromfile);
            if (datafromfile.equals("DTSTART:"))
                sb.append(details[2]);
            if (datafromfile.equals("DTEND:"))
                sb.append(details[3]);
            if (datafromfile.equals("SUMMARY:"))
                sb.append(details[0]);
            if (datafromfile.equals("DESCRIPTION:"))
                sb.append(details[1]);
            if(datafromfile.equals("CATEGORIES:"))
                sb.append(details[4]);
            datafromfile = sb.toString();
            datafromfile+="\n";
             byte[] temp = datafromfile.getBytes();
             myOutput.write(temp);
        }

        // Close the streams
        myOutput.flush();
        myOutput.close();
        inputStream.close();
        emailintent.putExtra(Intent.EXTRA_STREAM,Uri.parse(outFileName));
        emailintent.setType("plain/text");
        startActivity(Intent.createChooser(emailintent, "Send mail..."));
    } catch (Exception e) {
            e.printStackTrace();
    }

InputStream myInput=this.getAssets（）.open（“exportformat.txt”）；
BufferedReader inputStream=新的BufferedReader(
新的InputStreamReader（myInput））；
字符串outFileName=“/data/data/com.helios.NauticDates/attachment.ics”；
文件checkfile=新文件（outFileName）；
if（checkfile.exists（））{
checkfile.delete（）；
}
对于（int i=0；i尝试使用
FileWriter
而不是
FileOutputStream
，如下所示：

FileWriter myOutput = new FileWriter(outFileName);
BufferedWriter outStream = new BufferedWriter(myOutput);

我有一个代码，其中我将sqlite数据库从assets文件夹复制到android系统的data文件夹

private String DB_PATH =mycontext.getPackageName() + "/databases/";
private static String DB_NAME = "PartyDetails.sqlite"; 
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 byte to inputfile to 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();

}

希望有帮助：-）