在Android中讀取SD卡中的文本文件時出錯

我試圖從SD卡中逐行讀取文本文件。雖然我在java編譯獨立的代碼工作，在eclipse中的這個代碼給出了錯誤。代碼保持循環通過一些不是我的文本文件。在Android中讀取SD卡中的文本文件時出錯

@Override 
protected void onCreate(Bundle savedInstanceState) { 
    super.onCreate(savedInstanceState); 
    setContentView(R.layout.layout_ardtxt); 
//********************* 
    Toast.makeText(getApplicationContext(), "start" , Toast.LENGTH_LONG).show(); 
    Log.d("chk","app start"); 

    File directory = new File(Environment.getExternalStorageDirectory()+File.separator+"kk"); 
    directory.mkdirs(); 

    Log.d("mytxt app App", Environment.getExternalStorageDirectory()+File.separator+"kk"); 
    fileexists = new File(Environment.getExternalStorageDirectory()+File.separator+"kk"+File.separator, "Sample1.txt"); 
     if (fileexists.exists()) { 
     //Do action 
      Toast.makeText(getApplicationContext(), "subject file exists" , Toast.LENGTH_LONG).show(); 
      System.out.println("file exists so can be used by us"); 
     Log.d("Ketan check", "Sample1.txt exists"); 
     try { 
      Readtxtfile(); 
     }catch (FileNotFoundException e) { 
      // TODO Auto-generated catch block 
     Log.d(gg,"Exception : file not found"); 
      e.printStackTrace(); 
      Toast.makeText(getApplicationContext(), "ketan file not found" , Toast.LENGTH_LONG).show(); 
     } 

     }else{ 
      Toast.makeText(getApplicationContext(), "sorry no file or path" , Toast.LENGTH_LONG).show(); 
      Log.d("App file check", "App File not found"); 
     } 

} 

public void Readtxtfile() throws FileNotFoundException { 
    Log.i(gg, "sub readtextfile started"); 

    Toast.makeText(getApplicationContext(), "start reading file" , Toast.LENGTH_SHORT).show(); 
    FileInputStream fis = new FileInputStream(fileexists); 
    Scanner scanner = new Scanner(fis); 
    Log.i(gg,"Scanner started"); 
    System.out.println("Reading file line by line in Java using Scanner"); 

    while(scanner.hasNextLine()){ 
String tt = scanner.nextLine(); 
Log.d("app", "inside scanner while loop"); 
Log.i(tt,tt); 

    } 

    scanner.close(); 
    } ; 
}

我已經添加了讀寫SD卡的權限。 Logcat輸出如下。

11-25 11:08:46.626: E/Trace(805): error opening trace file: No such file or directory (2) 
11-25 11:08:47.456: D/chk(805): app start 
11-25 11:08:47.456: D/mytxt app App(805): /mnt/sdcard/kk 
11-25 11:08:47.525: I/System.out(805): file exists so can be used by us 
11-25 11:08:47.525: D/Ketan check(805): Sample1.txt exists 
11-25 11:08:47.536: I/my app(805): sub readtextfile started 
11-25 11:08:47.628: I/my app(805): Scanner started 
11-25 11:08:47.628: I/System.out(805): Reading file line by line in Java using Scanner 
11-25 11:08:47.656: D/app(805): inside scanner while loop 
11-25 11:08:47.656: I/on early-init(805): on early-init 
11-25 11:08:47.722: D/app(805): inside scanner while loop 
11-25 11:08:47.722: I/export EXTERNAL_STORAGE /mnt/sdcard(805):  export EXTERNAL_STORAGE /mnt/sdcard 
11-25 11:08:47.726: D/app(805): inside scanner while loop 
11-25 11:08:47.726: I/mkdir /mnt/sdcard 0000 system system(805):  mkdir /mnt/sdcard 0000 system system 
11-25 11:08:47.726: D/app(805): inside scanner while loop 
11-25 11:08:47.726: I/# for backwards compatibility(805):  # for backwards compatibility 
11-25 11:08:47.735: D/app(805): inside scanner while loop 
11-25 11:08:47.735: I/symlink /mnt/sdcard /sdcard(805):  symlink /mnt/sdcard /sdcard 
11-25 11:08:47.735: D/app(805): inside scanner while loop 
11-25 11:08:47.748: D/app(805): inside scanner while loop 
11-25 11:08:47.748: I/on boot(805): on boot 
11-25 11:08:47.748: D/app(805): inside scanner while loop 
11-25 11:08:47.748: I/setprop ARGH ARGH(805):  setprop ARGH ARGH 
11-25 11:08:47.760: D/app(805): inside scanner while loop 
11-25 11:08:47.760: I/setprop net.eth0.gw 10.0.2.2(805):  setprop net.eth0.gw 10.0.2.2 
11-25 11:08:47.766: D/app(805): inside scanner while loop 
11-25 11:08:47.766: I/setprop net.eth0.dns1 10.0.2.3(805):  setprop net.eth0.dns1 10.0.2.3 
11-25 11:08:47.786: D/app(805): inside scanner while loop 
11-25 11:08:47.786: I/setprop net.gprs.local-ip 10.0.2.15(805):  setprop net.gprs.local-ip 10.0.2.15 
11-25 11:08:47.896: D/app(805): inside scanner while loop 
11-25 11:08:47.906: I/setprop ro.radio.use-ppp no(805):  setprop ro.radio.use-ppp no 
11-25 11:08:47.906: D/app(805): inside scanner while loop 
11-25 11:08:47.906: I/setprop ro.build.product generic(805):  setprop ro.build.product generic 
11-25 11:08:47.928: D/app(805): inside scanner while loop 
11-25 11:08:47.947: I/setprop ro.product.device generic(805):  setprop ro.product.device generic 
11-25 11:08:47.947: D/app(805): inside scanner while loop 
11-25 11:08:47.976: D/app(805): inside scanner while loop 
11-25 11:08:47.976: I/# fake some battery state(805): # fake some battery state 
11-25 11:08:48.030: D/app(805): inside scanner while loop 
11-25 11:08:48.030: I/setprop status.battery.state Slow(805):  setprop status.battery.state Slow 
11-25 11:08:48.046: D/app(805): inside scanner while loop 
11-25 11:08:48.046: I/setprop status.battery.level 5(805):  setprop status.battery.level 5 
11-25 11:08:48.127: D/app(805): inside scanner while loop 
11-25 11:08:48.127: I/setprop status.battery.level_raw 50(805):  setprop status.battery.level_raw 50 
11-25 11:08:48.127: D/app(805): inside scanner while loop 
11-25 11:08:48.127: I/setprop status.battery.level_scale 9(805):  setprop status.battery.level_scale 9 
....... and like this goes on.

來源

2013-11-25 Madiya

沒有ü添加的權限？它無法正確找到路徑 – KOTIOS

已經爲讀取和寫入兩者添加了權限。它也可以找到sample1.txt文件，但不是通過文件循環來讀取文件文本，而是給出一些垃圾。 – Madiya

注意，垃圾只有在代碼進入while循環後纔會啓動，如logcat所示。是用於閱讀Android中的文本文件的java掃描儀嗎？可能是java掃描儀錯了。 – Madiya

you can use this to read file line by line 

File sdcard = Environment.getExternalStorageDirectory(); 

//Get the text file 
File file = new File(sdcard,"file.txt"); 

//Read text from file 
StringBuilder text = new StringBuilder(); 

try { 
    BufferedReader br = new BufferedReader(new FileReader(file)); 
    String line; 

    while ((line = br.readLine()) != null) { 

Log.i(line,line); 
    } 
} 
catch (IOException e) { 
    //You'll need to add proper error handling here 
}

來源

2013-11-25 07:49:50

我會嘗試一下併發布結果。 – Madiya

試過了。給出相同的輸出而不是從文本文件輸出。 – Madiya

您試圖訪問未創建的文件。
使用code.or手動將文本文件導入到/ mnt/SD卡/ KK

File directory = new File(Environment.getExternalStorageDirectory()+File.separator+"kk"); 
directory.mkdirs(); 

Log.d("mytxt app App", Environment.getExternalStorageDirectory()+File.separator+"kk"); 
fileexists = new File(Environment.getExternalStorageDirectory()+File.separator+"kk"+File.separator, "Sample1.txt"); 



try { 
     if (!fileexists.exists()) { 
      Log.d("Ketan check", "asdasdasdasdsadsd"); 
     fileexists.createNewFile(); 
     } 
    } catch (IOException e1) { 
     // TODO Auto-generated catch block 
     e1.printStackTrace(); 
    }

來源

2013-11-25 08:02:15

文件已存在，因爲文件exixts調用返回true。如果文件不存在，則根本不會執行Readtxtfile（）。我已經在該位置手動複製了該文件。 – Madiya

您是否添加了這些權限 –

是的。它從一開始就增加了權利。謝謝。 – Madiya

在Android中讀取SD卡中的文本文件時出錯

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