Android Studio告訴我找不到該文件

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

    Button mBtn1 = (Button) findViewById(R.id.start_Quit_button); 
    mBtn1.setOnClickListener(new View.OnClickListener() { 
     @Override 
     public void onClick(View v) { 
      // TODO Auto-generated method stub 
      Log.i("clicks", "You Clicked B1"); 
      Intent i = new Intent(
        StartActivity.this, 
        MainActivity.class); 
      startActivity(i); 
     } 
    }); 
    Button mBtn2 = (Button) findViewById(R.id.start_Next_button); 
    mBtn2.setOnClickListener(new View.OnClickListener() { 
     @Override 
     public void onClick(View v) { 
      // TODO Auto-generated method stub 
      Log.i("clicks", "You Clicked B2"); 
      TextView username = (TextView) findViewById(R.id.login_text); 

      File root = new File(Environment.getExternalStorageDirectory().getAbsolutePath() + "/ExperimentLog"); 
      if (!root.exists()) { 
       root.mkdir(); 
      } 

      Username = username.getText().toString(); 


      save(root, Username); 

      Intent i = new Intent(
        StartActivity.this, 
        Test1_0.class); 
      startActivity(i); 
     } 
    }); 
} 

public void save(File dir, String string) { 
    try { 
     File filepath = new File(dir, Username + ".txt"); 
     FileWriter writer = new FileWriter(filepath); 
     writer.append(string); 
     writer.flush(); 
     writer.close(); 
    } catch (IOException e) { 
     e.printStackTrace(); 
    } 
} 
}

這是我的代碼。正如你所看到的，我希望第二個按鈕進入下一個活動並保存從editText start_Next_button獲得的文本。還有一種將字符串寫入創建的文件的保存方法。但是當我按在AVD按鈕，機器人工作室表明這一點：Android Studio告訴我找不到該文件

04-28 10:09:44.242 2379-2379/com.android.mick.encodingaidingexperiment W/System.err: java.io.FileNotFoundException: /sdcard/ExperimentLog/Name.txt: open failed: ENOENT (No such file or directory) 
04-28 10:09:44.242 2379-2379/com.android.mick.encodingaidingexperiment W/System.err:  at libcore.io.IoBridge.open(IoBridge.java:452) 
04-28 10:09:44.242 2379-2379/com.android.mick.encodingaidingexperiment W/System.err:  at java.io.FileOutputStream.<init>(FileOutputStream.java:87) 
04-28 10:09:44.242 2379-2379/com.android.mick.encodingaidingexperiment W/System.err:  at java.io.FileOutputStream.<init>(FileOutputStream.java:72) 
04-28 10:09:44.242 2379-2379/com.android.mick.encodingaidingexperiment W/System.err:  at java.io.FileWriter.<init>(FileWriter.java:42) 
04-28 10:09:44.242 2379-2379/com.android.mick.encodingaidingexperiment W/System.err:  at com.android.mick.encodingaidingexperiment.StartActivity.save(StartActivity.java:74) 
04-28 10:09:44.242 2379-2379/com.android.mick.encodingaidingexperiment W/System.err:  at com.android.mick.encodingaidingexperiment.StartActivity$2.onClick(StartActivity.java:61) 
04-28 10:09:44.242 2379-2379/com.android.mick.encodingaidingexperiment W/System.err:  at android.view.View.performClick(View.java:5198) 
04-28 10:09:44.242 2379-2379/com.android.mick.encodingaidingexperiment W/System.err:  at android.view.View$PerformClick.run(View.java:21147) 
04-28 10:09:44.242 2379-2379/com.android.mick.encodingaidingexperiment W/System.err:  at android.os.Handler.handleCallback(Handler.java:739) 
04-28 10:09:44.242 2379-2379/com.android.mick.encodingaidingexperiment W/System.err:  at android.os.Handler.dispatchMessage(Handler.java:95) 
04-28 10:09:44.242 2379-2379/com.android.mick.encodingaidingexperiment W/System.err:  at android.os.Looper.loop(Looper.java:148) 
04-28 10:09:44.242 2379-2379/com.android.mick.encodingaidingexperiment W/System.err:  at android.app.ActivityThread.main(ActivityThread.java:5417) 
04-28 10:09:44.242 2379-2379/com.android.mick.encodingaidingexperiment W/System.err:  at java.lang.reflect.Method.invoke(Native Method) 
04-28 10:09:44.242 2379-2379/com.android.mick.encodingaidingexperiment W/System.err:  at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:726) 
04-28 10:09:44.242 2379-2379/com.android.mick.encodingaidingexperiment W/System.err:  at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:616) 
04-28 10:09:44.242 2379-2379/com.android.mick.encodingaidingexperiment W/System.err: Caused by: android.system.ErrnoException: open failed: ENOENT (No such file or directory) 
04-28 10:09:44.242 2379-2379/com.android.mick.encodingaidingexperiment W/System.err:  at libcore.io.Posix.open(Native Method) 
04-28 10:09:44.242 2379-2379/com.android.mick.encodingaidingexperiment W/System.err:  at libcore.io.BlockGuardOs.open(BlockGuardOs.java:186) 
04-28 10:09:44.242 2379-2379/com.android.mick.encodingaidingexperiment W/System.err:  at libcore.io.IoBridge.open(IoBridge.java:438) 
04-28 10:09:44.242 2379-2379/com.android.mick.encodingaidingexperiment W/System.err: ... 14 more

BTW我用AVD的Galaxy Nexus運行Android 6.0

來源

2016-04-28 Mick

您添加了「READ_EXTERNAL_STORAGE」和「WRITE_EXTERNAL_STORAGE」權限嗎？ –

<？xml version =「1.0」encoding =「utf-8」？> <使用權限android：name =」android.permission.WRITE_EXTERNAL_STORAGE「/> <使用權限android：name =」android.permission.READ_EXTERNAL_STORAGE「/> – Mick

首先例外的是關於文件是不存在的，所以如果目錄中不存在，則需要創建該文件夾和文件。您需要一個try catch塊來處理FileNotFoundException。也可以使用Files.createFile(thePath);創建文件（如果不存在）。

來源

2016-04-28 10:30:28

您需要捕獲拋出異常大部分次，我希望這可以幫助你 –

剛剛嘗試這一點

File root = new File(Environment.getExternalStorageDirectory().getAbsolutePath() + "/ExperimentLog"+".txt");

，而不是

File root = new File(Environment.getExternalStorageDirectory().getAbsolutePath() + "/ExperimentLog");

來源

2016-04-28 10:53:45

嘗試添加/後ExperimentLog然後mkdir()或mkdirs()。

來源

2016-04-28 11:44:24 aborocz

Android Studio告訴我找不到該文件

回答

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