Question

我正在尝试从文件中读取内容，但我找不到文件异常。

请帮帮我。我正在使用下面的代码。

 File f = new File("C:/sample/welcome.txt"); //working
 System.out.println("File path  ="+f.getPath());                              
 System.out.println("File name  = "+f.getName());
 System.out.println("File size = "+f.length());
 String ret = "";

 HttpURLConnection connection = null;

 try {

      int size = (int) f.getName().length();
      byte[] data = new byte[size];
      String _contrainerName1 ="/development";
      // String content = new String("This is my first upload to dropbox");
      //String fileName ="test17.txt";

      try {
          InputStream inputStream =  new FileInputStream(f.getName());

          if ( inputStream != null ) {
             DataInputStream in1 = new DataInputStream(inputStream);
             // InputStreamReader inputStreamReader = new InputStreamReader(inputStream);
             BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(in1));

             String receiveString = "";
             StringBuilder stringBuilder = new StringBuilder();

             while ( (receiveString = bufferedReader.readLine()) != null ) {
                  stringBuilder.append(receiveString);
             }

             inputStream.close();
             ret = stringBuilder.toString();
        }
    } catch (FileNotFoundException e) {
      e.printStackTrace();
      System.out.println("login activity");

    } catch (IOException e) {
      e.printStackTrace();
      System.out.println("login activity");
    }

Answer 1

如果您尝试在Windows文件系统中读取文件，则应使用双重反弹：

  File f = new File("C:\\sample\\welcome.txt");

此外，您可以实例化直接传递File对象的FileInputStream

  InputStream inputStream =  new FileInputStream(f);

Answer 2

要做的第一件事是检查C：\驱动器中是否确实存在该文件。

C：\ drive

C：/sample/welcome.txt

反斜杠是第一个提示：）

Answer 3

     try {

        File sdcard = Environment.getExternalStorageDirectory();
        File file = new File(sdcard, "location/of/filename.txt");
        BufferedReader r = new BufferedReader(new FileReader(file));
        StringBuilder total = new StringBuilder();
        String line;
        while ((line = r.readLine()) != null) {
            total.append(line);
            total.append('\n');
        }
        String ttt = total.toString();
        TextView txt = (TextView)findViewById(R.id.txt);
        txt.setText(ttt);



        r.close();
        Log.d("File", "File contents: " + total);
    } catch (Exception e) {
        e.printStackTrace();
    }

在android

中读取文件的确切代码

Answer 4

CommonsWire如何说，在Android C:中并不存在。您有 getExternalStorageDirectory 。试试这个：

File myfile = new File(Environment.getExternalStorageDirectory() + File.separator + "myFile.txt");

文件未找到异常，用于读取文件内容

4 个答案: