Question

首先，我需要在内部存储中创建文本文件（如果文件不存在），然后逐行读取值到数组中。我不明白我做错了什么，为什么我从内存中读取的内容并没有检测到我的文件，我应该如何解决？（我想创建文件并写入它是正确的）

我希望我的数据文件如何：

data
data
data
data
data
data

我如何将值写入文件：

        FileOutputStream fOut = null;
        try {
            fOut = openFileOutput("VilniusWeatherVU.txt",MODE_WORLD_READABLE);
        } catch (FileNotFoundException e) {
            e.printStackTrace();
        }
        String v33 = "data";
        String v12 = "data";
        String v3 = "data";
        String v11 = "data";
        String v6 = "data";
        String v1 = "data";

        try {
            fOut.write(v33.getBytes());
        } catch (IOException e) {
            e.printStackTrace();
        }
        try {
            fOut.write(v12.getBytes());
        } catch (IOException e) {
            e.printStackTrace();
        }
        try {
            fOut.write(v3.getBytes());
        } catch (IOException e) {
            e.printStackTrace();
        }
        try {
            fOut.write(v11.getBytes());
        } catch (IOException e) {
            e.printStackTrace();
        }
        try {
            fOut.write(v6.getBytes());
        } catch (IOException e) {
            e.printStackTrace();
        }
        try {
            fOut.write(v1.getBytes());
        } catch (IOException e) {
            e.printStackTrace();
        }

        try {
            fOut.close();
        } catch (IOException e) {
            e.printStackTrace();
        }

我如何阅读价值观：

String[] array = new String[6];
        int index = 0;
        try{
            // Open the file that is the first
            // command line parameter
            FileInputStream fstream = new FileInputStream("VilniusWeatherVU.txt");
            // Get the object of DataInputStream
            DataInputStream in = new DataInputStream(fstream);
            BufferedReader br = new BufferedReader(new InputStreamReader(in));
            String strLine;
            //Read File Line By Line
            while ((strLine = br.readLine()) != null)   {
                // Print the content on the console
                //System.out.println (strLine);
                array[index]=strLine;
                index++;
            }
            //Close the input stream
            in.close();
        }catch (Exception e){//Catch exception if any
            System.err.println("Error: " + e.getMessage());
        }

我如何检查我的阵列：

    for (int i = 0; i <6; i++){
       Log.v(LOG_TAG, "CHECK IF IT WORKED " + array[i]);
   }

我的logcat说：

11-24 16:06:56.886      359-359/app.sunshine.android.example.com.sunshine W/System.err﹕ Error: /VilniusWeatherVU.txt (No such file or directory)
11-24 16:06:56.895      359-359/app.sunshine.android.example.com.sunshine V/MyNewMain﹕ CHECK IF IT WORKED null
11-24 16:06:56.895      359-359/app.sunshine.android.example.com.sunshine V/MyNewMain﹕ CHECK IF IT WORKED null
11-24 16:06:56.895      359-359/app.sunshine.android.example.com.sunshine V/MyNewMain﹕ CHECK IF IT WORKED null
11-24 16:06:56.895      359-359/app.sunshine.android.example.com.sunshine V/MyNewMain﹕ CHECK IF IT WORKED null
11-24 16:06:56.895      359-359/app.sunshine.android.example.com.sunshine V/MyNewMain﹕ CHECK IF IT WORKED null
11-24 16:06:56.895      359-359/app.sunshine.android.example.com.sunshine V/MyNewMain﹕ CHECK IF IT WORKED null

请不要让我独自一人:(

Frunk要求：

我试图以不同的方式从文件中读取：

        FileInputStream fin = null;
        try {
            fin = openFileInput("VilniusWeatherVU.txt");
        } catch (FileNotFoundException e) {
            e.printStackTrace();
        }

        int c;
        String temp="";
        try {
            while( (c = fin.read()) != -1){
                temp = temp + Character.toString((char)c);
            }
        } catch (IOException e) {
            e.printStackTrace();
        }
//string temp contains all the data of the file.
        try {
            fin.close();
        } catch (IOException e) {
            e.printStackTrace();
        }

然后我用logcat来检查：

Log.v(LOG_TAG, "CHECK IF IT WORKED " + temp);

我得到的是：

11-24 16:24:38.345      334-334/app.sunshine.android.example.com.sunshine V/MyNewMain﹕ CHECK IF IT WORKED datadatadatadatadatadata

Answer 1

尝试使用openFileInput（＆＃34; VilniusWeatherVU.txt＆＃34;）来读取你的文件txt。

例如：

FileInputStream fileInputStream= openFileInput("VilniusWeatherVU.txt");
InputStreamReader inputStreamReader = new InputStreamReader(fileInputStream);
BufferedReader bufferedReader = new BufferedReader(inputStreamReader);
StringBuilder stringBuilder= new StringBuilder();
String line;
while ((line = bufferedReader.readLine()) != null) {
    stringBuilder.append(line);
}

Answer 2

public class MyFragment extends Fragment
    {

        @Override
        public View onCreateView(LayoutInflater inflater, ViewGroup container,
                Bundle savedInstanceState)
        {
            view = inflater.inflate(R.layout.myfragment, container, false);


            writeFile("text.txt", view.getContext());
            String[] test = readFile("text.txt", view.getContext());
            if(test==null)
            {
              // error to read file or file dont exists
            }else
            {
              //read file
            }    
            return view;
        }

 public static String   newline = System.getProperty("line.separator");

// write file
private void writeFile(String filename, Context context)
{

    File file = new File(context.getFilesDir(), filename);

    // write data if file dont exists
    if (!file.exists())
    {
        String string = "data" + newline + "data" + newline + "data"
                + newline + "data" + newline + "data" + newline + "data"
                + newline;

        FileOutputStream outputStream;

        try
        {
            outputStream = context.openFileOutput(filename,
                    Context.MODE_PRIVATE);
            outputStream.write(string.getBytes());
            outputStream.close();

        } catch (Exception e)
        {
            e.printStackTrace();
        }
    }
}

// read file and convert data to String array
private String[] readFile(String filename, Context context)
{
    try
    {
        File file = new File(context.getFilesDir(), filename);
        if (!file.exists())
        {
            return null;
        }
        FileInputStream fis = new FileInputStream(file);
        byte[] dataByte = new byte[(int) file.length()];
        fis.read(dataByte);
        fis.close();
        String data = new String(dataByte);
        // slit string with newline <\n>

        return data.split(newline);
    } catch (Exception e)
    {
        e.printStackTrace();
    }
    return null;


}
}

Answer 3

fOut = openFileOutput("VilniusWeatherVU.txt",MODE_WORLD_READABLE);

与

不符

FileInputStream fstream = new FileInputStream("VilniusWeatherVU.txt");

更好：要阅读文件，请使用getFilesDir()作为存储文件的目录的完整路径。

读取文件到数组后的android NULL值

3 个答案: