如何逐行讀取文本文件？

Question

我的目標是能夠將我的應用程序保存到使用FileOutputStream創建的文本文件中的高分數。然後我希望能夠從文件讀取並將每行放入數組列表項。在使用InputStreamReader時，我可以將文本文件中的所有文本行加載到變量s中。我現在的問題是我想從文本文件中取出每行並將其保存到數組列表項中。我將如何實現這一目標？

Example string variables for high scores: 
    String myStr = "Ryan 150 hard \n"; 
    String myStr2 = "Andrew 200 Medium \n"; 
    public void saveClick(){ 

    try{ 

     //String myNum = Integer.toString(life); 

     FileOutputStream fOut = openFileOutput("storetext.txt", Context.MODE_PRIVATE); 
     OutputStreamWriter outputWriter = new OutputStreamWriter(fOut); 

     outputWriter.write(myStr); 
     outputWriter.write(myStr2); 
     outputWriter.close(); 
     /*OutputStreamWriter out = new OutputStreamWriter(openFileOutput(STORETEXT, 0)); 

     out.write(life); 

     out.close();*/ 

     Toast.makeText(getApplicationContext(), "Save Successful", Toast.LENGTH_LONG).show(); 

    } 
    catch(Throwable t){ 

     Toast.makeText(getApplicationContext(), "Save Unsuccessful", Toast.LENGTH_LONG).show(); 

    } 

} 

public void readFileInEditor(){ 

    try{ 

     FileInputStream fileIn = openFileInput("storetext.txt"); 

     InputStreamReader InputRead = new InputStreamReader(fileIn); 

     char [] inputBuffer = new char[READ_BLOCK_SIZE]; 
     String s = ""; 
     int charRead; 


     while ((charRead=InputRead.read(inputBuffer))>0){ 

      //char to string conversion 
      String readString = String.copyValueOf(inputBuffer,0,charRead); 

      s += readString; 

     } 

     InputRead.close(); 

     Toast.makeText(getApplicationContext(), "New Text: " + s , Toast.LENGTH_LONG).show(); 

     //myText.setText("" + s); 

     try{ 

      //life = Integer.parseInt(s); 

      //Toast.makeText(getApplicationContext(), "My Num: " + life , Toast.LENGTH_LONG).show(); 

     } 
     catch(NumberFormatException e){ 

      //Toast.makeText(getApplicationContext(), "Could not get number" + life , Toast.LENGTH_LONG).show(); 

     } 

    } 
    catch(java.io.FileNotFoundException e){ 

     //have not created it yet 

    } 

    catch(Throwable t){ 

     Toast.makeText(getApplicationContext(), "Exception: "+t.toString(), Toast.LENGTH_LONG).show(); 

    } 



} 

Answer 1

爲了讓您的生活更輕鬆，最好使用（1）BufferedReader::readline()方法，或者（2）Scanner::nextLine()方法。並將每行添加到for循環中的List<String>。

一個簡單的例子：

List<String> lines = new ArrayList<>(); 
String curLine = null; 

BufferedReader reader = new BufferedReader(new FileReader("storetext.txt")); 
while ((curLine = reader.readLine()) != null) { 
    lines.add(curLine); 
} 

Answer 2

使用BufferedReader來逐行讀取並將它們放入ArrayList中。