如何逐行读取文本文件？

Question

我的目标是能够将我的应用程序保存到使用FileOutputStream创建的文本文件中的高分数。然后我希望能够从文件读取并将每行放入数组列表项。在使用InputStreamReader时，我可以将文本文件中的所有文本行加载到变量s中。我现在的问题是我想从文本文件中取出每行并将其保存到数组列表项中。我将如何实现这一目标？

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

为了让您的生活更轻松，最好使用（1）BufferedReader::readline()方法，或者（2）Scanner::nextLine()方法。并将每行添加到for循环中的List<String>。

一个简单的例子：

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来逐行读取并将它们放入ArrayList中。