文件方式保存数据，保存路径为/data/data/<packagename>/files/。有两种模式：MODE_PRIVATE 和 MODE_APPEND，其中 MODE_PRIVATE 是默认的操作模式，表示当指定同样文件名的时候，所写入的内容将会覆盖原文件中的内容，而 MODE_APPEND 则表示如果该文件已存在就往文件里面追加内容，不存在就创建新文件。

1 public void save() { 2     String data = "Data to save"; 3     FileOutputStream out = null; 4     BufferedWriter writer = null; 5     try { 6     out = openFileOutput("data", Context.MODE_PRIVATE); 7     writer = new BufferedWriter(new OutputStreamWriter(out)); 8     writer.write(data); 9     } catch (IOException e) {10         e.printStackTrace();11     } finally {12     try {13     if (writer != null) {14     writer.close();15     }16     } catch (IOException e) {17 e.printStackTrace();18 }19 }20 }

1 public String load() { 2 FileInputStream in = null; 3 BufferedReader reader = null; 4 StringBuilder content = new StringBuilder(); 5 try { 6 in = openFileInput("data"); 7 reader = new BufferedReader(new InputStreamReader(in)); 8 String line = ""; 9 while ((line = reader.readLine()) != null) {10 content.append(line);11 }12 } catch (IOException e) {13 e.printStackTrace();14 } finally {15 if (reader != null) {16 try {17 reader.close();18 } catch (IOException e) {19 e.printStackTrace();20 }21 }22 }23 return content.toString();24 }