写入数据

public void write(String text){
        FileOutputStream fileOutputStream = null;

        try {
            fileOutputStream = openFileOutput("test.txt", MODE_PRIVATE);
            fileOutputStream.write(text.getBytes());
        } catch (Exception e) {
            System.out.println("===============上：存储报错了！================");
            e.printStackTrace();
        } finally {
            if (fileOutputStream != null) {
                try {
                    fileOutputStream.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
        }
    }

读取数据

 public void read(){

        FileInputStream fileInputStream = null;
        Reader reader = null;
        BufferedReader bufferedReader = null;
        try {
            fileInputStream = context.openFileInput("test.txt");
            reader = new InputStreamReader(fileInputStream);// 字符流
            bufferedReader = new BufferedReader(reader); //
            String temp;
            /*data = null;
            data =new ArrayList<>();*/
            while ((temp = bufferedReader.readLine()) != null) {
                if(temp.equals("")){
                    continue;
                }
                data.add(temp);
            }
        } catch (Exception e) {
            System.out.println("------------上：读取报错了！-----------------");
            e.printStackTrace();
        } finally {
            if (reader != null) {
                try {
                    reader.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
            if (fileInputStream != null) {
                try {
                    fileInputStream.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
            if (bufferedReader != null) {
                try {
                    bufferedReader.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
        }

    }