```java
   public boolean sauvegarder(String fileName, String data) {
        FileOutputStream output = null;
        try {
            output = openFileOutput(fileName, MODE_PRIVATE);
            output.write(data.getBytes());
            if(output != null) {
                output.close();
            }
            return true;
        } catch (FileNotFoundException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        }
        return false;
    }

    public String charger(String fileName){
        String value = null;
        FileInputStream inputStream= null;
        try {
            inputStream = openFileInput(fileName);

        StringBuilder stringb= new StringBuilder();
        int content;

        while ((content=inputStream.read())!=-1){
            value = String.valueOf(stringb.append((char)content));
        }
        } catch (FileNotFoundException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        }
        return value ;
    }
```