stringBuffer.append(str).append("\n");
stringBuffer.append(str).append(useSystemLineSeparator?System.getProperties().getProperty("line.separator"):"\n");
  public static String readFile(File file)  {        StringBuffer stringBuffer = new StringBuffer();    try    {      BufferedReader in = new BufferedReader(new FileReader(file));      String str = null;            try      {        while ((str = in.readLine()) != null)        {          stringBuffer.append(str).append("\n");        }      }      finally      {        if (in != null)        {          in.close();        }      }    }    catch(IOException exception)    {      throw new RuntimeException(exception);    }        int length = stringBuffer.length();    if(length > 0)    {      stringBuffer.deleteCharAt(length - 1);    }    return stringBuffer.toString();  }  