ajax后台处理响应（java）

public static final void sendAsJson(HttpServletResponse response, String str)  {    response.setContentType("application/json;charset=UTF-8");    if (null != str)      try {        response.getWriter().write(str);      } catch (IOException e) {        e.printStackTrace();      }  }  public static final void sendAsText(HttpServletResponse response, String str)  {    response.setContentType("text/html;charset=UTF-8");    if (null != str)      try {        response.getWriter().write(str);      } catch (IOException e) {        e.printStackTrace();      }  }