private void returnJson(HttpServletRequest request,ServletResponse response, ResultModel ResultModel) throws IOException {
//把返回值输出到客户端
HttpServletRequest httpServletRequest = (HttpServletRequest) request;
HttpServletResponse httpServletResponse = (HttpServletResponse) response;
httpServletResponse.setHeader("Access-control-Allow-Origin", httpServletRequest.getHeader("Origin"));
httpServletResponse.setHeader("Access-Control-Allow-Methods", "GET,POST,OPTIONS,PUT,DELETE");
httpServletResponse.setHeader("Access-Control-Allow-Headers", httpServletRequest.getHeader("Access-Control-Request-Headers"));
response.setContentType("application/json; charset=utf-8");
response.setCharacterEncoding("UTF-8");
ServletOutputStream outputStream = response.getOutputStream();
outputStream.write(JsonTools.objToJson(ResultModel).getBytes());
outputStream.flush();
outputStream.close();
}