Restful更改状态码和返回文字

public void add(HttpServletRequest request,HttpServletResponse response,@RequestBody String evnInfo) throws SaveOrUpdateErrorException{
		* * *
		List<Environment> envList = environmentService.getByName(null, evnType, evnDescribe);
		if(null==envList || envList.size()==0){
			* * *
		}else{
			response.setHeader("Content-Type", "application/json");  
			response.setCharacterEncoding("UTF-8");
			response.setStatus(501);
			try {
				Writer writer = response.getWriter();
				writer.write("请检查输入的环境是否已存在");
				writer.close();
			} catch (IOException e1) {
				e1.printStackTrace();
			}
			throw new SaveOrUpdateErrorException("请检查输入的环境是否已存在");
		}
	}