restTemplate 的post请求解决 乱码问题

  HttpHeaders headers = new HttpHeaders();
        MediaType type = MediaType.parseMediaType("application/json; charset=UTF-8");
//  请勿轻易改变此提交方式，大部分的情况下，提交方式都是表单提交
        headers.setContentType(type);
        headers.add("Accept", MediaType.APPLICATION_JSON.toString());
        JSONObject jsonObj = new JSONObject();
        jsonObj.put("uid",sendMessage.getUId());
        jsonObj.put("message",sendMessage.getMessage());
        jsonObj.put("param",sendMessage.getParam());
        //  封装参数，千万不要替换为Map与HashMap，否则参数无法传递
        MultiValueMap params = new LinkedMultiValueMap();

     HttpEntity requestEntity = new HttpEntity(jsonObj.toString(), headers);
//  执行HTTP请求
        ResponseEntity exchange = restTemplate.exchange(url, HttpMethod.POST, requestEntity, String.class);