public String getOrderEvidence(Map<String, String> parameters){
        String json= JSON.toJSONString(parameters);
        try {
            String postURL = GlobalConstant.ORDER_EVIDENCE_URL;
            PostMethod postMethod = null;
            postMethod = new PostMethod(postURL) ;
            postMethod.setRequestHeader("Content-Type", "application/x-www-form-urlencoded;charset=utf-8") ;
            //参数设置，需要注意的就是里边不能传NULL，要传空字符串

            NameValuePair[] data = {
                    new NameValuePair("parameters",json)
            };
            postMethod.setRequestBody(data);
            //连接超时设置为4秒
            RequestConfig requestConfig = RequestConfig.custom().setSocketTimeout(2000).setConnectTimeout(2000).build();
            HttpPost httpPost = new HttpPost(postURL);
            httpPost.setConfig(requestConfig);
            org.apache.commons.httpclient.HttpClient httpClient = new org.apache.commons.httpclient.HttpClient();
            int response = httpClient.executeMethod(postMethod); // 执行POST方法
            String result = postMethod.getResponseBodyAsString() ;
            JSONObject jsonObject = new JSONObject(result);
            if(jsonObject!=null){
                JSONObject dataObject = jsonObject.getJSONObject("data");
                if(dataObject!=null){
                    Integer errCode = dataObject.getInt("errCode");
                    /**
                     * 错误码 错误码定义
                     * 0 SUCCESS
                     * -1 模型不存在(表里没数据)
                     * -2 上链信息不存在(表里没数据)
                     * -3 数据未上链
                     * -4 查询信息缺少appkey信息(入参缺少appkey)
                     * -5 查询信息缺少primaryKey信息(入参缺少primaryKey)
                     * -6 查询信息缺少tableName信息(入参缺少tableName)
                     */
                    if(errCode == 0){
                        String evidenceCode = dataObject.getString("data");
                        return evidenceCode;
                    }else{
                        log.error("====getOrderEvidence区块链错误码-1 模型不存在-2 上链信息不存在(表里没数据)-3 数据未上链 -4 参数缺少appkey -5 缺少primaryKey -6 缺少tableName==========" + errCode);
                        return "";
                    }
                }else{
                    return "";
                }
            }else{
                return "";
            }


        } catch (Exception e) {
            log.error("getOrderEvidence请求异常"+e.getMessage(),e);
            return "";
        }
    }