要删除emqx的某个clientid连接，

1、可以通过界面直接手动删除。

 

 

2、可以通过命令行：

查询所有clientid
# ./bin/emqx_ctl clients list
删除某个clientid
# ./bin/emqx_ctl clients kick <Clientid>

进行删除。

3、还可以通过Java接口调用删除：

我的emqx 版本是 4.0.4 。删除地址为 

http://127.0.0.1:18083/api/v4/clients/clientid_test

其他版本访问地址可能有所不同，请注意。

 @Override
    public ResultDTO deleteClientId(String clientid){
        log.info("deleteClientId 设备禁用，下行指令剔除原mqtt的clientid连接，入参clientid： {}", clientid);
        try {
                /* 传入的clientid 可能有特殊字符，先进行字符转换 */
                clientid = URLEncoder.encode(clientid,"UTF-8");
        } catch (UnsupportedEncodingException e) {
                e.printStackTrace();
                return ResultDTO.getFailure();
        }
        // 这里拼接处要删除clientid 地址。例：http://127.0.0.1:18083/api/v4/clients/clientid_test
        String url = String.format(ConstantConfig.MQTT_DASHBOARD_URL_STR, ConstantConfig.getServerConfig().getProperty(ConstantConfig.MQTT_DASHBOARD_URL).trim(), clientid );
        CloseableHttpClient httpClient = HttpClients.createDefault();
        HttpDelete httpDelete = new HttpDelete(url);
        RequestConfig requestConfig = RequestConfig.custom().setConnectTimeout(35000).setConnectionRequestTimeout(35000).setSocketTimeout(60000).build();
        httpDelete.setConfig(requestConfig);
        // 这里emqx web的登录名密码。例：admin:public 
        String authString = ConstantConfig.getServerConfig().getProperty(ConstantConfig.MQTT_DASHBOARD_USER).trim()+":"+ConstantConfig.getServerConfig().getProperty(ConstantConfig.MQTT_DASHBOARD_PASSWORD).trim();
        byte[] authEncBytes = Base64.encodeBase64(authString.getBytes());
        String authStringEnc = new String(authEncBytes);
        httpDelete.setHeader("Authorization", "Basic " + authStringEnc);
        httpDelete.setHeader("Content-type", "application/json");
        httpDelete.setHeader("DataEncoding", "UTF-8");
        CloseableHttpResponse httpResponse = null;
        try {
                // 通过http请求进行访问。
                httpResponse = httpClient.execute(httpDelete);
                HttpEntity entity = httpResponse.getEntity();
                // 获得删除结果
                String result = EntityUtils.toString(entity);
        } catch (ClientProtocolException e) {
                e.printStackTrace();
                return ResultDTO.getFailure();
        } catch (IOException e) {
                e.printStackTrace();
                return ResultDTO.getFailure();
        } finally {
                if (httpResponse != null) {
                        try {
                                httpResponse.close();
                        } catch (IOException e) {
                                e.printStackTrace();
                        }
                }
                if (null != httpClient) {
                        try {
                                httpClient.close();
                        } catch (IOException e) {
                                e.printStackTrace();
                        }
                }
        }
        
        return ResultDTO.getSuccess();
    }