java http请求工具整理

　　处理了http 的get和post的请求，分别支持同步处理，异步处理两种方式下见代码。

@Slf4j
public class HttpUtils {

    /**
     * 同步请求http请求 不推荐
     *
     * @param url
     * @return
     */
    public static byte[] httpGetSync(String url) {
        HttpGet httpGet = new HttpGet(url);
        try (CloseableHttpClient httpclient = HttpClients.createDefault()) {
            CloseableHttpResponse response = httpclient.execute(httpGet);
            if (HttpStatus.SC_OK == response.getStatusLine().getStatusCode()) {
                HttpEntity entity = response.getEntity();
                return Utils.inputStream2Bytes(entity.getContent());
            } else {
                log.error("NetUrls httpGetSync {} url {} ", response.getStatusLine().getStatusCode(), url);
            }
        } catch (IOException exception) {
            log.error("reInitExchangeConfig request exception {}",  exception);
        }
        return null;
    }

    /**
     * 指定执行器的http请求 推荐
     *
     * @param url
     * @param exec
     * @param callback
     */
    public static void httpGet(String url, Executor exec, NetResponse callback) {
        getHttpExec().execute(() -> {
            byte[] bytes = httpGetSync(url);
            exec.execute(() -> {
                callback.response(bytes);
            });
        });
    }

    /**
     * httpPost 请求异步推荐
     *
     * @param url
     * @param data
     * @param contentType
     * @return
     */
    public static byte[] httpPostSync(String url, String data, ContentType contentType) {

        CloseableHttpClient httpClient = HttpClients.createDefault();
        HttpPost httpPost = new HttpPost(url);
        httpPost.setEntity(new StringEntity(data, contentType));

        try (CloseableHttpResponse response = httpClient.execute(httpPost)) {
            if (HttpStatus.SC_OK == response.getStatusLine().getStatusCode()) {
                HttpEntity entity = response.getEntity();
                return Utils.inputStream2Bytes(entity.getContent());
            } else {
                log.warn("HTTP POST Failure {}, {}, {}", url, data, response.getStatusLine().getStatusCode());
            }
        } catch (IOException exception) {
            log.warn("HTTP POST Exception", exception);
        }

        return null;
    }

    /**
     * httpPost 请求异步推荐
     *
     * @param url
     * @param data
     * @param contentType
     * @param exec
     * @param callback
     */
    public static void httpPost(String url, String data, ContentType contentType, Executor exec, NetResponse callback) {
        getHttpExec().execute(() -> {
            byte[] bytes = httpPostSync(url, data, contentType);
            exec.execute(() -> {
                callback.response(bytes);
            });
        });
    }

    /**
     * 不指定执行器的http请求 不推荐
     *
     * @param url
     * @param callback
     */
    public static void httpGetAsync(String url, NetResponse callback) {
        getHttpExec().execute(() -> {
            byte[] bytes = httpGetSync(url);
            callback.response(bytes);
        });
    }

    /**
     * 不指定执行器的http请求 不推荐
     *
     * @param url
     * @param callback
     */
    public static void httpGetAsync(String url, String data, ContentType contentType, NetResponse callback) {
        getHttpExec().execute(() -> {
            byte[] bytes = httpPostSync(url, data, contentType);
            callback.response(bytes);
        });
    }

    private static ExecutorService httpExec;

    private static ExecutorService getHttpExec() {
        if (httpExec == null) {
            synchronized (HttpUtils.class) {
                if (httpExec == null) {
                    httpExec = Executors.newCachedThreadPool();
                }
            }
        }
        return httpExec;
    }

    public interface NetResponse {
        void response(byte[] response);
    }

}