傳送http請求可以寫成一個工具類，HttpClient可以使用連線池建立，這樣的好處是我們可以自己定義一些配置，比如請求超時時間，最大連線數等等。

public class HttpUtil {
    private static CloseableHttpClient httpClient;
    private static RequestConfig requestConfig = RequestConfig.custom()
            .setSocketTimeout(5000)
            .setConnectTimeout(5000)
            .setConnectionRequestTimeout(5000
 
)
            .build();

    static {
        PoolingHttpClientConnectionManager connManager = new PoolingHttpClientConnectionManager();
        connManager.setMaxTotal(300);
        connManager.setDefaultMaxPerRoute(300);
        httpClient = HttpClients.custom().setConnectionManager(connManager).build();
    }

    // get請求
 

    public static String get(String url) throws IOException {
        HttpGet httpget = new HttpGet(url);
        httpget.setConfig(requestConfig);
        try (CloseableHttpResponse response = httpClient.execute(httpget)) {
            return EntityUtils.toString(response.getEntity(), StandardCharsets.UTF_8);
        }
    }

    // post請求
 

    public static String post(String url, String json) throws IOException {
        HttpEntity entity = new StringEntity(json, ContentType.APPLICATION_JSON);
        HttpPost httpPost = new HttpPost(url);
        httpPost.setEntity(entity);
        httpPost.setConfig(requestConfig);
        try (CloseableHttpResponse response = httpClient.execute(httpPost)) {
            return EntityUtils.toString(response.getEntity(), StandardCharsets.UTF_8);
        }
    }

如果url後面需要接引數，那麼可以寫個方法將引數拼在url後面即可。