java中使用Apache HttpClient发送Http请求，并获取返回结果

本是古典何须时尚 2022-05-19 22:54 254阅读 0赞

发送http请求可以写成一个工具类，HttpClient可以使用连接池创建，这样的好处是我们可以自己定义一些配置，比如请求超时时间，最大连接数等等。

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请求
        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请求
        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后面需要接参数，那么可以写个方法将参数拼在url后面即可。