PoolingHttpClientConnectionManager connManager = new PoolingHttpClientConnectionManager(); HttpClient httpClient = HttpClients.custom() .setConnectionManager(connManager) .build(); public class HttpClientSingleton { private static HttpClient instance; private HttpClientSingleton() {} public static synchronized HttpClient getInstance() { if (instance == null) { instance = HttpClientBuilder.create().build(); } return instance; } } RequestConfig requestConfig = RequestConfig.custom() .build(); HttpGet httpGet = new HttpGet("http://example.com"); httpGet.setConfig(requestConfig); HttpPost httpPost = new HttpPost("http://example.com"); httpPost.setHeader("Accept-Encoding", "gzip"); httpPost.setHeader("Cache-Control", "max-age=3600"); EventLoopGroup group = new NioEventLoopGroup(); Bootstrap bootstrap = new Bootstrap(); bootstrap.group(group) .channel(NioSocketChannel.class) .handler(new ChannelInitializer<SocketChannel>() { @Override protected void initChannel(SocketChannel ch) { ch.pipeline().addLast(new HttpObjectCodec()); } }); Channel channel = bootstrap.connect("example.com", 80).sync().channel();