# 异步Http2.0客户端 [TOC] > 4.2.0以后移除了异步Http2客户端, 请使用协程Http2客户端 Swoole-1.9.7增加了对`Http2.0`客户端的支持。新增的客户端类名为`Swoole\Http2\Client`，继承自`Swoole\Client`，实现了`Http2.0`客户端协议的完整支持。 Http2.0客户端与Http1.1的最大差别是2.0支持了Stream并发机制，可以同时发起多个`GET`或`POST`请求。最大并发数量受限与服务器端规定的`max_concurrent_streams`设置。 ## 编译安装 需要依赖`nghttp2`库，编译Swoole扩展时需要设置`--enable-http2`、`--enable-openssl`或`--with-openssl-dir`。 ## 使用示例 ~~~ $array = array( "host" => "www.jd.com", "accept-encoding" => "gzip, deflate", 'accept' => 'text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,*/*;q=0.8', 'accept-language' => 'zh-CN,zh;q=0.8,en;q=0.6,zh-TW;q=0.4,ja;q=0.2', 'user-agent' => 'Mozilla/5.0 (X11; Linux x86_64) Chrome/58.0.3026.3 Safari/537.36', ); $client = new Swoole\Http2\Client("www.jd.com", 443, true); $client->setHeaders($array); $client->setCookies(array("a" => "1", "b" => "2")); $client->get("/", function ($o) use($client) { echo "#{$client->sock} hello world 1\n"; echo $o->body; }); $client->post("/", $array, function ($o) use($client) { echo "{$client->sock} hello world 3\n"; echo $o->body; $client->close(); }); Swoole\Event::wait(); ~~~