HttpClient高级进阶-HttpAsyncClient
简述
本文介绍Apache HttpAsyncClient的最常见用例，从基本用法到如何设置代理，如何使用SSL证书以及最后如何使用异步客户端进行身份验证。
简单Demo
首先，让我们看一下如何在一个简单的例子中使用HttpAsyncClient，发送一个GET请求：
@Test
public void test() throws Exception {
CloseableHttpAsyncClient client = HttpAsyncClients.createDefault();
client.start();
HttpGet request = new HttpGet("http://localhost:8080");
Future future = client.execute(request, null);
HttpResponse response = future.get();
assertThat(response.getStatusLine().getStatusCode(), equalTo(200));
client.close();
}
注意我们在使用之前需要启动
HttpAsyncClients ;
没有它，我们会得到以下异常：java.lang.IllegalStateException: Request cannot be executed;
I/O reactor status: INACTIVE
at o.a.h.u.Asserts.check(Asserts.java:46)
at o.a.h.i.n.c.CloseableHttpAsyncClientBase.
ensureRunning(CloseableHttpAsyncClientBase.java:90)
使用HttpAsyncClient进行多线程处理 现在，让我们看看如何使用HttpAsyncClient同时执行多个请求。
在以下示例中，我们使用HttpAsyncClient和PoolingNHttpClientConnectionManager向三个不同的主机发送三个GET请求：
@Test
public void test() throws Exception {
ConnectingIOReactor ioReactor = new DefaultConnectingIOReactor();
PoolingNHttpClientConnectionManager cm =
new PoolingNHttpClientConnectionManager(ioReactor);
CloseableHttpAsyncClient client =
HttpAsyncClients.custom().setConnectionManager(cm).build();
client.start();
String[] toGet = {
"192.168.0.101:8080",
"192.168.0.102:8080",
"192.168.0.103:8080"
};
GetThread[] threads = new GetThread[toGet.length];
for (int i = 0;
i < threads.length;
i++) {
HttpGet request = new HttpGet(toGet[i]);
threads[i] = new GetThread(client, request);
}
for (GetThread thread : threads) {
thread.start();
}
for (GetThread thread : threads) {
thread.join();
}
}
以下是我们的GetThread实现来处理响应：
static class GetThread extends Thread {
private CloseableHttpAsyncClient client;
private HttpContext context;
private HttpGet request;
public GetThread(CloseableHttpAsyncClient client,HttpGet req){
this.client = client;
context = HttpClientContext.create();
this.request = req;
}
@Override
public void run() {
try {
Future future = client.execute(request, context, null);
HttpResponse response = future.get();
assertThat(response.getStatusLine().getStatusCode(), equalTo(200));
} catch (Exception ex) {
System.out.println(ex.getLocalizedMessage());
}
}
}
使用HttpAsyncClient的代理 接下来，让我们来看看如何设置和使用代理服务器与HttpAsyncClient。
在以下示例中，我们通过代理发送HTTP GET请求：
@Test
public void test() throws Exception {
CloseableHttpAsyncClient client = HttpAsyncClients.createDefault();
client.start();
HttpHost proxy = new HttpHost("74.50.126.248", 3127);
RequestConfig config = RequestConfig.custom().setProxy(proxy).build();
HttpGet request = new HttpGet("http://192.168.0.101");
request.setConfig(config);
Future future = client.execute(request, null);
HttpResponse response = future.get();
assertThat(response.getStatusLine().getStatusCode(), equalTo(200));
client.close();
}
使用HttpAsyncClient的SSL证书 现在，让我们来看看如何使用SSL证书与HttpAsyncClient。
在以下示例中， 我们将HttpAsyncClient配置为接受所有证书：
@Test
public void test() throws Exception {
TrustStrategy acceptingTrustStrategy = new TrustStrategy() {
public boolean isTrusted(X509Certificate[] certificate,String authType) {
return true;
}
};
SSLContext sslContext = SSLContexts.custom()
.loadTrustMaterial(null, acceptingTrustStrategy).build();
CloseableHttpAsyncClient client = HttpAsyncClients.custom()
.setSSLHostnameVerifier(SSLConnectionSocketFactory.ALLOW_ALL_HOSTNAME_VERIFIER)
.setSSLContext(sslContext).build();
client.start();
HttpGet request = new HttpGet("");
Future future = client.execute(request, null);
HttpResponse response = future.get();
assertThat(response.getStatusLine().getStatusCode(), equalTo(200));
client.close();
}使用HttpAsyncClient的Cookie 接下来，让我们看看如何在HttpAsyncClient中使用cookie 。
在以下示例中，我们在发送请求之前设置cookie值：
@Test
public void test() throws Exception {
BasicCookieStore cookieStore = new BasicCookieStore();
BasicClientCookie cookie = new BasicClientCookie("JSESSIONID", "1234");
cookie.setDomain(".william.com");
cookie.setPath("/");
cookieStore.addCookie(cookie);
CloseableHttpAsyncClient client = HttpAsyncClients.custom().build();
client.start();
HttpGet request = new HttpGet("http://localhost:8080");
HttpContext localContext = new BasicHttpContext();
localContext.setAttribute(HttpClientContext.COOKIE_STORE, cookieStore);
Future future = client.execute(request, localContext, null);
HttpResponse response = future.get();
assertThat(response.getStatusLine().getStatusCode(), equalTo(200));
client.close();
}
使用HttpAsyncClient进行身份验证 接下来，让我们看看如何使用HttpAsyncClient进行身份验证。
在以下示例中，我们使用CredentialsProvider通过基本身份验证访问主机：
@Test
public void test() throws Exception {
CredentialsProvider provider = new BasicCredentialsProvider();
UsernamePasswordCredentials creds = new UsernamePasswordCredentials("user", "pass");
provider.setCredentials(AuthScope.ANY, creds);
CloseableHttpAsyncClient client =
HttpAsyncClients.custom().setDefaultCredentialsProvider(provider).build();
client.start();
HttpGet request = new HttpGet("http://localhost:8080");
Future future = client.execute(request, null);
HttpResponse response = future.get();
assertThat(response.getStatusLine().getStatusCode(), equalTo(200));
client.close();
}
结论 【HttpClient高级进阶-HttpAsyncClient】本文介绍的内容希望你对HttpAsyncClient有深刻的了解
推荐阅读
- 唐嫣可真会穿，西装搭牛仔裤都能穿出高级感，一双大长腿太抢镜
- 推荐系统论文进阶|CTR预估 论文精读(十一)--Deep Interest Evolution Network(DIEN)
- 鹿鸣高级营养老师徐老师分享应该注意的6种食物
- Java基础-高级特性-枚举实现状态机
- HTTP高级（Cookie，Session|HTTP高级（Cookie，Session ，LocalStorage ）
- 普通人进阶的三个过程-很多人都知道，但却本末倒置
- 易效能进阶课程笔记29
- 程序员|【高级Java架构师系统学习】毕业一年萌新的Java大厂面经，最新整理
- Kotlin泛型的高级特性（六）
- Swift高级应用|Swift高级应用 -01