Apache HttpClient 5 使用詳細教程
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超文本傳輸協議（HTTP）可能是當今互聯網上最重要的協議之一，Web 服務、微服務以及支持網絡的各種設備上的服務幾乎都是 HTTP 協議，HTTP 協議已經從 Web 瀏覽器走向了更廣泛的使用場景。
雖然 java.net 包已經提供了 HTTP 訪問資源的基本功能，但是它不夠靈活，而且不能隨心所欲的進行自定義。Apache HttpClient 5 是一個開源的 HTTP 工具包，可以支持最新 HTTP 協議標準，且有豐富的 API 和強大的擴展特性，可以用於構建任何需要進行 HTTP 協議處理的應用程序。
這篇文章介紹 Apache HttpClient 5 中最爲常見的一些用法，通過這篇文章可以快速的入門使用 HttpClient 5，主要內容包括 HttpClient 5 的 Get 請求、Post 請求、如何攜帶參數、JSON 參數、設置超時、異步請求、操作 Cookie、表單登錄、基本認證、Digest 認證以及自定義 HTTP 請求攔截器等。
HttpClient 5 依賴
HttpClient 5 Maven 依賴
<!-- https://mvnrepository.com/artifact/org.apache.httpcomponents.client5/httpclient5 -->
<dependency>
<groupId>org.apache.httpcomponents.client5</groupId>
<artifactId>httpclient5</artifactId>
<version>5.1.3</version>
</dependency>
<!-- https://mvnrepository.com/artifact/org.apache.httpcomponents.client5/httpclient5-fluent -->
<dependency>
<groupId>org.apache.httpcomponents.client5</groupId>
<artifactId>httpclient5-fluent</artifactId>
<version>5.1.3</version>
</dependency>HttpClient 5 Gradle 依賴
implementation 'org.apache.httpcomponents.client5:httpclient5:5.1.3'
implementation 'org.apache.httpcomponents.client5:httpclient5-fluent:5.1.3'HttpClient 5 GET 請求
package com.wdbyte.httpclient;
import java.io.IOException;
import org.apache.hc.client5.http.classic.methods.HttpGet;
import org.apache.hc.client5.http.impl.classic.CloseableHttpClient;
import org.apache.hc.client5.http.impl.classic.CloseableHttpResponse;
import org.apache.hc.client5.http.impl.classic.HttpClients;
import org.apache.hc.core5.http.HttpEntity;
import org.apache.hc.core5.http.ParseException;
import org.apache.hc.core5.http.io.entity.EntityUtils;
/**
* @author https://www.wdbyte.com
*/
public class HttpClient5Get {
public static void main(String[] args) {
String result = get("http://httpbin.org/get");
System.out.println(result);
}
public static String get(String url) {
String resultContent = null;
HttpGet httpGet = new HttpGet(url);
try (CloseableHttpClient httpclient = HttpClients.createDefault()) {
try (CloseableHttpResponse response = httpclient.execute(httpGet)) {
// 獲取狀態碼
System.out.println(response.getVersion()); // HTTP/1.1
System.out.println(response.getCode()); // 200
System.out.println(response.getReasonPhrase()); // OK
HttpEntity entity = response.getEntity();
// 獲取響應信息
resultContent = EntityUtils.toString(entity);
}
} catch (IOException | ParseException e) {
e.printStackTrace();
}
return resultContent;
}
}響應信息：
HTTP/1.1
200
OK
{
"args": {},
"headers": {
"Accept-Encoding": "gzip, x-gzip, deflate",
"Host": "httpbin.org",
"User-Agent": "Apache-HttpClient/5.1.3 (Java/17)",
"X-Amzn-Trace-Id": "Root=1-62bb1891-5ab5e5376ed960471bf32f17"
},
"origin": "47.251.4.198",
"url": "http://httpbin.org/get"
}HttpClient 5 Fluent GET
使用 Apache HttpClient 5 提供的 Fluent API 可以更便捷的發起 GET 請求，但是可操作的地方較少。
依賴：
<!-- https://mvnrepository.com/artifact/org.apache.httpcomponents.client5/httpclient5-fluent -->
<dependency>
<groupId>org.apache.httpcomponents.client5</groupId>
<artifactId>httpclient5-fluent</artifactId>
<version>5.1.3</version>
</dependency>示例：
package com.wdbyte.httpclient;
import java.io.IOException;
import org.apache.hc.client5.http.fluent.Request;
import org.apache.hc.client5.http.fluent.Response;
/**
* @author https://www.wdbyte.com
*/
public class HttpClient5GetFluent {
public static void main(String[] args) {
System.out.println(get("http://httpbin.org/get"));
}
public static String get(String url) {
String result = null;
try {
Response response = Request.get(url).execute();
result = response.returnContent().asString();
} catch (IOException e) {
e.printStackTrace();
}
return result;
}
}輸出信息：
{
"args": {},
"headers": {
"Accept-Encoding": "gzip, x-gzip, deflate",
"Host": "httpbin.org",
"User-Agent": "Apache-HttpClient/5.1.3 (Java/17)",
"X-Amzn-Trace-Id": "Root=1-62bb190e-1ba46a92645843a04c55da32"
},
"origin": "47.251.4.198",
"url": "http://httpbin.org/get"
}HttpClient5 GET 請求參數
使用 URIBuilder 的 addParameters() 方法來構建 GET 請求的參數。
package com.wdbyte.httpclient;
import java.io.IOException;
import java.net.URI;
import java.net.URISyntaxException;
import java.util.ArrayList;
import java.util.List;
import org.apache.hc.client5.http.classic.methods.HttpGet;
import org.apache.hc.client5.http.impl.classic.CloseableHttpClient;
import org.apache.hc.client5.http.impl.classic.CloseableHttpResponse;
import org.apache.hc.client5.http.impl.classic.HttpClients;
import org.apache.hc.core5.http.HttpEntity;
import org.apache.hc.core5.http.NameValuePair;
import org.apache.hc.core5.http.ParseException;
import org.apache.hc.core5.http.io.entity.EntityUtils;
import org.apache.hc.core5.http.message.BasicNameValuePair;
import org.apache.hc.core5.net.URIBuilder;
/**
* @author https://www.wdbyte.com
*/
public class HttpClient5GetParams {
public static void main(String[] args) {
String result = get("http://httpbin.org/get");
System.out.println(result);
}
public static String get(String url) {
String resultContent = null;
HttpGet httpGet = new HttpGet(url);
// 表單參數
List<NameValuePair> nvps = new ArrayList<>();
// GET 請求參數
nvps.add(new BasicNameValuePair("username", "wdbyte.com"));
nvps.add(new BasicNameValuePair("password", "secret"));
// 增加到請求 URL 中
try {
URI uri = new URIBuilder(new URI(url))
.addParameters(nvps)
.build();
httpGet.setUri(uri);
} catch (URISyntaxException e) {
throw new RuntimeException(e);
}
try (CloseableHttpClient httpclient = HttpClients.createDefault()) {
try (CloseableHttpResponse response = httpclient.execute(httpGet)) {
// 獲取狀態碼
System.out.println(response.getVersion()); // HTTP/1.1
System.out.println(response.getCode()); // 200
System.out.println(response.getReasonPhrase()); // OK
HttpEntity entity = response.getEntity();
// 獲取響應信息
resultContent = EntityUtils.toString(entity);
}
} catch (IOException | ParseException e) {
e.printStackTrace();
}
return resultContent;
}
}輸出信息：
{
"args": {
"password": "secret",
"username": "wdbyte.com"
},
"headers": {
"Accept-Encoding": "gzip, x-gzip, deflate",
"Host": "httpbin.org",
"User-Agent": "Apache-HttpClient/5.1.3 (Java/1.8.0_151)",
"X-Amzn-Trace-Id": "Root=1-62ecc660-69d58a226aefb1b6226541ec"
},
"origin": "42.120.75.185",
"url": "http://httpbin.org/get?user
}下面是通過抓包得到的請求響應信息格式：
// 請求信息
GET /get?username=wdbyte.com&password=secret HTTP/1.1
Accept-Encoding: gzip, x-gzip, deflate
Host: httpbin.org
Connection: keep-alive
User-Agent: Apache-HttpClient/5.1.3 (Java/1.8.0_151)
// 響應信息
HTTP/1.1 200 OK
Date: Fri, 05 Aug 2022 07:27:30 GMT
Content-Type: application/json
Content-Length: 405
Connection: keep-alive
Server: gunicorn/19.9.0
Access-Control-Allow-Origin: *
Access-Control-Allow-Credentials: true
{
"args": {
"password": "secret",
"username": "wdbyte.com"
},
"headers": {
"Accept-Encoding": "gzip, x-gzip, deflate",
"Host": "httpbin.org",
"User-Agent": "Apache-HttpClient/5.1.3 (Java/1.8.0_151)",
"X-Amzn-Trace-Id": "Root=1-62ecc660-69d58a226aefb1b6226541ec"
},
"origin": "42.120.75.185",
"url": "http://httpbin.org/get?user
}HttpClient 5 POST 請求
下面演示發起一個 POST 請求，並攜帶表單參數。
參數：username=wdbyte.com&password=secret
package com.wdbyte.httpclient;
import java.io.IOException;
import java.util.ArrayList;
import java.util.List;
import org.apache.hc.client5.http.classic.methods.HttpPost;
import org.apache.hc.client5.http.entity.UrlEncodedFormEntity;
import org.apache.hc.client5.http.impl.classic.CloseableHttpClient;
import org.apache.hc.client5.http.impl.classic.CloseableHttpResponse;
import org.apache.hc.client5.http.impl.classic.HttpClients;
import org.apache.hc.core5.http.HttpEntity;
import org.apache.hc.core5.http.NameValuePair;
import org.apache.hc.core5.http.ParseException;
import org.apache.hc.core5.http.io.entity.EntityUtils;
import org.apache.hc.core5.http.message.BasicNameValuePair;
/**
* @author https://www.wdbyte.com
*/
public class HttpClient5Post {
public static void main(String[] args) {
String result = post("http://httpbin.org/post");
System.out.println(result);
}
public static String post(String url) {
String result = null;
HttpPost httpPost = new HttpPost(url);
// 表單參數
List<NameValuePair> nvps = new ArrayList<>();
// POST 請求參數
nvps.add(new BasicNameValuePair("username", "wdbyte.com"));
nvps.add(new BasicNameValuePair("password", "secret"));
httpPost.setEntity(new UrlEncodedFormEntity(nvps));
try (CloseableHttpClient httpclient = HttpClients.createDefault()) {
try (CloseableHttpResponse response = httpclient.execute(httpPost)) {
System.out.println(response.getVersion()); // HTTP/1.1
System.out.println(response.getCode()); // 200
System.out.println(response.getReasonPhrase()); // OK
HttpEntity entity = response.getEntity();
// 獲取響應信息
result = EntityUtils.toString(entity);
// 確保流被完全消費
EntityUtils.consume(entity);
}
} catch (IOException | ParseException e) {
e.printStackTrace();
}
return result;
}
}輸出信息：
HTTP/1.1
200
OK
{
"args": {},
"data": "",
"files": {},
"form": {
"password": "secret",
"username": "wdbyte.com"
},
"headers": {
"Accept-Encoding": "gzip, x-gzip, deflate",
"Content-Length": "35",
"Content-Type": "application/x-www-form-urlencoded; charset=ISO-8859-1",
"Host": "httpbin.org",
"User-Agent": "Apache-HttpClient/5.1.3 (Java/17)",
"X-Amzn-Trace-Id": "Root=1-62bb1ac8-489b2100728c81d70797a482"
},
"json": null,
"origin": "183.128.136.89",
"url": "http://httpbin.org/post"
}下面是通過 Wireshark 抓包得到的請求信息：
POST /post HTTP/1.1
Accept-Encoding: gzip, x-gzip, deflate
Content-Length: 35
Content-Type: application/x-www-form-urlencoded; charset=ISO-8859-1
Host: httpbin.org
Connection: keep-alive
User-Agent: Apache-HttpClient/5.1.3 (Java/17)
username=wdbyte.com&password=secretHttpClient 5 Fluent POST
使用 Apache HttpClient 5 提供的 Fluent API 可以更便捷的發起 POST 請求，但是可操作的地方較少。
一樣發送一個簡單的表單參數：username=wdbyte.com&password=secret
package com.wdbyte.httpclient;
import java.io.IOException;
import org.apache.hc.client5.http.fluent.Request;
import org.apache.hc.core5.http.message.BasicNameValuePair;
/**
* @author https://www.wdbyte.com
*/
public class HttpClient5PostFluent {
public static void main(String[] args) {
String result = post("http://httpbin.org/post");
System.out.println(result);
}
public static String post(String url) {
String result = null;
Request request = Request.post(url);
// POST 請求參數
request.bodyForm(
new BasicNameValuePair("username", "wdbyte.com"),
new BasicNameValuePair("password", "secret"));
try {
result = request.execute().returnContent().asString();
} catch (IOException e) {
e.printStackTrace();
}
return result;
}
}輸出信息：
{
"args": {},
"data": "",
"files": {},
"form": {
"password": "secret",
"username": "wdbyte.com"
},
"headers": {
"Accept-Encoding": "gzip, x-gzip, deflate",
"Content-Length": "35",
"Content-Type": "application/x-www-form-urlencoded; charset=ISO-8859-1",
"Host": "httpbin.org",
"User-Agent": "Apache-HttpClient/5.1.3 (Java/17)",
"X-Amzn-Trace-Id": "Root=1-62bb1c8a-7aee8c004f06919f31a2b533"
},
"json": null,
"origin": "183.128.136.89",
"url": "http://httpbin.org/post"
}HttpClient5 POST JSON 參數
使用 StringEntity 類存入 JSON 參數。
package com.wdbyte.httpclient;
import java.io.IOException;
import org.apache.hc.client5.http.classic.methods.HttpPost;
import org.apache.hc.client5.http.impl.classic.CloseableHttpClient;
import org.apache.hc.client5.http.impl.classic.CloseableHttpResponse;
import org.apache.hc.client5.http.impl.classic.HttpClients;
import org.apache.hc.core5.http.ParseException;
import org.apache.hc.core5.http.io.entity.EntityUtils;
import org.apache.hc.core5.http.io.entity.StringEntity;
/**
* @author https://www.wdbyte.com
*/
public class HttpClient5PostWithJson {
public static void main(String[] args) {
String json = "{"
+ " \"password\": \"secret\","
+ " \"username\": \"wdbyte.com\""
+ "}";
String result = post("http://httpbin.org/post", json);
System.out.println(result);
}
public static String post(String url, String jsonBody) {
String result = null;
HttpPost httpPost = new HttpPost(url);
httpPost.setEntity(new StringEntity(jsonBody, ContentType.APPLICATION_JSON));
try (CloseableHttpClient httpclient = HttpClients.createDefault()) {
try (CloseableHttpResponse response = httpclient.execute(httpPost)) {
// 獲取響應信息
result = EntityUtils.toString(response.getEntity());
}
} catch (IOException | ParseException e) {
e.printStackTrace();
}
return result;
}
}輸出信息：
{
"args": {},
"data": "{ \"password\": \"secret\", \"username\": \"wdbyte.com\"}",
"files": {},
"form": {},
"headers": {
"Accept-Encoding": "gzip, x-gzip, deflate",
"Content-Length": "55",
"Content-Type": "text/plain; charset=ISO-8859-1",
"Host": "httpbin.org",
"User-Agent": "Apache-HttpClient/5.1.3 (Java/17)",
"X-Amzn-Trace-Id": "Root=1-62bb1dbb-5a963c1d798b06be3ee1a15e"
},
"json": {
"password": "secret",
"username": "wdbyte.com"
},
"origin": "183.128.136.89",
"url": "http://httpbin.org/post"
}下面是通過 Wireshark 抓包得到的請求響應信息：
// 請求信息
POST /post HTTP/1.1
Accept-Encoding: gzip, x-gzip, deflate
Content-Length: 55
Content-Type: application/json; charset=UTF-8
Host: httpbin.org
Connection: keep-alive
User-Agent: Apache-HttpClient/5.1.3 (Java/17)
{ "password": "secret", "username": "wdbyte.com"}
// 響應信息
HTTP/1.1 200 OK
Date: Tue, 28 Jun 2022 15:30:17 GMT
Content-Type: application/json
Content-Length: 573
Connection: keep-alive
Server: gunicorn/19.9.0
Access-Control-Allow-Origin: *
Access-Control-Allow-Credentials: true
{
"args": {},
"data": "{ \"password\": \"secret\", \"username\": \"wdbyte.com\"}",
"files": {},
"form": {},
"headers": {
"Accept-Encoding": "gzip, x-gzip, deflate",
"Content-Length": "55",
"Content-Type": "application/json; charset=UTF-8",
"Host": "httpbin.org",
"User-Agent": "Apache-HttpClient/5.1.3 (Java/17)",
"X-Amzn-Trace-Id": "Root=1-62bb1e89-64db55730a0361c720232ccd"
},
"json": {
"password": "secret",
"username": "wdbyte.com"
},
"origin": "183.128.136.89",
"url": "http://httpbin.org/post"
}HttpClient 5 設置超時
使用 RequestConfig 對象來配置超時時間。
package com.wdbyte.httpclient;
import java.io.IOException;
import org.apache.hc.client5.http.classic.methods.HttpGet;
import org.apache.hc.client5.http.config.RequestConfig;
import org.apache.hc.client5.http.impl.classic.CloseableHttpClient;
import org.apache.hc.client5.http.impl.classic.CloseableHttpResponse;
import org.apache.hc.client5.http.impl.classic.HttpClients;
import org.apache.hc.core5.http.HttpEntity;
import org.apache.hc.core5.http.ParseException;
import org.apache.hc.core5.http.io.entity.EntityUtils;
import org.apache.hc.core5.util.Timeout;
/**
* @author https://www.wdbyte.com
*/
public class HttpClient5GetWithTimeout {
public static void main(String[] args) {
String result = get("http://httpbin.org/get");
System.out.println(result);
}
public static String get(String url) {
String resultContent = null;
// 設置超時時間
RequestConfig config = RequestConfig.custom()
.setConnectTimeout(Timeout.ofMilliseconds(5000L))
.setConnectionRequestTimeout(Timeout.ofMilliseconds(5000L))
.setResponseTimeout(Timeout.ofMilliseconds(5000L))
.build();
// 請求級別的超時
HttpGet httpGet = new HttpGet(url);
//httpGet.setConfig(config);
//try (CloseableHttpClient httpclient = HttpClients.createDefault()) {
// 客戶端級別的超時
try (CloseableHttpClient httpclient = HttpClients.custom().setDefaultRequestConfig(config).build()) {
try (CloseableHttpResponse response = httpclient.execute(httpGet)) {
// 獲取狀態碼
System.out.println(response.getVersion()); // HTTP/1.1
System.out.println(response.getCode()); // 200
System.out.println(response.getReasonPhrase()); // OK
HttpEntity entity = response.getEntity();
// 獲取響應信息
resultContent = EntityUtils.toString(entity);
}
} catch (IOException | ParseException e) {
e.printStackTrace();
}
return resultContent;
}
}HttpClient 5 異步請求
下面演示三種 HttpClient 5 異步請求方式。
package com.wdbyte.httpclient;
import java.io.IOException;
import java.nio.CharBuffer;
import java.util.concurrent.CountDownLatch;
import java.util.concurrent.ExecutionException;
import java.util.concurrent.Future;
import org.apache.hc.client5.http.async.methods.AbstractCharResponseConsumer;
import org.apache.hc.client5.http.async.methods.SimpleHttpRequest;
import org.apache.hc.client5.http.async.methods.SimpleHttpRequests;
import org.apache.hc.client5.http.async.methods.SimpleHttpResponse;
import org.apache.hc.client5.http.impl.async.CloseableHttpAsyncClient;
import org.apache.hc.client5.http.impl.async.HttpAsyncClients;
import org.apache.hc.core5.concurrent.FutureCallback;
import org.apache.hc.core5.http.ContentType;
import org.apache.hc.core5.http.HttpException;
import org.apache.hc.core5.http.HttpResponse;
import org.apache.hc.core5.http.nio.AsyncRequestProducer;
import org.apache.hc.core5.http.nio.support.AsyncRequestBuilder;
/**
* HttpClient 5 異步請求
* @author https://www.wdbyte.com
* @date 2022/06/25
*/
public class HttpClient5Async {
public static void main(String[] args) {
getAsync1("http://httpbin.org/get");
getAsync2("http://httpbin.org/get");
getAsync3("http://httpbin.org/get");
}
/**
* 異步請求
*
* @param url
* @return
*/
public static String getAsync1(String url) {
try (CloseableHttpAsyncClient httpclient = HttpAsyncClients.createDefault()) {
// 開始 http clinet
httpclient.start();
// 執行請求
SimpleHttpRequest request1 = SimpleHttpRequests.get(url);
Future<SimpleHttpResponse> future = httpclient.execute(request1, null);
// 等待直到返回完畢
SimpleHttpResponse response1 = future.get();
System.out.println("getAsync1:" + request1.getRequestUri() + "->" + response1.getCode());
} catch (IOException | ExecutionException | InterruptedException e) {
throw new RuntimeException(e);
}
return null;
}
/**
* 異步請求，根據響應情況回調
*
* @param url
* @return
*/
public static String getAsync2(String url) {
try (CloseableHttpAsyncClient httpclient = HttpAsyncClients.createDefault()) {
// 開始 http clinet
httpclient.start();
// 根據請求響應情況進行回調操作
CountDownLatch latch = new CountDownLatch(1);
SimpleHttpRequest request = SimpleHttpRequests.get(url);
httpclient.execute(request, new FutureCallback<SimpleHttpResponse>() {
@Override
public void completed(SimpleHttpResponse response2) {
latch.countDown();
System.out.println("getAsync2:" + request.getRequestUri() + "->" + response2.getCode());
}
@Override
public void failed(Exception ex) {
latch.countDown();
System.out.println("getAsync2:" + request.getRequestUri() + "->" + ex);
}
@Override
public void cancelled() {
latch.countDown();
System.out.println("getAsync2:" + request.getRequestUri() + " cancelled");
}
});
latch.await();
} catch (IOException | InterruptedException e) {
throw new RuntimeException(e);
}
return null;
}
/**
* 異步請求，對響應流做點什麼
*
* @param url
* @return
*/
public static String getAsync3(String url) {
try (CloseableHttpAsyncClient httpclient = HttpAsyncClients.createDefault()) {
// 開始 http clinet
httpclient.start();
// 根據請求響應情況進行回調操作
SimpleHttpRequest request = SimpleHttpRequests.get(url);
CountDownLatch latch = new CountDownLatch(1);
AsyncRequestProducer producer = AsyncRequestBuilder.get("http://httpbin.org/get").build();
AbstractCharResponseConsumer<HttpResponse> consumer3 = new AbstractCharResponseConsumer<HttpResponse>() {
HttpResponse response;
@Override
protected void start(HttpResponse response, ContentType contentType) throws HttpException, IOException {
System.out.println("getAsync3: 開始響應....");
this.response = response;
}
@Override
protected int capacityIncrement() {
return Integer.MAX_VALUE;
}
@Override
protected void data(CharBuffer data, boolean endOfStream) throws IOException {
System.out.println("getAsync3: 收到數據....");
// Do something useful
}
@Override
protected HttpResponse buildResult() throws IOException {
System.out.println("getAsync3: 接收完畢...");
return response;
}
@Override
public void releaseResources() {
}
};
httpclient.execute(producer, consumer3, new FutureCallback<HttpResponse>() {
@Override
public void completed(HttpResponse response) {
latch.countDown();
System.out.println("getAsync3: "+request.getRequestUri() + "->" + response.getCode());
}
@Override
public void failed(Exception ex) {
latch.countDown();
System.out.println("getAsync3: "+request.getRequestUri() + "->" + ex);
}
@Override
public void cancelled() {
latch.countDown();
System.out.println("getAsync3: "+request.getRequestUri() + " cancelled");
}
});
latch.await();
} catch (IOException | InterruptedException e) {
throw new RuntimeException(e);
}
return null;
}
}輸出結果：
getAsync1:/get->200
getAsync2:/get->200
getAsync3: 開始響應....
getAsync3: 收到數據....
getAsync3: 收到數據....
getAsync3: 收到數據....
getAsync3: 接收完畢...
getAsync3: /get->200HttpClient 5 獲取 Cookie
請求 http://httpbin.org/cookies/set/cookieName/www.wdbyte.com 的響應中會帶有一個 Cookie 信息，其中 name 爲 cookieName，value 爲 www.wdbyte.com，我們以此用作測試。
Postman 請求測試，可以看到響應了 Cookie 信息。
下面編寫 Java 代碼進行請求測試
package com.wdbyte.httpclient;
import java.util.List;
import org.apache.hc.client5.http.classic.methods.HttpGet;
import org.apache.hc.client5.http.cookie.BasicCookieStore;
import org.apache.hc.client5.http.cookie.Cookie;
import org.apache.hc.client5.http.cookie.CookieStore;
import org.apache.hc.client5.http.impl.classic.CloseableHttpClient;
import org.apache.hc.client5.http.impl.classic.CloseableHttpResponse;
import org.apache.hc.client5.http.impl.classic.HttpClients;
import org.apache.hc.client5.http.impl.cookie.BasicClientCookie;
import org.apache.hc.client5.http.protocol.HttpClientContext;
import org.apache.hc.core5.http.io.entity.EntityUtils;
/**
* 這個例子演示了使用本地HTTP上下文填充, 自定義屬性
*/
public class HttpClient5WithCookie {
public static void main(final String[] args) throws Exception {
try (final CloseableHttpClient httpclient = HttpClients.createDefault()) {
// 創建一個本地的 Cookie 存儲
final CookieStore cookieStore = new BasicCookieStore();
// BasicClientCookie clientCookie = new BasicClientCookie("name", "www.wdbyte.com");
// clientCookie.setDomain("http://httpbin.org/cookies");
// 過期時間
// clientCookie.setExpiryDate(new Date());
// 添加到本地 Cookie
// cookieStore.addCookie(clientCookie);
// 創建本地 HTTP 請求上下文 HttpClientContext
final HttpClientContext localContext = HttpClientContext.create();
// 綁定 cookieStore 到 localContext
localContext.setCookieStore(cookieStore);
final HttpGet httpget = new HttpGet("http://httpbin.org/cookies/set/cookieName/www.wdbyte.com");
System.out.println("執行請求 " + httpget.getMethod() + " " + httpget.getUri());
// 獲取 Coolie 信息
try (final CloseableHttpResponse response = httpclient.execute(httpget, localContext)) {
System.out.println("----------------------------------------");
System.out.println(response.getCode() + " " + response.getReasonPhrase());
final List<Cookie> cookies = cookieStore.getCookies();
for (int i = 0; i < cookies.size(); i++) {
System.out.println("Local cookie: " + cookies.get(i));
}
EntityUtils.consume(response.getEntity());
}
}
}
}輸出結果：
執行請求 GET http://httpbin.org/cookies/set/cookieName/www.wdbyte.com
----------------------------------------
200 OK
Local cookie: [name: cookieName; value: www.wdbyte.com; domain: httpbin.org; path: /; expiry: null]HttpClient 5 讀取文件內容請求
準備一個 JSON 內容格式的文件 params.json。
{"name":"www.wdbyte.com"}讀取這個文件作爲請求參數發起請求。
package com.wdbyte.httpclient;
import java.io.File;
import java.io.FileInputStream;
import org.apache.hc.client5.http.classic.methods.HttpPost;
import org.apache.hc.client5.http.impl.classic.CloseableHttpClient;
import org.apache.hc.client5.http.impl.classic.CloseableHttpResponse;
import org.apache.hc.client5.http.impl.classic.HttpClients;
import org.apache.hc.core5.http.ContentType;
import org.apache.hc.core5.http.io.entity.EntityUtils;
import org.apache.hc.core5.http.io.entity.FileEntity;
import org.apache.hc.core5.http.io.entity.InputStreamEntity;
/**
* 加載數據流作爲 POST 請求參數
*/
public class HttpClient5ChunkEncodedPost {
public static void main(final String[] args) throws Exception {
String params = "/Users/darcy/params.json";
try (final CloseableHttpClient httpclient = HttpClients.createDefault()) {
final HttpPost httppost = new HttpPost("http://httpbin.org/post");
final InputStreamEntity reqEntity = new InputStreamEntity(new FileInputStream(params), -1,
ContentType.APPLICATION_JSON);
// 也可以使用 FileEntity 的形式
// FileEntity reqEntity = new FileEntity(new File(params), ContentType.APPLICATION_JSON);
httppost.setEntity(reqEntity);
System.out.println("執行請求 " + httppost.getMethod() + " " + httppost.getUri());
try (final CloseableHttpResponse response = httpclient.execute(httppost)) {
System.out.println("----------------------------------------");
System.out.println(response.getCode() + " " + response.getReasonPhrase());
System.out.println(EntityUtils.toString(response.getEntity()));
}
}
}
}輸出結果：
執行請求 POST http://httpbin.org/post
----------------------------------------
200 OK
{
"args": {},
"data": "{\"name\":\"www.wdbyte.com\"}\n",
"files": {},
"form": {},
"headers": {
"Accept-Encoding": "gzip, x-gzip, deflate",
"Content-Length": "26",
"Content-Type": "application/json; charset=UTF-8",
"Host": "httpbin.org",
"User-Agent": "Apache-HttpClient/5.1.3 (Java/1.8.0_151)",
"X-Amzn-Trace-Id": "Root=1-62ee4d95-1f956d4303cea09c52694c86"
},
"json": {
"name": "www.wdbyte.com"
},
"origin": "42.120.74.238",
"url": "http://httpbin.org/post"
}HttpClient 5 表單登錄
表單登錄可以理解爲發起一個攜帶了認證信息的請求，然後得到響應的 Cookie 的過程。當然這裏不僅僅適用於表單登錄，也可以是簡單的發起一個攜帶了表單信息的請求。
本應該使用 POST 請求發送表單參數測試，但是在 httpbin.org 中沒有對應的接口用於測試，所以這裏換成了 GET 請求
示例代碼：
package com.wdbyte.httpclient;
import java.util.ArrayList;
import java.util.List;
import org.apache.hc.client5.http.classic.methods.HttpGet;
import org.apache.hc.client5.http.cookie.BasicCookieStore;
import org.apache.hc.client5.http.cookie.Cookie;
import org.apache.hc.client5.http.entity.UrlEncodedFormEntity;
import org.apache.hc.client5.http.impl.classic.CloseableHttpClient;
import org.apache.hc.client5.http.impl.classic.CloseableHttpResponse;
import org.apache.hc.client5.http.impl.classic.HttpClients;
import org.apache.hc.core5.http.HttpEntity;
import org.apache.hc.core5.http.NameValuePair;
import org.apache.hc.core5.http.io.entity.EntityUtils;
import org.apache.hc.core5.http.message.BasicNameValuePair;
/**
* 演示基於表單的登錄
*
* @author https://www.wdbyte.com
*/
public class HttpClient5FormLogin {
public static void main(final String[] args) throws Exception {
final BasicCookieStore cookieStore = new BasicCookieStore();
try (final CloseableHttpClient httpclient = HttpClients.custom()
.setDefaultCookieStore(cookieStore)
.build()) {
// 本應該使用 POST 請求發送表單參數，但是在 httpbin.org 中沒有對應的接口用於測試，所以這裏換成了 GET 請求
// HttpPost httpPost = new HttpPost("http://httpbin.org/cookies/set/username/wdbyte.com");
HttpGet httpPost = new HttpGet("http://httpbin.org/cookies/set/username/wdbyte.com");
// POST 表單請求參數
List<NameValuePair> nvps = new ArrayList<>();
nvps.add(new BasicNameValuePair("username", "wdbyte.com"));
nvps.add(new BasicNameValuePair("password", "secret"));
httpPost.setEntity(new UrlEncodedFormEntity(nvps));
try (final CloseableHttpResponse response2 = httpclient.execute(httpPost)) {
final HttpEntity entity = response2.getEntity();
System.out.println("Login form get: " + response2.getCode() + " " + response2.getReasonPhrase());
System.out.println("當前響應信息 "+EntityUtils.toString(entity));;
System.out.println("Post 登錄 Cookie:");
final List<Cookie> cookies = cookieStore.getCookies();
if (cookies.isEmpty()) {
System.out.println("None");
} else {
for (int i = 0; i < cookies.size(); i++) {
System.out.println("- " + cookies.get(i));
}
}
}
}
}
}輸出結果：
Login form get: 200 OK
當前響應信息 {
"cookies": {
"username": "wdbyte.com"
}
}
Post 登錄 Cookie:
- [name: username; value: wdbyte.com; domain: httpbin.org; path: /; expiry: null]HttpClient 5 Basic Authorization
HTTP 基本認證（Basic Authorization）是一種比較簡單的認證實現，主要流程如下
-
1. 請求一個需要進行基本認證的 HTTP 接口，但是沒有攜帶認證信息。
-
2. 此時會響應 401 狀態碼，並在響應 header 中的 WWW-Authenticate 提示需要進行基本認證。
-
3. 用戶把需要提交認證信息進行冒號拼接，然後進行 base64 編碼，再在得到的字符串開頭拼接上 Basic 放入請求頭 Authorization 中。
-
4. 認證成功，響應成功。
你可以通過瀏覽器打開下面這個 URL 進行基本認證測試。
http://httpbin.org/basic-auth/admin/123456
在 Apache HttpClient 5 中的實現方式。
package com.wdbyte.httpclient;
import org.apache.hc.client5.http.auth.AuthScope;
import org.apache.hc.client5.http.auth.UsernamePasswordCredentials;
import org.apache.hc.client5.http.classic.methods.HttpGet;
import org.apache.hc.client5.http.impl.auth.BasicCredentialsProvider;
import org.apache.hc.client5.http.impl.classic.CloseableHttpClient;
import org.apache.hc.client5.http.impl.classic.CloseableHttpResponse;
import org.apache.hc.client5.http.impl.classic.HttpClients;
import org.apache.hc.core5.http.io.entity.EntityUtils;
/**
* 一個簡單的示例,它使用HttpClient執行HTTP請求;
* 一個需要進行用戶身份驗證的目標站點。
*/
public class HttpClient5BasicAuthentication {
public static void main(final String[] args) throws Exception {
final BasicCredentialsProvider credsProvider = new BasicCredentialsProvider();
credsProvider.setCredentials(
new AuthScope("httpbin.org", 80),
new UsernamePasswordCredentials("admin", "123456".toCharArray()));
try (final CloseableHttpClient httpclient = HttpClients.custom()
.setDefaultCredentialsProvider(credsProvider)
.build()) {
final HttpGet httpget = new HttpGet("http://httpbin.org/basic-auth/admin/123456");
System.out.println("執行請求" + httpget.getMethod() + " " + httpget.getUri());
try (final CloseableHttpResponse response = httpclient.execute(httpget)) {
System.out.println("----------------------------------------");
System.out.println(response.getCode() + " " + response.getReasonPhrase());
System.out.println(EntityUtils.toString(response.getEntity()));
}
}
}
}輸出結果：
執行請求GET http://httpbin.org/basic-auth/user/passwd
----------------------------------------
200 OK
{
"authenticated": true,
"user": "user"
}通過抓包可以看到完整的 HTTP 請求響應過程。
// 請求
GET /basic-auth/user/passwd HTTP/1.1
Accept-Encoding: gzip, x-gzip, deflate
Host: httpbin.org
Connection: keep-alive
User-Agent: Apache-HttpClient/5.1.3 (Java/1.8.0_151)
// 響應
HTTP/1.1 401 UNAUTHORIZED
Date: Sat, 06 Aug 2022 08:25:33 GMT
Content-Length: 0
Connection: keep-alive
Server: gunicorn/19.9.0
WWW-Authenticate: Basic realm="Fake Realm"
Access-Control-Allow-Origin: *
Access-Control-Allow-Credentials: true
// 請求
GET /basic-auth/user/passwd HTTP/1.1
Host: httpbin.org
Connection: keep-alive
User-Agent: Apache-HttpClient/5.1.3 (Java/1.8.0_151)
Authorization: Basic dXNlcjpwYXNzd2Q=
// 響應
HTTP/1.1 200 OK
Date: Sat, 06 Aug 2022 08:25:33 GMT
Content-Type: application/json
Content-Length: 47
Connection: keep-alive
Server: gunicorn/19.9.0
Access-Control-Allow-Origin: *
Access-Control-Allow-Credentials: true
{
"authenticated": true,
"user": "user"
}HttpClient 5 Digest Authorization
HTTP Basic Authorization 的缺點顯而易見，密碼通過明文傳輸存在一定的安全風險，Digest Authorization 認證方式解決了明文傳輸的問題，這裏不過多介紹 Digest 的相關內容，通過一個圖簡單的示意 Digest 認證方式的流程。
Digest 認證流程
下面是代碼演示。
package com.wdbyte.httpclient;
import org.apache.hc.client5.http.auth.AuthExchange;
import org.apache.hc.client5.http.auth.AuthScheme;
import org.apache.hc.client5.http.auth.AuthScope;
import org.apache.hc.client5.http.auth.UsernamePasswordCredentials;
import org.apache.hc.client5.http.classic.methods.HttpGet;
import org.apache.hc.client5.http.impl.auth.BasicCredentialsProvider;
import org.apache.hc.client5.http.impl.auth.DigestScheme;
import org.apache.hc.client5.http.impl.classic.CloseableHttpClient;
import org.apache.hc.client5.http.impl.classic.CloseableHttpResponse;
import org.apache.hc.client5.http.impl.classic.HttpClients;
import org.apache.hc.client5.http.protocol.HttpClientContext;
import org.apache.hc.core5.http.HttpHost;
import org.apache.hc.core5.http.io.entity.EntityUtils;
/**
*
* HttpClient如何驗證多個請求的示例
* 使用相同的摘要方案。在初始請求/響應交換之後
* 共享相同執行上下文的所有後續請求都可以重用
* 要向服務器進行身份驗證的最後一個摘要nonce值。
*/
public class HttpClient5PreemptiveDigestAuthentication {
public static void main(final String[] args) throws Exception {
try (final CloseableHttpClient httpclient = HttpClients.createDefault()) {
final HttpHost target = new HttpHost("http", "httpbin.org", 80);
final HttpClientContext localContext = HttpClientContext.create();
final BasicCredentialsProvider credentialsProvider = new BasicCredentialsProvider();
credentialsProvider.setCredentials(
new AuthScope(target),
new UsernamePasswordCredentials("admin", "123456".toCharArray()));
localContext.setCredentialsProvider(credentialsProvider);
final HttpGet httpget = new HttpGet("http://httpbin.org/digest-auth/auth/admin/123456");
System.out.println("執行請求 " + httpget.getMethod() + " " + httpget.getUri());
for (int i = 0; i < 2; i++) {
try (final CloseableHttpResponse response = httpclient.execute(target, httpget, localContext)) {
System.out.println("----------------------------------------");
System.out.println(response.getCode() + " " + response.getReasonPhrase());
EntityUtils.consume(response.getEntity());
final AuthExchange authExchange = localContext.getAuthExchange(target);
if (authExchange != null) {
final AuthScheme authScheme = authExchange.getAuthScheme();
if (authScheme instanceof DigestScheme) {
final DigestScheme digestScheme = (DigestScheme) authScheme;
System.out.println("Nonce: " + digestScheme.getNonce() +
"; count: " + digestScheme.getNounceCount());
}
}
}
}
}
}
}通過抓包工具可以清晰的看到 2 次請求的流程，在最後一次請求中，直接共享了認證信息，沒有再次的重新認證的流程。
// 1. 請求
GET /digest-auth/auth/admin/123456 HTTP/1.1
Accept-Encoding: gzip, x-gzip, deflate
Host: httpbin.org
Connection: keep-alive
User-Agent: Apache-HttpClient/5.1.3 (Java/1.8.0_151)
// 2. 詳情，提示認證，給出參數
HTTP/1.1 401 UNAUTHORIZED
Date: Fri, 12 Aug 2022 07:11:06 GMT
Content-Type: text/html; charset=utf-8
Content-Length: 0
Connection: keep-alive
Server: gunicorn/19.9.0
WWW-Authenticate: Digest realm="me@kennethreitz.com", nonce="8dc5e7974a86a6fcc3cf73230b0c4a93", qop="auth", opaque="64b7f68b386c3acc38131f7472aa2079", algorithm=MD5, stale=FALSE
Set-Cookie: stale_after=never; Path=/
Set-Cookie: fake=fake_value; Path=/
Access-Control-Allow-Origin: *
Access-Control-Allow-Credentials: true
// 3. 參數+密碼 加密後再次請求
GET /digest-auth/auth/admin/123456 HTTP/1.1
Host: httpbin.org
Connection: keep-alive
User-Agent: Apache-HttpClient/5.1.3 (Java/1.8.0_151)
Cookie: fake=fake_value; stale_after=never
Authorization: Digest userme@kennethreitz.com", nonce="8dc5e7974a86a6fcc3cf73230b0c4a93", uri="/digest-auth/auth/admin/123456", response="7c6726f8ac54c1ba28e19c71b2fc7338", qop=auth, nc=00000001, cnonce="2fa61501d47a9d39", algorithm=MD5, opaque="64b7f68b386c3acc38131f7472aa2079"
// 4. 認證成功，響應
HTTP/1.1 200 OK
Date: Fri, 12 Aug 2022 07:11:08 GMT
Content-Type: application/json
Content-Length: 48
Connection: keep-alive
Server: gunicorn/19.9.0
Set-Cookie: fake=fake_value; Path=/
Set-Cookie: stale_after=never; Path=/
Access-Control-Allow-Origin: *
Access-Control-Allow-Credentials: true
{
"authenticated": true,
"user": "admin"
}
// 5. 再次請求，共享了登錄狀態。
GET /digest-auth/auth/admin/123456 HTTP/1.1
Accept-Encoding: gzip, x-gzip, deflate
Host: httpbin.org
Connection: keep-alive
User-Agent: Apache-HttpClient/5.1.3 (Java/1.8.0_151)
Cookie: fake=fake_value; stale_after=never
Authorization: Digest userme@kennethreitz.com", nonce="8dc5e7974a86a6fcc3cf73230b0c4a93", uri="/digest-auth/auth/admin/123456", response="9955ac79f6a51a876a326449447f549d", qop=auth, nc=00000002, cnonce="2fa61501d47a9d39", algorithm=MD5, opaque="64b7f68b386c3acc38131f7472aa2079"
// 5. 認證成功，響應
HTTP/1.1 200 OK
Date: Fri, 12 Aug 2022 07:11:09 GMT
Content-Type: application/json
Content-Length: 48
Connection: keep-alive
Server: gunicorn/19.9.0
Set-Cookie: fake=fake_value; Path=/
Set-Cookie: stale_after=never; Path=/
Access-Control-Allow-Origin: *
Access-Control-Allow-Credentials: true
{
"authenticated": true,
"user": "admin"
}HttpClient 5 攔截器
HttpClient 5 中的攔截器可以對請求過程的各個階段進行攔截處理，通過 HttpClientBuilder 中的關於 Interceptor 的方法可以看到可以進行攔截的節點。
HttpClient5 攔截器
下面編寫一個示例，發起三次請求，每次請求都在請求頭 herader 中增加一個 request-id 參數，然後對 request-id 值爲 2 的請求直接響應 404 結束。
package com.wdbyte.httpclient;
import java.io.IOException;
import java.util.concurrent.atomic.AtomicLong;
import org.apache.hc.client5.http.classic.ExecChain;
import org.apache.hc.client5.http.classic.ExecChain.Scope;
import org.apache.hc.client5.http.classic.ExecChainHandler;
import org.apache.hc.client5.http.classic.methods.HttpGet;
import org.apache.hc.client5.http.impl.ChainElement;
import org.apache.hc.client5.http.impl.classic.CloseableHttpClient;
import org.apache.hc.client5.http.impl.classic.CloseableHttpResponse;
import org.apache.hc.client5.http.impl.classic.HttpClients;
import org.apache.hc.core5.http.ClassicHttpRequest;
import org.apache.hc.core5.http.ClassicHttpResponse;
import org.apache.hc.core5.http.ContentType;
import org.apache.hc.core5.http.EntityDetails;
import org.apache.hc.core5.http.Header;
import org.apache.hc.core5.http.HttpEntity;
import org.apache.hc.core5.http.HttpException;
import org.apache.hc.core5.http.HttpRequest;
import org.apache.hc.core5.http.HttpRequestInterceptor;
import org.apache.hc.core5.http.HttpStatus;
import org.apache.hc.core5.http.io.entity.EntityUtils;
import org.apache.hc.core5.http.io.entity.StringEntity;
import org.apache.hc.core5.http.message.BasicClassicHttpResponse;
import org.apache.hc.core5.http.protocol.HttpContext;
/**
* 展示如何在請求和響應時進行攔截進行自定義處理。
*/
public class HttpClient5Interceptors {
public static void main(final String[] args) throws Exception {
try (final CloseableHttpClient httpclient = HttpClients.custom()
// 添加一個請求 id 到請求 header
.addRequestInterceptorFirst(new HttpRequestInterceptor() {
private final AtomicLong count = new AtomicLong(0);
@Override
public void process(
final HttpRequest request,
final EntityDetails entity,
final HttpContext context) throws HttpException, IOException {
request.setHeader("request-id", Long.toString(count.incrementAndGet()));
}
})
.addExecInterceptorAfter(ChainElement.PROTOCOL.name(), "custom", new ExecChainHandler() {
// 請求 id 爲 2 的，模擬 404 響應，並自定義響應的內容。
@Override
public ClassicHttpResponse execute(
final ClassicHttpRequest request,
final Scope scope,
final ExecChain chain) throws IOException, HttpException {
final Header idHeader = request.getFirstHeader("request-id");
if (idHeader != null && "2".equalsIgnoreCase(idHeader.getValue())) {
final ClassicHttpResponse response = new BasicClassicHttpResponse(HttpStatus.SC_NOT_FOUND,
"Oppsie");
response.setEntity(new StringEntity("bad luck", ContentType.TEXT_PLAIN));
return response;
} else {
return chain.proceed(request, scope);
}
}
})
.build()) {
for (int i = 0; i < 3; i++) {
final HttpGet httpget = new HttpGet("http://httpbin.org/get");
try (final CloseableHttpResponse response = httpclient.execute(httpget)) {
System.out.println("----------------------------------------");
System.out.println("執行請求 " + httpget.getMethod() + " " + httpget.getUri());
System.out.println(response.getCode() + " " + response.getReasonPhrase());
System.out.println(EntityUtils.toString(response.getEntity()));
}
}
}
}
}輸出結果。
----------------------------------------
執行請求 GET http://httpbin.org/get
200 OK
{
"args": {},
"headers": {
"Accept-Encoding": "gzip, x-gzip, deflate",
"Host": "httpbin.org",
"Request-Id": "1",
"User-Agent": "Apache-HttpClient/5.1.3 (Java/1.8.0_151)",
"X-Amzn-Trace-Id": "Root=1-62f615ba-658ccd42182d22534dbba82c"
},
"origin": "42.120.75.221",
"url": "http://httpbin.org/get"
}
----------------------------------------
執行請求 GET http://httpbin.org/get
404 Oppsie
bad luck
----------------------------------------
執行請求 GET http://httpbin.org/get
200 OK
{
"args": {},
"headers": {
"Accept-Encoding": "gzip, x-gzip, deflate",
"Host": "httpbin.org",
"Request-Id": "3",
"User-Agent": "Apache-HttpClient/5.1.3 (Java/1.8.0_151)",
"X-Amzn-Trace-Id": "Root=1-62f615bb-4eb6ba10736ace0e21d0cb8c"
},
"origin": "42.120.75.221",
"url": "http://httpbin.org/get"
}一如既往，文章代碼都存放在 Github.com/niumoo/javaNotes[1].
引用鏈接
[1] Github.com/niumoo/javaNotes: https://github.com/niumoo/JavaNotes/tree/master/tool-java-apache-httpclient
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