• Apache HttpClient 5 使用详细教程

    HTTP Components Logo

    超文本传输协议（HTTP）可能是当今互联网上最重要的协议之一，Web 服务、微服务以及支持网络的各种设备上的服务几乎都是 HTTP 协议，HTTP 协议已经从 Web 浏览器走向了更广泛的使用场景。

    虽然 java.net 包已经提供了 HTTP 访问资源的基本功能，但是它不够灵活，而且不能随心所欲的进行自定义。Apache HttpClient 5 是一个开源的 HTTP 工具包，可以支持最新 HTTP 协议标准，且有丰富的 API 和强大的扩展特性，可以用于构建任何需要进行 HTTP 协议处理的应用程序。

    这篇文章介绍 Apache HttpClient 5 中最为常见的一些用法，通过这篇文章可以快速的入门使用 HttpClient 5，主要内容包括 HttpClient 5 的 Get 请求、Post 请求、如何携带参数、JSON 参数、设置超时、异步请求、操作 Cookie、表单登录、基本认证、Digest 认证以及自定义 HTTP 请求拦截器等。

    HttpClient 5 依赖

    HttpClient 5 Maven 依赖

    1. <!-- https://mvnrepository.com/artifact/org.apache.httpcomponents.client5/httpclient5 -->
    2. <dependency>
    3.     <groupId>org.apache.httpcomponents.client5</groupId>
    4.     <artifactId>httpclient5</artifactId>
    5.     <version>5.1.3</version>
    6. </dependency>
    7. <!-- https://mvnrepository.com/artifact/org.apache.httpcomponents.client5/httpclient5-fluent -->
    8. <dependency>
    9.     <groupId>org.apache.httpcomponents.client5</groupId>
    10.     <artifactId>httpclient5-fluent</artifactId>
    11.     <version>5.1.3</version>
    12. </dependency>

    HttpClient 5 Gradle 依赖

    1. implementation 'org.apache.httpcomponents.client5:httpclient5:5.1.3'
    2. implementation 'org.apache.httpcomponents.client5:httpclient5-fluent:5.1.3'

    HttpClient 5 GET 请求

    1. package com.wdbyte.httpclient;
    2.  
    3. import java.io.IOException;
    4.  
    5. import org.apache.hc.client5.http.classic.methods.HttpGet;
    6. import org.apache.hc.client5.http.impl.classic.CloseableHttpClient;
    7. import org.apache.hc.client5.http.impl.classic.CloseableHttpResponse;
    8. import org.apache.hc.client5.http.impl.classic.HttpClients;
    9. import org.apache.hc.core5.http.HttpEntity;
    10. import org.apache.hc.core5.http.ParseException;
    11. import org.apache.hc.core5.http.io.entity.EntityUtils;
    12.  
    13. /**
    14.  * @author https://www.wdbyte.com
    15.  */
    16. public class HttpClient5Get {
    17.  
    18.     public static void main(String[] args) {
    19.         String result = get("http://httpbin.org/get");
    20.         System.out.println(result);
    21.     }
    22.  
    23.     public static String get(String url) {
    24.         String resultContent = null;
    25.         HttpGet httpGet = new HttpGet(url);
    26.         try (CloseableHttpClient httpclient = HttpClients.createDefault()) {
    27.             try (CloseableHttpResponse response = httpclient.execute(httpGet)) {
    28.                 // 获取状态码
    29.                 System.out.println(response.getVersion()); // HTTP/1.1
    30.                 System.out.println(response.getCode()); // 200
    31.                 System.out.println(response.getReasonPhrase()); // OK
    32.                 HttpEntity entity = response.getEntity();
    33.                 // 获取响应信息
    34.                 resultContent = EntityUtils.toString(entity);
    35.             }
    36.         } catch (IOException | ParseException e) {
    37.             e.printStackTrace();
    38.         }
    39.         return resultContent;
    40.     }
    41.  
    42. }

    响应信息：

    1. HTTP/1.1
    2. 200
    3. OK
    4. {
    5.   "args": {}, 
    6.   "headers": {
    7.     "Accept-Encoding": "gzip, x-gzip, deflate", 
    8.     "Host": "httpbin.org", 
    9.     "User-Agent": "Apache-HttpClient/5.1.3 (Java/17)", 
    10.     "X-Amzn-Trace-Id": "Root=1-62bb1891-5ab5e5376ed960471bf32f17"
    11.   }, 
    12.   "origin": "47.251.4.198", 
    13.   "url": "http://httpbin.org/get"
    14. }

    HttpClient 5 Fluent GET

    使用 Apache HttpClient 5 提供的 Fluent API 可以更便捷的发起 GET 请求，但是可操作的地方较少。

    依赖：

    1. <!-- https://mvnrepository.com/artifact/org.apache.httpcomponents.client5/httpclient5-fluent -->
    2. <dependency>
    3.     <groupId>org.apache.httpcomponents.client5</groupId>
    4.     <artifactId>httpclient5-fluent</artifactId>
    5.     <version>5.1.3</version>
    6. </dependency>

    示例：

    1. package com.wdbyte.httpclient;
    2.  
    3. import java.io.IOException;
    4.  
    5. import org.apache.hc.client5.http.fluent.Request;
    6. import org.apache.hc.client5.http.fluent.Response;
    7.  
    8. /**
    9. * @author https://www.wdbyte.com
    10.  */
    11. public class HttpClient5GetFluent {
    12.  
    13.     public static void main(String[] args) {
    14.         System.out.println(get("http://httpbin.org/get"));
    15.     }
    16.  
    17.     public static String get(String url) {
    18.         String result = null;
    19.         try {
    20.             Response response = Request.get(url).execute();
    21.             result = response.returnContent().asString();
    22.         } catch (IOException e) {
    23.             e.printStackTrace();
    24.         }
    25.         return result;
    26.     }
    27.  
    28. }

    输出信息：

    1. {
    2.   "args": {}, 
    3.   "headers": {
    4.     "Accept-Encoding": "gzip, x-gzip, deflate", 
    5.     "Host": "httpbin.org", 
    6.     "User-Agent": "Apache-HttpClient/5.1.3 (Java/17)", 
    7.     "X-Amzn-Trace-Id": "Root=1-62bb190e-1ba46a92645843a04c55da32"
    8.   }, 
    9.   "origin": "47.251.4.198", 
    10.   "url": "http://httpbin.org/get"
    11. }

    HttpClient5 GET 请求参数

    使用 URIBuilder 的 addParameters() 方法来构建 GET 请求的参数。

    1. package com.wdbyte.httpclient;
    2.  
    3. import java.io.IOException;
    4. import java.net.URI;
    5. import java.net.URISyntaxException;
    6. import java.util.ArrayList;
    7. import java.util.List;
    8.  
    9. import org.apache.hc.client5.http.classic.methods.HttpGet;
    10. import org.apache.hc.client5.http.impl.classic.CloseableHttpClient;
    11. import org.apache.hc.client5.http.impl.classic.CloseableHttpResponse;
    12. import org.apache.hc.client5.http.impl.classic.HttpClients;
    13. import org.apache.hc.core5.http.HttpEntity;
    14. import org.apache.hc.core5.http.NameValuePair;
    15. import org.apache.hc.core5.http.ParseException;
    16. import org.apache.hc.core5.http.io.entity.EntityUtils;
    17. import org.apache.hc.core5.http.message.BasicNameValuePair;
    18. import org.apache.hc.core5.net.URIBuilder;
    19.  
    20. /**
    21. * @author https://www.wdbyte.com
    22.  */
    23. public class HttpClient5GetParams {
    24.  
    25.     public static void main(String[] args) {
    26.         String result = get("http://httpbin.org/get");
    27.         System.out.println(result);
    28.     }
    29.  
    30.     public static String get(String url) {
    31.         String resultContent = null;
    32.         HttpGet httpGet = new HttpGet(url);
    33.         // 表单参数
    34.         List<NameValuePair> nvps = new ArrayList<>();
    35.         // GET 请求参数
    36.         nvps.add(new BasicNameValuePair("username", "wdbyte.com"));
    37.         nvps.add(new BasicNameValuePair("password", "secret"));
    38.         // 增加到请求 URL 中
    39.         try {
    40.             URI uri = new URIBuilder(new URI(url))
    41.                 .addParameters(nvps)
    42.                 .build();
    43.             httpGet.setUri(uri);
    44.         } catch (URISyntaxException e) {
    45.             throw new RuntimeException(e);
    46.         }
    47.  
    48.         try (CloseableHttpClient httpclient = HttpClients.createDefault()) {
    49.             try (CloseableHttpResponse response = httpclient.execute(httpGet)) {
    50.                 // 获取状态码
    51.                 System.out.println(response.getVersion()); // HTTP/1.1
    52.                 System.out.println(response.getCode()); // 200
    53.                 System.out.println(response.getReasonPhrase()); // OK
    54.                 HttpEntity entity = response.getEntity();
    55.                 // 获取响应信息
    56.                 resultContent = EntityUtils.toString(entity);
    57.             }
    58.         } catch (IOException | ParseException e) {
    59.             e.printStackTrace();
    60.         }
    61.         return resultContent;
    62.     }
    63. }

    输出信息：

    1. {
    2.   "args": {
    3.     "password": "secret", 
    4.     "username": "wdbyte.com"
    5.   }, 
    6.   "headers": {
    7.     "Accept-Encoding": "gzip, x-gzip, deflate", 
    8.     "Host": "httpbin.org", 
    9.     "User-Agent": "Apache-HttpClient/5.1.3 (Java/1.8.0_151)", 
    10.     "X-Amzn-Trace-Id": "Root=1-62ecc660-69d58a226aefb1b6226541ec"
    11.   }, 
    12.   "origin": "42.120.75.185", 
    13.   "url": "http://httpbin.org/get?username=wdbyte.com&password=secret"
    14. }

    下面是通过抓包得到的请求响应信息格式：

    1. // 请求信息
    2. GET /get?username=wdbyte.com&password=secret HTTP/1.1
    3. Accept-Encoding: gzip, x-gzip, deflate
    4. Host: httpbin.org
    5. Connection: keep-alive
    6. User-Agent: Apache-HttpClient/5.1.3 (Java/1.8.0_151)
    7.  
    8. // 响应信息
    9. HTTP/1.1 200 OK
    10. Date: Fri, 05 Aug 2022 07:27:30 GMT
    11. Content-Type: application/json
    12. Content-Length: 405
    13. Connection: keep-alive
    14. Server: gunicorn/19.9.0
    15. Access-Control-Allow-Origin: *
    16. Access-Control-Allow-Credentials: true
    17.  
    18. {
    19.   "args": {
    20.     "password": "secret", 
    21.     "username": "wdbyte.com"
    22.   }, 
    23.   "headers": {
    24.     "Accept-Encoding": "gzip, x-gzip, deflate", 
    25.     "Host": "httpbin.org", 
    26.     "User-Agent": "Apache-HttpClient/5.1.3 (Java/1.8.0_151)", 
    27.     "X-Amzn-Trace-Id": "Root=1-62ecc660-69d58a226aefb1b6226541ec"
    28.   }, 
    29.   "origin": "42.120.75.185", 
    30.   "url": "http://httpbin.org/get?username=wdbyte.com&password=secret"
    31. }

    HttpClient 5 POST 请求

    下面演示发起一个 POST 请求，并携带表单参数。

    参数：username=wdbyte.com&password=secret

    1. package com.wdbyte.httpclient;
    2.  
    3. import java.io.IOException;
    4. import java.util.ArrayList;
    5. import java.util.List;
    6.  
    7. import org.apache.hc.client5.http.classic.methods.HttpPost;
    8. import org.apache.hc.client5.http.entity.UrlEncodedFormEntity;
    9. import org.apache.hc.client5.http.impl.classic.CloseableHttpClient;
    10. import org.apache.hc.client5.http.impl.classic.CloseableHttpResponse;
    11. import org.apache.hc.client5.http.impl.classic.HttpClients;
    12. import org.apache.hc.core5.http.HttpEntity;
    13. import org.apache.hc.core5.http.NameValuePair;
    14. import org.apache.hc.core5.http.ParseException;
    15. import org.apache.hc.core5.http.io.entity.EntityUtils;
    16. import org.apache.hc.core5.http.message.BasicNameValuePair;
    17.  
    18. /**
    19. * @author https://www.wdbyte.com
    20.  */
    21. public class HttpClient5Post {
    22.  
    23.     public static void main(String[] args) {
    24.         String result = post("http://httpbin.org/post");
    25.         System.out.println(result);
    26.     }
    27.     public static String post(String url) {
    28.         String result = null;
    29.         HttpPost httpPost = new HttpPost(url);
    30.         // 表单参数
    31.         List<NameValuePair> nvps = new ArrayList<>();
    32.         // POST 请求参数
    33.         nvps.add(new BasicNameValuePair("username", "wdbyte.com"));
    34.         nvps.add(new BasicNameValuePair("password", "secret"));
    35.         httpPost.setEntity(new UrlEncodedFormEntity(nvps));
    36.         try (CloseableHttpClient httpclient = HttpClients.createDefault()) {
    37.             try (CloseableHttpResponse response = httpclient.execute(httpPost)) {
    38.                 System.out.println(response.getVersion()); // HTTP/1.1
    39.                 System.out.println(response.getCode()); // 200
    40.                 System.out.println(response.getReasonPhrase()); // OK
    41.  
    42.                 HttpEntity entity = response.getEntity();
    43.                 // 获取响应信息
    44.                 result = EntityUtils.toString(entity);
    45.                 // 确保流被完全消费
    46.                 EntityUtils.consume(entity);
    47.             }
    48.         } catch (IOException | ParseException e) {
    49.             e.printStackTrace();
    50.         }
    51.         return result;
    52.     }
    53.  
    54. }

    输出信息：

    1. HTTP/1.1
    2. 200
    3. OK
    4. {
    5.   "args": {}, 
    6.   "data": "", 
    7.   "files": {}, 
    8.   "form": {
    9.     "password": "secret", 
    10.     "username": "wdbyte.com"
    11.   }, 
    12.   "headers": {
    13.     "Accept-Encoding": "gzip, x-gzip, deflate", 
    14.     "Content-Length": "35", 
    15.     "Content-Type": "application/x-www-form-urlencoded; charset=ISO-8859-1", 
    16.     "Host": "httpbin.org", 
    17.     "User-Agent": "Apache-HttpClient/5.1.3 (Java/17)", 
    18.     "X-Amzn-Trace-Id": "Root=1-62bb1ac8-489b2100728c81d70797a482"
    19.   }, 
    20.   "json": null, 
    21.   "origin": "183.128.136.89", 
    22.   "url": "http://httpbin.org/post"
    23. }

    下面是通过 Wireshark 抓包得到的请求信息：

    1. POST /post HTTP/1.1
    2. Accept-Encoding: gzip, x-gzip, deflate
    3. Content-Length: 35
    4. Content-Type: application/x-www-form-urlencoded; charset=ISO-8859-1
    5. Host: httpbin.org
    6. Connection: keep-alive
    7. User-Agent: Apache-HttpClient/5.1.3 (Java/17)
    8.  
    9. username=wdbyte.com&password=secret

    HttpClient 5 Fluent POST

    使用 Apache HttpClient 5 提供的 Fluent API 可以更便捷的发起 POST 请求，但是可操作的地方较少。

    一样发送一个简单的表单参数：username=wdbyte.com&password=secret

    1. package com.wdbyte.httpclient;
    2.  
    3. import java.io.IOException;
    4.  
    5. import org.apache.hc.client5.http.fluent.Request;
    6. import org.apache.hc.core5.http.message.BasicNameValuePair;
    7.  
    8. /**
    9. * @author https://www.wdbyte.com
    10.  */
    11. public class HttpClient5PostFluent {
    12.  
    13.     public static void main(String[] args) {
    14.         String result = post("http://httpbin.org/post");
    15.         System.out.println(result);
    16.     }
    17.  
    18.     public static String post(String url) {
    19.         String result = null;
    20.         Request request = Request.post(url);
    21.         // POST 请求参数
    22.         request.bodyForm(
    23.             new BasicNameValuePair("username", "wdbyte.com"),
    24.             new BasicNameValuePair("password", "secret"));
    25.         try {
    26.             result = request.execute().returnContent().asString();
    27.         } catch (IOException e) {
    28.             e.printStackTrace();
    29.         }
    30.         return result;
    31.     }
    32. }

    输出信息：

    1. {
    2.   "args": {}, 
    3.   "data": "", 
    4.   "files": {}, 
    5.   "form": {
    6.     "password": "secret", 
    7.     "username": "wdbyte.com"
    8.   }, 
    9.   "headers": {
    10.     "Accept-Encoding": "gzip, x-gzip, deflate", 
    11.     "Content-Length": "35", 
    12.     "Content-Type": "application/x-www-form-urlencoded; charset=ISO-8859-1", 
    13.     "Host": "httpbin.org", 
    14.     "User-Agent": "Apache-HttpClient/5.1.3 (Java/17)", 
    15.     "X-Amzn-Trace-Id": "Root=1-62bb1c8a-7aee8c004f06919f31a2b533"
    16.   }, 
    17.   "json": null, 
    18.   "origin": "183.128.136.89", 
    19.   "url": "http://httpbin.org/post"
    20. }

    HttpClient5 POST JSON 参数

    使用 StringEntity 类存入 JSON 参数。

    1. package com.wdbyte.httpclient;
    2.  
    3. import java.io.IOException;
    4.  
    5. import org.apache.hc.client5.http.classic.methods.HttpPost;
    6. import org.apache.hc.client5.http.impl.classic.CloseableHttpClient;
    7. import org.apache.hc.client5.http.impl.classic.CloseableHttpResponse;
    8. import org.apache.hc.client5.http.impl.classic.HttpClients;
    9. import org.apache.hc.core5.http.ParseException;
    10. import org.apache.hc.core5.http.io.entity.EntityUtils;
    11. import org.apache.hc.core5.http.io.entity.StringEntity;
    12.  
    13. /**
    14. * @author https://www.wdbyte.com
    15.  */
    16. public class HttpClient5PostWithJson {
    17.  
    18.     public static void main(String[] args) {
    19.         String json = "{"
    20.             + "    \"password\": \"secret\","
    21.             + "    \"username\": \"wdbyte.com\""
    22.             + "}";
    23.         String result = post("http://httpbin.org/post", json);
    24.         System.out.println(result);
    25.     }
    26.  
    27.     public static String post(String url, String jsonBody) {
    28.         String result = null;
    29.         HttpPost httpPost = new HttpPost(url);
    30.         httpPost.setEntity(new StringEntity(jsonBody, ContentType.APPLICATION_JSON));
    31.       
    32.         try (CloseableHttpClient httpclient = HttpClients.createDefault()) {
    33.             try (CloseableHttpResponse response = httpclient.execute(httpPost)) {
    34.                 // 获取响应信息
    35.                 result = EntityUtils.toString(response.getEntity());
    36.             }
    37.         } catch (IOException | ParseException e) {
    38.             e.printStackTrace();
    39.         }
    40.         return result;
    41.     }
    42.  
    43. }

    输出信息：

    1. {
    2.   "args": {}, 
    3.   "data": "{    \"password\": \"secret\",    \"username\": \"wdbyte.com\"}", 
    4.   "files": {}, 
    5.   "form": {}, 
    6.   "headers": {
    7.     "Accept-Encoding": "gzip, x-gzip, deflate", 
    8.     "Content-Length": "55", 
    9.     "Content-Type": "text/plain; charset=ISO-8859-1", 
    10.     "Host": "httpbin.org", 
    11.     "User-Agent": "Apache-HttpClient/5.1.3 (Java/17)", 
    12.     "X-Amzn-Trace-Id": "Root=1-62bb1dbb-5a963c1d798b06be3ee1a15e"
    13.   }, 
    14.   "json": {
    15.     "password": "secret", 
    16.     "username": "wdbyte.com"
    17.   }, 
    18.   "origin": "183.128.136.89", 
    19.   "url": "http://httpbin.org/post"
    20. }

    下面是通过 Wireshark 抓包得到的请求响应信息：

    1. // 请求信息
    2. POST /post HTTP/1.1
    3. Accept-Encoding: gzip, x-gzip, deflate
    4. Content-Length: 55
    5. Content-Type: application/json; charset=UTF-8
    6. Host: httpbin.org
    7. Connection: keep-alive
    8. User-Agent: Apache-HttpClient/5.1.3 (Java/17)
    9.  
    10. {    "password": "secret",    "username": "wdbyte.com"}
    11.  
    12. // 响应信息
    13. HTTP/1.1 200 OK
    14. Date: Tue, 28 Jun 2022 15:30:17 GMT
    15. Content-Type: application/json
    16. Content-Length: 573
    17. Connection: keep-alive
    18. Server: gunicorn/19.9.0
    19. Access-Control-Allow-Origin: *
    20. Access-Control-Allow-Credentials: true
    21.  
    22. {
    23.   "args": {}, 
    24.   "data": "{    \"password\": \"secret\",    \"username\": \"wdbyte.com\"}", 
    25.   "files": {}, 
    26.   "form": {}, 
    27.   "headers": {
    28.     "Accept-Encoding": "gzip, x-gzip, deflate", 
    29.     "Content-Length": "55", 
    30.     "Content-Type": "application/json; charset=UTF-8", 
    31.     "Host": "httpbin.org", 
    32.     "User-Agent": "Apache-HttpClient/5.1.3 (Java/17)", 
    33.     "X-Amzn-Trace-Id": "Root=1-62bb1e89-64db55730a0361c720232ccd"
    34.   }, 
    35.   "json": {
    36.     "password": "secret", 
    37.     "username": "wdbyte.com"
    38.   }, 
    39.   "origin": "183.128.136.89", 
    40.   "url": "http://httpbin.org/post"
    41. }

    HttpClient 5 设置超时

    使用 RequestConfig 对象来配置超时时间。

    1. package com.wdbyte.httpclient;
    2.  
    3. import java.io.IOException;
    4.  
    5. import org.apache.hc.client5.http.classic.methods.HttpGet;
    6. import org.apache.hc.client5.http.config.RequestConfig;
    7. import org.apache.hc.client5.http.impl.classic.CloseableHttpClient;
    8. import org.apache.hc.client5.http.impl.classic.CloseableHttpResponse;
    9. import org.apache.hc.client5.http.impl.classic.HttpClients;
    10. import org.apache.hc.core5.http.HttpEntity;
    11. import org.apache.hc.core5.http.ParseException;
    12. import org.apache.hc.core5.http.io.entity.EntityUtils;
    13. import org.apache.hc.core5.util.Timeout;
    14.  
    15. /**
    16. * @author https://www.wdbyte.com
    17.  */
    18. public class HttpClient5GetWithTimeout {
    19.  
    20.     public static void main(String[] args) {
    21.         String result = get("http://httpbin.org/get");
    22.         System.out.println(result);
    23.     }
    24.  
    25.     public static String get(String url) {
    26.         String resultContent = null;
    27.         // 设置超时时间
    28.         RequestConfig config = RequestConfig.custom()
    29.             .setConnectTimeout(Timeout.ofMilliseconds(5000L))
    30.             .setConnectionRequestTimeout(Timeout.ofMilliseconds(5000L))
    31.             .setResponseTimeout(Timeout.ofMilliseconds(5000L))
    32.             .build();
    33.         // 请求级别的超时
    34.         HttpGet httpGet = new HttpGet(url);
    35.         //httpGet.setConfig(config);
    36.         //try (CloseableHttpClient httpclient = HttpClients.createDefault()) {
    37.         // 客户端级别的超时
    38.         try (CloseableHttpClient httpclient = HttpClients.custom().setDefaultRequestConfig(config).build()) {
    39.             try (CloseableHttpResponse response = httpclient.execute(httpGet)) {
    40.                 // 获取状态码
    41.                 System.out.println(response.getVersion()); // HTTP/1.1
    42.                 System.out.println(response.getCode()); // 200
    43.                 System.out.println(response.getReasonPhrase()); // OK
    44.                 HttpEntity entity = response.getEntity();
    45.                 // 获取响应信息
    46.                 resultContent = EntityUtils.toString(entity);
    47.             }
    48.         } catch (IOException | ParseException e) {
    49.             e.printStackTrace();
    50.         }
    51.         return resultContent;
    52.     }
    53.  
    54. }

    HttpClient 5 异步请求

    下面演示三种 HttpClient 5 异步请求方式。

    1. package com.wdbyte.httpclient;
    2.  
    3. import java.io.IOException;
    4. import java.nio.CharBuffer;
    5. import java.util.concurrent.CountDownLatch;
    6. import java.util.concurrent.ExecutionException;
    7. import java.util.concurrent.Future;
    8.  
    9. import org.apache.hc.client5.http.async.methods.AbstractCharResponseConsumer;
    10. import org.apache.hc.client5.http.async.methods.SimpleHttpRequest;
    11. import org.apache.hc.client5.http.async.methods.SimpleHttpRequests;
    12. import org.apache.hc.client5.http.async.methods.SimpleHttpResponse;
    13. import org.apache.hc.client5.http.impl.async.CloseableHttpAsyncClient;
    14. import org.apache.hc.client5.http.impl.async.HttpAsyncClients;
    15. import org.apache.hc.core5.concurrent.FutureCallback;
    16. import org.apache.hc.core5.http.ContentType;
    17. import org.apache.hc.core5.http.HttpException;
    18. import org.apache.hc.core5.http.HttpResponse;
    19. import org.apache.hc.core5.http.nio.AsyncRequestProducer;
    20. import org.apache.hc.core5.http.nio.support.AsyncRequestBuilder;
    21.  
    22. /**
    23.  * HttpClient 5 异步请求
    24. * @author https://www.wdbyte.com
    25.  * @date 2022/06/25
    26.  */
    27. public class HttpClient5Async {
    28.  
    29.     public static void main(String[] args) {
    30.         getAsync1("http://httpbin.org/get");
    31.         getAsync2("http://httpbin.org/get");
    32.         getAsync3("http://httpbin.org/get");
    33.     }
    34.  
    35.     /**
    36.      * 异步请求
    37.      *
    38.      * @param url
    39.      * @return
    40.      */
    41.     public static String getAsync1(String url) {
    42.         try (CloseableHttpAsyncClient httpclient = HttpAsyncClients.createDefault()) {
    43.             // 开始 http clinet
    44.             httpclient.start();
    45.             // 执行请求
    46.             SimpleHttpRequest request1 = SimpleHttpRequests.get(url);
    47.             Future<SimpleHttpResponse> future = httpclient.execute(request1, null);
    48.             // 等待直到返回完毕
    49.             SimpleHttpResponse response1 = future.get();
    50.             System.out.println("getAsync1:" + request1.getRequestUri() + "->" + response1.getCode());
    51.         } catch (IOException | ExecutionException | InterruptedException e) {
    52.             throw new RuntimeException(e);
    53.         }
    54.         return null;
    55.     }
    56.  
    57.     /**
    58.      * 异步请求，根据响应情况回调
    59.      *
    60.      * @param url
    61.      * @return
    62.      */
    63.     public static String getAsync2(String url) {
    64.         try (CloseableHttpAsyncClient httpclient = HttpAsyncClients.createDefault()) {
    65.             // 开始 http clinet
    66.             httpclient.start();
    67.             // 根据请求响应情况进行回调操作
    68.             CountDownLatch latch = new CountDownLatch(1);
    69.             SimpleHttpRequest request = SimpleHttpRequests.get(url);
    70.             httpclient.execute(request, new FutureCallback<SimpleHttpResponse>() {
    71.                 @Override
    72.                 public void completed(SimpleHttpResponse response2) {
    73.                     latch.countDown();
    74.                     System.out.println("getAsync2:" + request.getRequestUri() + "->" + response2.getCode());
    75.                 }
    76.  
    77.                 @Override
    78.                 public void failed(Exception ex) {
    79.                     latch.countDown();
    80.                     System.out.println("getAsync2:" + request.getRequestUri() + "->" + ex);
    81.                 }
    82.  
    83.                 @Override
    84.                 public void cancelled() {
    85.                     latch.countDown();
    86.                     System.out.println("getAsync2:" + request.getRequestUri() + " cancelled");
    87.                 }
    88.  
    89.             });
    90.             latch.await();
    91.         } catch (IOException | InterruptedException e) {
    92.             throw new RuntimeException(e);
    93.         }
    94.         return null;
    95.     }
    96.  
    97.     /**
    98.      * 异步请求，对响应流做点什么
    99.      *
    100.      * @param url
    101.      * @return
    102.      */
    103.     public static String getAsync3(String url) {
    104.         try (CloseableHttpAsyncClient httpclient = HttpAsyncClients.createDefault()) {
    105.             // 开始 http clinet
    106.             httpclient.start();
    107.             // 根据请求响应情况进行回调操作
    108.             SimpleHttpRequest request = SimpleHttpRequests.get(url);
    109.  
    110.             CountDownLatch latch = new CountDownLatch(1);
    111.             AsyncRequestProducer producer = AsyncRequestBuilder.get("http://httpbin.org/get").build();
    112.             AbstractCharResponseConsumer<HttpResponse> consumer3 = new AbstractCharResponseConsumer<HttpResponse>() {
    113.  
    114.                 HttpResponse response;
    115.  
    116.                 @Override
    117.                 protected void start(HttpResponse response, ContentType contentType) throws HttpException, IOException {
    118.                     System.out.println("getAsync3: 开始响应....");
    119.                     this.response = response;
    120.                 }
    121.  
    122.                 @Override
    123.                 protected int capacityIncrement() {
    124.                     return Integer.MAX_VALUE;
    125.                 }
    126.  
    127.                 @Override
    128.                 protected void data(CharBuffer data, boolean endOfStream) throws IOException {
    129.                     System.out.println("getAsync3: 收到数据....");
    130.                     // Do something useful
    131.                 }
    132.  
    133.                 @Override
    134.                 protected HttpResponse buildResult() throws IOException {
    135.                     System.out.println("getAsync3: 接收完毕...");
    136.                     return response;
    137.                 }
    138.  
    139.                 @Override
    140.                 public void releaseResources() {
    141.                 }
    142.  
    143.             };
    144.             httpclient.execute(producer, consumer3, new FutureCallback<HttpResponse>() {
    145.  
    146.                 @Override
    147.                 public void completed(HttpResponse response) {
    148.                     latch.countDown();
    149.                     System.out.println("getAsync3: "+request.getRequestUri() + "->" + response.getCode());
    150.                 }
    151.  
    152.                 @Override
    153.                 public void failed(Exception ex) {
    154.                     latch.countDown();
    155.                     System.out.println("getAsync3: "+request.getRequestUri() + "->" + ex);
    156.                 }
    157.  
    158.                 @Override
    159.                 public void cancelled() {
    160.                     latch.countDown();
    161.                     System.out.println("getAsync3: "+request.getRequestUri() + " cancelled");
    162.                 }
    163.  
    164.             });
    165.             latch.await();
    166.         } catch (IOException | InterruptedException e) {
    167.             throw new RuntimeException(e);
    168.         }
    169.         return null;
    170.  
    171.     }
    172. }

    输出结果：

    1. getAsync1:/get->200
    2. getAsync2:/get->200
    3. getAsync3: 开始响应....
    4. getAsync3: 收到数据....
    5. getAsync3: 收到数据....
    6. getAsync3: 收到数据....
    7. getAsync3: 接收完毕...
    8. getAsync3: /get->200

    HttpClient 5 获取 Cookie

    请求 http://httpbin.org/cookies/set/cookieName/www.wdbyte.com 的响应中会带有一个Cookie 信息，其中 name 为 cookieName，value 为 www.wdbyte.com，我们以此用作测试。

    Postman 请求测试，可以看到响应了 Cookie 信息。

     

    下面编写 Java 代码进行请求测试

    1. package com.wdbyte.httpclient;
    2.  
    3. import java.util.List;
    4.  
    5. import org.apache.hc.client5.http.classic.methods.HttpGet;
    6. import org.apache.hc.client5.http.cookie.BasicCookieStore;
    7. import org.apache.hc.client5.http.cookie.Cookie;
    8. import org.apache.hc.client5.http.cookie.CookieStore;
    9. import org.apache.hc.client5.http.impl.classic.CloseableHttpClient;
    10. import org.apache.hc.client5.http.impl.classic.CloseableHttpResponse;
    11. import org.apache.hc.client5.http.impl.classic.HttpClients;
    12. import org.apache.hc.client5.http.impl.cookie.BasicClientCookie;
    13. import org.apache.hc.client5.http.protocol.HttpClientContext;
    14. import org.apache.hc.core5.http.io.entity.EntityUtils;
    15.  
    16. /**
    17.  * 这个例子演示了使用本地HTTP上下文填充, 自定义属性
    18.  */
    19. public class HttpClient5WithCookie {
    20.  
    21.     public static void main(final String[] args) throws Exception {
    22.         try (final CloseableHttpClient httpclient = HttpClients.createDefault()) {
    23.             // 创建一个本地的 Cookie 存储
    24.             final CookieStore cookieStore = new BasicCookieStore();
    25.             // BasicClientCookie clientCookie = new BasicClientCookie("name", "www.wdbyte.com");
    26.             // clientCookie.setDomain("http://httpbin.org/cookies");
    27.             // 过期时间
    28.             // clientCookie.setExpiryDate(new Date());
    29.             // 添加到本地 Cookie
    30.             // cookieStore.addCookie(clientCookie);
    31.  
    32.             // 创建本地 HTTP 请求上下文 HttpClientContext
    33.             final HttpClientContext localContext = HttpClientContext.create();
    34.             // 绑定 cookieStore 到 localContext
    35.             localContext.setCookieStore(cookieStore);
    36.  
    37.             final HttpGet httpget = new HttpGet("http://httpbin.org/cookies/set/cookieName/www.wdbyte.com");
    38.             System.out.println("执行请求 " + httpget.getMethod() + " " + httpget.getUri());
    39.  
    40.             // 获取 Coolie 信息
    41.             try (final CloseableHttpResponse response = httpclient.execute(httpget, localContext)) {
    42.                 System.out.println("----------------------------------------");
    43.                 System.out.println(response.getCode() + " " + response.getReasonPhrase());
    44.                 final List<Cookie> cookies = cookieStore.getCookies();
    45.                 for (int i = 0; i < cookies.size(); i++) {
    46.                     System.out.println("Local cookie: " + cookies.get(i));
    47.                 }
    48.                 EntityUtils.consume(response.getEntity());
    49.             }
    50.         }
    51.     }
    52.  
    53. }

    输出结果：

    1. 执行请求 GET http://httpbin.org/cookies/set/cookieName/www.wdbyte.com
    2. ----------------------------------------
    3. 200 OK
    4. Local cookie: [name: cookieName; value: www.wdbyte.com; domain: httpbin.org; path: /; expiry: null]

    HttpClient 5 读取文件内容请求

    准备一个 JSON 内容格式的文件 params.json。

    {"name":"www.wdbyte.com"}

    读取这个文件作为请求参数发起请求。

    1. package com.wdbyte.httpclient;
    2.  
    3. import java.io.File;
    4. import java.io.FileInputStream;
    5.  
    6. import org.apache.hc.client5.http.classic.methods.HttpPost;
    7. import org.apache.hc.client5.http.impl.classic.CloseableHttpClient;
    8. import org.apache.hc.client5.http.impl.classic.CloseableHttpResponse;
    9. import org.apache.hc.client5.http.impl.classic.HttpClients;
    10. import org.apache.hc.core5.http.ContentType;
    11. import org.apache.hc.core5.http.io.entity.EntityUtils;
    12. import org.apache.hc.core5.http.io.entity.FileEntity;
    13. import org.apache.hc.core5.http.io.entity.InputStreamEntity;
    14.  
    15. /**
    16.  * 加载数据流作为 POST 请求参数
    17.  */
    18. public class HttpClient5ChunkEncodedPost {
    19.  
    20.     public static void main(final String[] args) throws Exception {
    21.         String params = "/Users/darcy/params.json";
    22.  
    23.         try (final CloseableHttpClient httpclient = HttpClients.createDefault()) {
    24.             final HttpPost httppost = new HttpPost("http://httpbin.org/post");
    25.  
    26.             final InputStreamEntity reqEntity = new InputStreamEntity(new FileInputStream(params), -1,
    27.                 ContentType.APPLICATION_JSON);
    28.             // 也可以使用 FileEntity 的形式
    29.             // FileEntity reqEntity = new FileEntity(new File(params), ContentType.APPLICATION_JSON);
    30.  
    31.             httppost.setEntity(reqEntity);
    32.  
    33.             System.out.println("执行请求 " + httppost.getMethod() + " " + httppost.getUri());
    34.             try (final CloseableHttpResponse response = httpclient.execute(httppost)) {
    35.                 System.out.println("----------------------------------------");
    36.                 System.out.println(response.getCode() + " " + response.getReasonPhrase());
    37.                 System.out.println(EntityUtils.toString(response.getEntity()));
    38.             }
    39.         }
    40.     }
    41. }

    输出结果：

    1. 执行请求 POST http://httpbin.org/post
    2. ----------------------------------------
    3. 200 OK
    4. {
    5.   "args": {}, 
    6.   "data": "{\"name\":\"www.wdbyte.com\"}\n", 
    7.   "files": {}, 
    8.   "form": {}, 
    9.   "headers": {
    10.     "Accept-Encoding": "gzip, x-gzip, deflate", 
    11.     "Content-Length": "26", 
    12.     "Content-Type": "application/json; charset=UTF-8", 
    13.     "Host": "httpbin.org", 
    14.     "User-Agent": "Apache-HttpClient/5.1.3 (Java/1.8.0_151)", 
    15.     "X-Amzn-Trace-Id": "Root=1-62ee4d95-1f956d4303cea09c52694c86"
    16.   }, 
    17.   "json": {
    18.     "name": "www.wdbyte.com"
    19.   }, 
    20.   "origin": "42.120.74.238", 
    21.   "url": "http://httpbin.org/post"
    22. }

    HttpClient 5 表单登录

    表单登录可以理解为发起一个携带了认证信息的请求，然后得到响应的 Cookie 的过程。当然这里不仅仅适用于表单登录，也可以是简单的发起一个携带了表单信息的请求。

    本应该使用 POST 请求发送表单参数测试，但是在 httpbin.org 中没有对应的接口用于测试，所以这里换成了 GET 请求

    示例代码：

    1. package com.wdbyte.httpclient;
    2.  
    3. import java.util.ArrayList;
    4. import java.util.List;
    5.  
    6. import org.apache.hc.client5.http.classic.methods.HttpGet;
    7. import org.apache.hc.client5.http.cookie.BasicCookieStore;
    8. import org.apache.hc.client5.http.cookie.Cookie;
    9. import org.apache.hc.client5.http.entity.UrlEncodedFormEntity;
    10. import org.apache.hc.client5.http.impl.classic.CloseableHttpClient;
    11. import org.apache.hc.client5.http.impl.classic.CloseableHttpResponse;
    12. import org.apache.hc.client5.http.impl.classic.HttpClients;
    13. import org.apache.hc.core5.http.HttpEntity;
    14. import org.apache.hc.core5.http.NameValuePair;
    15. import org.apache.hc.core5.http.io.entity.EntityUtils;
    16. import org.apache.hc.core5.http.message.BasicNameValuePair;
    17.  
    18. /**
    19.  * 演示基于表单的登录
    20.  * 
    21.  * @author https://www.wdbyte.com
    22.  */
    23. public class HttpClient5FormLogin {
    24.  
    25.     public static void main(final String[] args) throws Exception {
    26.         final BasicCookieStore cookieStore = new BasicCookieStore();
    27.         try (final CloseableHttpClient httpclient = HttpClients.custom()
    28.                 .setDefaultCookieStore(cookieStore)
    29.                 .build()) {
    30.  
    31.             // 本应该使用 POST 请求发送表单参数，但是在 httpbin.org 中没有对应的接口用于测试，所以这里换成了 GET 请求
    32.             // HttpPost httpPost = new HttpPost("http://httpbin.org/cookies/set/username/wdbyte.com");
    33.             HttpGet httpPost = new HttpGet("http://httpbin.org/cookies/set/username/wdbyte.com");
    34.             // POST 表单请求参数
    35.             List<NameValuePair> nvps = new ArrayList<>();
    36.             nvps.add(new BasicNameValuePair("username", "wdbyte.com"));
    37.             nvps.add(new BasicNameValuePair("password", "secret"));
    38.             httpPost.setEntity(new UrlEncodedFormEntity(nvps));
    39.  
    40.             try (final CloseableHttpResponse response2 = httpclient.execute(httpPost)) {
    41.                 final HttpEntity entity = response2.getEntity();
    42.  
    43.                 System.out.println("Login form get: " + response2.getCode() + " " + response2.getReasonPhrase());
    44.                 System.out.println("当前响应信息 "+EntityUtils.toString(entity));;
    45.  
    46.                 System.out.println("Post 登录 Cookie:");
    47.                 final List<Cookie> cookies = cookieStore.getCookies();
    48.                 if (cookies.isEmpty()) {
    49.                     System.out.println("None");
    50.                 } else {
    51.                     for (int i = 0; i < cookies.size(); i++) {
    52.                         System.out.println("- " + cookies.get(i));
    53.                     }
    54.                 }
    55.             }
    56.         }
    57.     }
    58. }

    输出结果：

    1. Login form get: 200 OK
    2. 当前响应信息 {
    3.   "cookies": {
    4.     "username": "wdbyte.com"
    5.   }
    6. }
    7.  
    8. Post 登录 Cookie:
    9. - [name: username; value: wdbyte.com; domain: httpbin.org; path: /; expiry: null]

    HttpClient 5 Basic Authorization

    HTTP 基本认证（Basic Authorization）是一种比较简单的认证实现，主要流程如下

    1. 1. 请求一个需要进行基本认证的 HTTP 接口，但是没有携带认证信息。

    2. 2. 此时会响应 401 状态码，并在响应 header 中的 WWW-Authenticate 提示需要进行基本认证。

    3. 3. 用户把需要提交认证信息进行冒号拼接，然后进行 base64 编码，再在得到的字符串开头拼接上 Basic 放入请求头 Authorization 中。

    4. 4. 认证成功，响应成功。

    你可以通过浏览器打开下面这个 URL 进行基本认证测试。

    http://httpbin.org/basic-auth/admin/123456

    在 Apache HttpClient 5 中的实现方式。

    1. package com.wdbyte.httpclient;
    2.  
    3. import org.apache.hc.client5.http.auth.AuthScope;
    4. import org.apache.hc.client5.http.auth.UsernamePasswordCredentials;
    5. import org.apache.hc.client5.http.classic.methods.HttpGet;
    6. import org.apache.hc.client5.http.impl.auth.BasicCredentialsProvider;
    7. import org.apache.hc.client5.http.impl.classic.CloseableHttpClient;
    8. import org.apache.hc.client5.http.impl.classic.CloseableHttpResponse;
    9. import org.apache.hc.client5.http.impl.classic.HttpClients;
    10. import org.apache.hc.core5.http.io.entity.EntityUtils;
    11.  
    12. /**
    13.  * 一个简单的示例,它使用HttpClient执行HTTP请求;
    14.  * 一个需要进行用户身份验证的目标站点。
    15.  */
    16. public class HttpClient5BasicAuthentication {
    17.  
    18.     public static void main(final String[] args) throws Exception {
    19.         final BasicCredentialsProvider credsProvider = new BasicCredentialsProvider();
    20.         credsProvider.setCredentials(
    21.                 new AuthScope("httpbin.org", 80),
    22.                 new UsernamePasswordCredentials("admin", "123456".toCharArray()));
    23.         try (final CloseableHttpClient httpclient = HttpClients.custom()
    24.                 .setDefaultCredentialsProvider(credsProvider)
    25.                 .build()) {
    26.             final HttpGet httpget = new HttpGet("http://httpbin.org/basic-auth/admin/123456");
    27.  
    28.             System.out.println("执行请求" + httpget.getMethod() + " " + httpget.getUri());
    29.             try (final CloseableHttpResponse response = httpclient.execute(httpget)) {
    30.                 System.out.println("----------------------------------------");
    31.                 System.out.println(response.getCode() + " " + response.getReasonPhrase());
    32.                 System.out.println(EntityUtils.toString(response.getEntity()));
    33.             }
    34.         }
    35.     }
    36. }

    输出结果：

    1. 执行请求GET http://httpbin.org/basic-auth/user/passwd
    2. ----------------------------------------
    3. 200 OK
    4. {
    5.   "authenticated": true, 
    6.   "user": "user"
    7. }

    通过抓包可以看到完整的 HTTP 请求响应过程。

    1. // 请求
    2. GET /basic-auth/user/passwd HTTP/1.1
    3. Accept-Encoding: gzip, x-gzip, deflate
    4. Host: httpbin.org
    5. Connection: keep-alive
    6. User-Agent: Apache-HttpClient/5.1.3 (Java/1.8.0_151)
    7. // 响应
    8. HTTP/1.1 401 UNAUTHORIZED
    9. Date: Sat, 06 Aug 2022 08:25:33 GMT
    10. Content-Length: 0
    11. Connection: keep-alive
    12. Server: gunicorn/19.9.0
    13. WWW-Authenticate: Basic realm="Fake Realm"
    14. Access-Control-Allow-Origin: *
    15. Access-Control-Allow-Credentials: true
    16. // 请求
    17. GET /basic-auth/user/passwd HTTP/1.1
    18. Host: httpbin.org
    19. Connection: keep-alive
    20. User-Agent: Apache-HttpClient/5.1.3 (Java/1.8.0_151)
    21. Authorization: Basic dXNlcjpwYXNzd2Q=
    22. // 响应
    23. HTTP/1.1 200 OK
    24. Date: Sat, 06 Aug 2022 08:25:33 GMT
    25. Content-Type: application/json
    26. Content-Length: 47
    27. Connection: keep-alive
    28. Server: gunicorn/19.9.0
    29. Access-Control-Allow-Origin: *
    30. Access-Control-Allow-Credentials: true
    31.  
    32. {
    33.   "authenticated": true, 
    34.   "user": "user"
    35. }

    HttpClient 5 Digest Authorization

    HTTP Basic Authorization 的缺点显而易见，密码通过明文传输存在一定的安全风险，Digest Authorization 认证方式解决了明文传输的问题，这里不过多介绍 Digest 的相关内容，通过一个图简单的示意 Digest 认证方式的流程。

     

    Digest 认证流程

    下面是代码演示。

    1. package com.wdbyte.httpclient;
    2.  
    3. import org.apache.hc.client5.http.auth.AuthExchange;
    4. import org.apache.hc.client5.http.auth.AuthScheme;
    5. import org.apache.hc.client5.http.auth.AuthScope;
    6. import org.apache.hc.client5.http.auth.UsernamePasswordCredentials;
    7. import org.apache.hc.client5.http.classic.methods.HttpGet;
    8. import org.apache.hc.client5.http.impl.auth.BasicCredentialsProvider;
    9. import org.apache.hc.client5.http.impl.auth.DigestScheme;
    10. import org.apache.hc.client5.http.impl.classic.CloseableHttpClient;
    11. import org.apache.hc.client5.http.impl.classic.CloseableHttpResponse;
    12. import org.apache.hc.client5.http.impl.classic.HttpClients;
    13. import org.apache.hc.client5.http.protocol.HttpClientContext;
    14. import org.apache.hc.core5.http.HttpHost;
    15. import org.apache.hc.core5.http.io.entity.EntityUtils;
    16.  
    17. /**
    18.  *
    19.  * HttpClient如何验证多个请求的示例
    20.  * 使用相同的摘要方案。在初始请求/响应交换之后
    21.  * 共享相同执行上下文的所有后续请求都可以重用
    22.  * 要向服务器进行身份验证的最后一个摘要nonce值。
    23.  */
    24. public class HttpClient5PreemptiveDigestAuthentication {
    25.  
    26.     public static void main(final String[] args) throws Exception {
    27.         try (final CloseableHttpClient httpclient = HttpClients.createDefault()) {
    28.  
    29.             final HttpHost target = new HttpHost("http", "httpbin.org", 80);
    30.  
    31.             final HttpClientContext localContext = HttpClientContext.create();
    32.             final BasicCredentialsProvider credentialsProvider = new BasicCredentialsProvider();
    33.             credentialsProvider.setCredentials(
    34.                     new AuthScope(target),
    35.                     new UsernamePasswordCredentials("admin", "123456".toCharArray()));
    36.             localContext.setCredentialsProvider(credentialsProvider);
    37.  
    38.             final HttpGet httpget = new HttpGet("http://httpbin.org/digest-auth/auth/admin/123456");
    39.  
    40.             System.out.println("执行请求 " + httpget.getMethod() + " " + httpget.getUri());
    41.             for (int i = 0; i < 2; i++) {
    42.                 try (final CloseableHttpResponse response = httpclient.execute(target, httpget, localContext)) {
    43.                     System.out.println("----------------------------------------");
    44.                     System.out.println(response.getCode() + " " + response.getReasonPhrase());
    45.                     EntityUtils.consume(response.getEntity());
    46.  
    47.                     final AuthExchange authExchange = localContext.getAuthExchange(target);
    48.                     if (authExchange != null) {
    49.                         final AuthScheme authScheme = authExchange.getAuthScheme();
    50.                         if (authScheme instanceof DigestScheme) {
    51.                             final DigestScheme digestScheme = (DigestScheme) authScheme;
    52.                             System.out.println("Nonce: " + digestScheme.getNonce() +
    53.                                     "; count: " + digestScheme.getNounceCount());
    54.                         }
    55.                     }
    56.                 }
    57.             }
    58.         }
    59.     }
    60.  
    61. }

    通过抓包工具可以清晰的看到 2 次请求的流程，在最后一次请求中，直接共享了认证信息，没有再次的重新认证的流程。

    1. // 1. 请求
    2. GET /digest-auth/auth/admin/123456 HTTP/1.1
    3. Accept-Encoding: gzip, x-gzip, deflate
    4. Host: httpbin.org
    5. Connection: keep-alive
    6. User-Agent: Apache-HttpClient/5.1.3 (Java/1.8.0_151)
    7. // 2. 详情，提示认证，给出参数
    8. HTTP/1.1 401 UNAUTHORIZED
    9. Date: Fri, 12 Aug 2022 07:11:06 GMT
    10. Content-Type: text/html; charset=utf-8
    11. Content-Length: 0
    12. Connection: keep-alive
    13. Server: gunicorn/19.9.0
    14. WWW-Authenticate: Digest realm="me@kennethreitz.com", nonce="8dc5e7974a86a6fcc3cf73230b0c4a93", qop="auth", opaque="64b7f68b386c3acc38131f7472aa2079", algorithm=MD5, stale=FALSE
    15. Set-Cookie: stale_after=never; Path=/
    16. Set-Cookie: fake=fake_value; Path=/
    17. Access-Control-Allow-Origin: *
    18. Access-Control-Allow-Credentials: true
    19. // 3. 参数+密码 加密后再次请求
    20. GET /digest-auth/auth/admin/123456 HTTP/1.1
    21. Host: httpbin.org
    22. Connection: keep-alive
    23. User-Agent: Apache-HttpClient/5.1.3 (Java/1.8.0_151)
    24. Cookie: fake=fake_value; stale_after=never
    25. Authorization: Digest username="admin", realm="me@kennethreitz.com", nonce="8dc5e7974a86a6fcc3cf73230b0c4a93", uri="/digest-auth/auth/admin/123456", response="7c6726f8ac54c1ba28e19c71b2fc7338", qop=auth, nc=00000001, cnonce="2fa61501d47a9d39", algorithm=MD5, opaque="64b7f68b386c3acc38131f7472aa2079"
    26. // 4. 认证成功，响应
    27. HTTP/1.1 200 OK
    28. Date: Fri, 12 Aug 2022 07:11:08 GMT
    29. Content-Type: application/json
    30. Content-Length: 48
    31. Connection: keep-alive
    32. Server: gunicorn/19.9.0
    33. Set-Cookie: fake=fake_value; Path=/
    34. Set-Cookie: stale_after=never; Path=/
    35. Access-Control-Allow-Origin: *
    36. Access-Control-Allow-Credentials: true
    37.  
    38. {
    39.   "authenticated": true, 
    40.   "user": "admin"
    41. }
    42. // 5. 再次请求，共享了登录状态。
    43. GET /digest-auth/auth/admin/123456 HTTP/1.1
    44. Accept-Encoding: gzip, x-gzip, deflate
    45. Host: httpbin.org
    46. Connection: keep-alive
    47. User-Agent: Apache-HttpClient/5.1.3 (Java/1.8.0_151)
    48. Cookie: fake=fake_value; stale_after=never
    49. Authorization: Digest username="admin", realm="me@kennethreitz.com", nonce="8dc5e7974a86a6fcc3cf73230b0c4a93", uri="/digest-auth/auth/admin/123456", response="9955ac79f6a51a876a326449447f549d", qop=auth, nc=00000002, cnonce="2fa61501d47a9d39", algorithm=MD5, opaque="64b7f68b386c3acc38131f7472aa2079"
    50. // 5. 认证成功，响应
    51. HTTP/1.1 200 OK
    52. Date: Fri, 12 Aug 2022 07:11:09 GMT
    53. Content-Type: application/json
    54. Content-Length: 48
    55. Connection: keep-alive
    56. Server: gunicorn/19.9.0
    57. Set-Cookie: fake=fake_value; Path=/
    58. Set-Cookie: stale_after=never; Path=/
    59. Access-Control-Allow-Origin: *
    60. Access-Control-Allow-Credentials: true
    61.  
    62. {
    63.   "authenticated": true, 
    64.   "user": "admin"
    65. }

    HttpClient 5 拦截器

    HttpClient 5 中的拦截器可以对请求过程的各个阶段进行拦截处理，通过 HttpClientBuilder 中的关于 Interceptor 的方法可以看到可以进行拦截的节点。

     

    HttpClient5 拦截器

    下面编写一个示例，发起三次请求，每次请求都在请求头 herader 中增加一个 request-id 参数，然后对 request-id 值为 2 的请求直接响应 404 结束。

    1. package com.wdbyte.httpclient;
    2.  
    3. import java.io.IOException;
    4. import java.util.concurrent.atomic.AtomicLong;
    5.  
    6. import org.apache.hc.client5.http.classic.ExecChain;
    7. import org.apache.hc.client5.http.classic.ExecChain.Scope;
    8. import org.apache.hc.client5.http.classic.ExecChainHandler;
    9. import org.apache.hc.client5.http.classic.methods.HttpGet;
    10. import org.apache.hc.client5.http.impl.ChainElement;
    11. import org.apache.hc.client5.http.impl.classic.CloseableHttpClient;
    12. import org.apache.hc.client5.http.impl.classic.CloseableHttpResponse;
    13. import org.apache.hc.client5.http.impl.classic.HttpClients;
    14. import org.apache.hc.core5.http.ClassicHttpRequest;
    15. import org.apache.hc.core5.http.ClassicHttpResponse;
    16. import org.apache.hc.core5.http.ContentType;
    17. import org.apache.hc.core5.http.EntityDetails;
    18. import org.apache.hc.core5.http.Header;
    19. import org.apache.hc.core5.http.HttpEntity;
    20. import org.apache.hc.core5.http.HttpException;
    21. import org.apache.hc.core5.http.HttpRequest;
    22. import org.apache.hc.core5.http.HttpRequestInterceptor;
    23. import org.apache.hc.core5.http.HttpStatus;
    24. import org.apache.hc.core5.http.io.entity.EntityUtils;
    25. import org.apache.hc.core5.http.io.entity.StringEntity;
    26. import org.apache.hc.core5.http.message.BasicClassicHttpResponse;
    27. import org.apache.hc.core5.http.protocol.HttpContext;
    28.  
    29. /**
    30.  * 展示如何在请求和响应时进行拦截进行自定义处理。
    31.  */
    32. public class HttpClient5Interceptors {
    33.  
    34.     public static void main(final String[] args) throws Exception {
    35.         try (final CloseableHttpClient httpclient = HttpClients.custom()
    36.             // 添加一个请求 id 到请求 header
    37.             .addRequestInterceptorFirst(new HttpRequestInterceptor() {
    38.                 private final AtomicLong count = new AtomicLong(0);
    39.                 @Override
    40.                 public void process(
    41.                     final HttpRequest request,
    42.                     final EntityDetails entity,
    43.                     final HttpContext context) throws HttpException, IOException {
    44.                     request.setHeader("request-id", Long.toString(count.incrementAndGet()));
    45.                 }
    46.             })
    47.             .addExecInterceptorAfter(ChainElement.PROTOCOL.name(), "custom", new ExecChainHandler() {
    48.                 // 请求 id 为 2 的，模拟 404 响应，并自定义响应的内容。
    49.                 @Override
    50.                 public ClassicHttpResponse execute(
    51.                     final ClassicHttpRequest request,
    52.                     final Scope scope,
    53.                     final ExecChain chain) throws IOException, HttpException {
    54.  
    55.                     final Header idHeader = request.getFirstHeader("request-id");
    56.                     if (idHeader != null && "2".equalsIgnoreCase(idHeader.getValue())) {
    57.                         final ClassicHttpResponse response = new BasicClassicHttpResponse(HttpStatus.SC_NOT_FOUND,
    58.                             "Oppsie");
    59.                         response.setEntity(new StringEntity("bad luck", ContentType.TEXT_PLAIN));
    60.                         return response;
    61.                     } else {
    62.                         return chain.proceed(request, scope);
    63.                     }
    64.                 }
    65.             })
    66.             .build()) {
    67.  
    68.             for (int i = 0; i < 3; i++) {
    69.                 final HttpGet httpget = new HttpGet("http://httpbin.org/get");
    70.  
    71.                 try (final CloseableHttpResponse response = httpclient.execute(httpget)) {
    72.                     System.out.println("----------------------------------------");
    73.                     System.out.println("执行请求 " + httpget.getMethod() + " " + httpget.getUri());
    74.                     System.out.println(response.getCode() + " " + response.getReasonPhrase());
    75.                     System.out.println(EntityUtils.toString(response.getEntity()));
    76.                 }
    77.             }
    78.         }
    79.     }
    80.  
    81. }

    输出结果。

    1. ----------------------------------------
    2. 执行请求 GET http://httpbin.org/get
    3. 200 OK
    4. {
    5.   "args": {}, 
    6.   "headers": {
    7.     "Accept-Encoding": "gzip, x-gzip, deflate", 
    8.     "Host": "httpbin.org", 
    9.     "Request-Id": "1", 
    10.     "User-Agent": "Apache-HttpClient/5.1.3 (Java/1.8.0_151)", 
    11.     "X-Amzn-Trace-Id": "Root=1-62f615ba-658ccd42182d22534dbba82c"
    12.   }, 
    13.   "origin": "42.120.75.221", 
    14.   "url": "http://httpbin.org/get"
    15. }
    16.  
    17. ----------------------------------------
    18. 执行请求 GET http://httpbin.org/get
    19. 404 Oppsie
    20. bad luck
    21. ----------------------------------------
    22. 执行请求 GET http://httpbin.org/get
    23. 200 OK
    24. {
    25.   "args": {}, 
    26.   "headers": {
    27.     "Accept-Encoding": "gzip, x-gzip, deflate", 
    28.     "Host": "httpbin.org", 
    29.     "Request-Id": "3", 
    30.     "User-Agent": "Apache-HttpClient/5.1.3 (Java/1.8.0_151)", 
    31.     "X-Amzn-Trace-Id": "Root=1-62f615bb-4eb6ba10736ace0e21d0cb8c"
    32.   }, 
    33.   "origin": "42.120.75.221", 
    34.   "url": "http://httpbin.org/get"
    35. }

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  • 原文地址：https://blog.csdn.net/hebiwen95/article/details/126405108