Apache HttpClient - Cookie 管理



Cookie 是存储在客户端计算机上的文本文件,用于各种信息跟踪目的。

HttpClient 提供了对 Cookie 的支持,您可以创建和管理 Cookie。

创建 Cookie

请按照以下步骤使用 HttpClient 库创建 Cookie。

步骤 1 - 创建 CookieStore 对象

CookieStore 接口表示 Cookie 对象的抽象存储。您可以通过实例化BasicCookieStore 类(此接口的默认实现)来创建一个 Cookie 存储。

//Creating the CookieStore object
CookieStore cookieStore = new BasicCookieStore();

步骤 2 - 创建 ClientCookie 对象

除了 Cookie 的功能外,ClientCookie 还可以获取服务器中的原始 Cookie。您可以通过实例化BasicClientCookie 类来创建一个客户端 Cookie。在这个类的构造函数中,您需要传递您希望存储在该特定 Cookie 中的键值对。

//Creating client cookie
BasicClientCookie clientCookie = new BasicClientCookie("name","Raju");

步骤 3 - 设置 Cookie 的值

对于客户端 Cookie,您可以使用相应的方法设置/删除路径、值、版本、过期日期、域、注释和属性。

Calendar myCal = new GregorianCalendar(2018, 9, 26);
Date expiryDate = myCal.getTime();
clientcookie.setExpiryDate(expiryDate);
clientcookie.setPath("/");
clientcookie.setSecure(true);
clientcookie.setValue("25");
clientcookie.setVersion(5);

步骤 4 - 将 Cookie 添加到 Cookie 存储

您可以使用BasicCookieStore 类的addCookie() 方法将 Cookie 添加到 Cookie 存储。

将所需的 Cookie 添加到CookieStore

//Adding the created cookies to cookie store
cookiestore.addCookie(clientcookie);

示例

以下示例演示如何创建 Cookie 并将它们添加到 Cookie 存储。在这里,我们创建了一个 Cookie 存储,通过设置域和路径值创建了一组 Cookie,并将它们添加到 Cookie 存储。

import org.apache.http.client.CookieStore;
import org.apache.http.impl.client.BasicCookieStore;
import org.apache.http.impl.cookie.BasicClientCookie;

public class CookieHandlingExample {
   
   public static void main(String args[]) throws Exception{
      
      //Creating the CookieStore object
      CookieStore cookiestore = new BasicCookieStore();
 
      //Creating client cookies
      BasicClientCookie clientcookie1 = new BasicClientCookie("name","Raju");
      BasicClientCookie clientcookie2 = new BasicClientCookie("age","28");
      BasicClientCookie clientcookie3 = new BasicClientCookie("place","Hyderabad");

      //Setting domains and paths to the created cookies
      clientcookie1.setDomain(".sample.com");
      clientcookie2.setDomain(".sample.com");
      clientcookie3.setDomain(".sample.com");

      clientcookie1.setPath("/");
      clientcookie2.setPath("/");
      clientcookie3.setPath("/");
 
      //Adding the created cookies to cookie store
      cookiestore.addCookie(clientcookie1);
      cookiestore.addCookie(clientcookie2);
      cookiestore.addCookie(clientcookie3);
   }
}

检索 Cookie

您可以使用BasicCookieStore 类的getCookies() 方法获取添加到 Cookie 存储的 Cookie。此方法返回一个列表,其中包含 Cookie 存储中的所有 Cookie。

您可以使用迭代器打印 Cookie 存储的内容,如下所示:

//Retrieving the cookies
List list = cookieStore.getCookies();

//Creating an iterator to the obtained list
Iterator it = list.iterator();
while(it.hasNext()) {
   System.out.println(it.next());
}

示例

以下示例演示如何从 Cookie 存储中检索 Cookie。在这里,我们将一堆 Cookie 添加到 Cookie 存储中,然后将其检索回来。

import org.apache.http.client.CookieStore;
import org.apache.http.impl.client.BasicCookieStore;
import org.apache.http.impl.cookie.BasicClientCookie;

public class CookieHandlingExample {
 
   public static void main(String args[]) throws Exception{
      
      //Creating the CookieStore object
      CookieStore cookiestore = new BasicCookieStore();
      
      //Creating client cookies
      BasicClientCookie clientcookie1 = new BasicClientCookie("name","Raju");
      BasicClientCookie clientcookie2 = new BasicClientCookie("age","28");
      BasicClientCookie clientcookie3 = new BasicClientCookie("place","Hyderabad");

      //Setting domains and paths to the created cookies
      clientcookie1.setDomain(".sample.com");
      clientcookie2.setDomain(".sample.com");
      clientcookie3.setDomain(".sample.com");

      clientcookie1.setPath("/");
      clientcookie2.setPath("/");
      clientcookie3.setPath("/");
 
      //Adding the created cookies to cookie store
      cookiestore.addCookie(clientcookie1);
      cookiestore.addCookie(clientcookie2);
      cookiestore.addCookie(clientcookie3);
   }
}

输出

执行此程序后,将生成以下输出:

[version: 0][name: age][value: 28][domain: .sample.com][path: /][expiry: null]
[version: 0][name: name][value: Raju][domain: my.example.com][path: /][expiry:
null]
[version: 0][name: place][value: Hyderabad][domain: .sample.com][path:
/][expiry: null]
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