Apache HttpClient - Cookie 管理

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Cookie 是存储在客户端计算机上的文本文件，保留它们用于各种信息跟踪目的。

HttpClient 提供对 cookie 的支持，您可以创建和管理 cookie。

创建 cookie

按照下面给出的步骤使用 HttpClient 库创建 cookie。

第 1 步 - 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（该接口的默认实现）来创建 cookie 存储。

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

第 2 步 - 创建 ClientCookie 对象

ClientCookie除了具有cookie的功能外，还可以获取服务器中的原始cookie。您可以通过实例化BasicClientCookie类来创建客户端 cookie 。对于此类的构造函数，您需要传递您想要存储在该特定 cookie 中的键值对。

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

第 3 步 - 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、到期日期、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);

第 4 步 - 将 cookie 添加到 cookie 存储区

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

将所需的 cookie 添加到 Cookiestore中。

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

例子

以下示例演示了如何创建 cookie 并将它们添加到 cookie 存储中。在这里，我们创建了一个 cookie 存储，通过设置域和路径值来创建一堆 cookie，并将这些添加到 cookie 存储中。

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asicCookieStore类的getCookies()方法将 cookie 添加到 cookie 存储中。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());
}

例子

以下示例演示了如何从 cookie 存储中检索 cookie。在这里，我们将一堆 cookie 添加到 cookie 存储中并检索它们。

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

执行时，该程序生成以下输出 -

[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]