为什么HttpClient post请求返回的header中只有一个Set-Cookie，而用浏览器中请求返回的header中Set-Cookie有多个

这可能是因为浏览器在发送请求时会自动添加一些额外的头信息，例如User-Agent、Referer、Accept等，这些头信息可能会影响服务器返回的响应头信息。

另外，HttpClient发送的请求可以通过设置请求头信息来模拟浏览器发送的请求，例如设置User-Agent、Referer等头信息，这样可能会使服务器返回更多的Set-Cookie头信息。

相关问题

HttpClient发送Post请求并携带cookie

以下是一个使用HttpClient发送Post请求并携带cookie的示例代码：

import org.apache.http.HttpEntity;
import org.apache.http.HttpResponse;
import org.apache.http.client.CookieStore;
import org.apache.http.client.HttpClient;
import org.apache.http.client.config.RequestConfig;
import org.apache.http.client.entity.UrlEncodedFormEntity;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.cookie.Cookie;
import org.apache.http.impl.client.BasicCookieStore;
import org.apache.http.impl.client.HttpClientBuilder;
import org.apache.http.message.BasicNameValuePair;
import org.apache.http.util.EntityUtils;

import java.util.ArrayList;
import java.util.List;

public class HttpClientUtil {

    public static void main(String[] args) throws Exception {
        // 创建HttpClient实例
        HttpClient httpClient = HttpClientBuilder.create().build();

        // 创建CookieStore实例
        CookieStore cookieStore = new BasicCookieStore();

        // 创建HttpPost实例
        HttpPost httpPost = new HttpPost("http://example.com/login");

        // 设置请求参数
        RequestConfig requestConfig = RequestConfig.custom()
                .setConnectTimeout(5000).setConnectionRequestTimeout(5000)
                .setSocketTimeout(5000).build();
        httpPost.setConfig(requestConfig);

        // 设置请求头
        httpPost.setHeader("Content-Type", "application/x-www-form-urlencoded");

        // 设置请求体参数
        List<BasicNameValuePair> parameters = new ArrayList<>();
        parameters.add(new BasicNameValuePair("username", "example"));
        parameters.add(new BasicNameValuePair("password", "password"));
        UrlEncodedFormEntity formEntity = new UrlEncodedFormEntity(parameters);
        httpPost.setEntity(formEntity);

        // 执行HttpPost请求
        HttpResponse httpResponse = httpClient.execute(httpPost);

        // 获取响应实体
        HttpEntity httpEntity = httpResponse.getEntity();
        if (httpEntity != null) {
            String response = EntityUtils.toString(httpEntity);
            System.out.println(response);
        }

        // 获取Cookie
        List<Cookie> cookies = cookieStore.getCookies();

        // 创建HttpPost实例
        httpPost = new HttpPost("http://example.com/data");

        // 设置请求参数
        requestConfig = RequestConfig.custom()
                .setConnectTimeout(5000).setConnectionRequestTimeout(5000)
                .setSocketTimeout(5000).build();
        httpPost.setConfig(requestConfig);

        // 设置请求头
        httpPost.setHeader("Content-Type", "application/json");
        httpPost.setHeader("Accept", "application/json");

        // 设置请求体参数
        String requestBody = "{\"key\":\"value\"}";
        httpPost.setEntity(new StringEntity(requestBody, ContentType.APPLICATION_JSON));

        // 设置Cookie
        httpClient = HttpClientBuilder.create().setDefaultCookieStore(cookieStore).build();

        // 执行HttpPost请求
        httpResponse = httpClient.execute(httpPost);

        // 获取响应实体
        httpEntity = httpResponse.getEntity();
        if (httpEntity != null) {
            String response = EntityUtils.toString(httpEntity);
            System.out.println(response);
        }
    }

}

httpclient获取cookie

HttpClient可以通过以下步骤获取cookie：

1. 创建HttpClient对象。

2. 创建HttpGet或HttpPost对象。

3. 执行HttpGet或HttpPost请求。

4. 获取HttpResponse对象。

5. 获取HttpResponse中的cookie。

以下是示例代码：

// 创建HttpClient对象
CloseableHttpClient httpClient = HttpClients.createDefault();

// 创建HttpGet对象
HttpGet httpGet = new HttpGet("http://www.example.com");

// 执行HttpGet请求
CloseableHttpResponse response = httpClient.execute(httpGet);

// 获取HttpResponse中的cookie
Header[] headers = response.getHeaders("Set-Cookie");
for (Header header : headers) {
    System.out.println(header.getValue());
}

// 关闭HttpResponse和HttpClient
response.close();
httpClient.close();