上面的例子给我换成Java的

好的，下面是一个 Java 代码示例，演示了如何使用 HttpClient 库进行模拟登录操作：

import java.io.IOException;
import java.util.ArrayList;
import java.util.List;

import org.apache.http.HttpEntity;
import org.apache.http.HttpResponse;
import org.apache.http.NameValuePair;
import org.apache.http.client.CookieStore;
import org.apache.http.client.entity.UrlEncodedFormEntity;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.client.methods.HttpUriRequest;
import org.apache.http.cookie.Cookie;
import org.apache.http.impl.client.BasicCookieStore;
import org.apache.http.impl.client.CloseableHttpClient;
import org.apache.http.impl.client.HttpClients;
import org.apache.http.message.BasicNameValuePair;
import org.apache.http.util.EntityUtils;

public class LoginExample {
    public static void main(String[] args) throws IOException {
        // 创建 HttpClient 实例
        CookieStore cookieStore = new BasicCookieStore();
        CloseableHttpClient httpClient = HttpClients.custom().setDefaultCookieStore(cookieStore).build();

        // 构造登录表单数据
        List<NameValuePair> formParams = new ArrayList<>();
        formParams.add(new BasicNameValuePair("username", "your_username"));
        formParams.add(new BasicNameValuePair("password", "your_password"));
        HttpEntity entity = new UrlEncodedFormEntity(formParams, "UTF-8");

        // 构造登录请求
        HttpPost loginRequest = new HttpPost("https://www.example.com/login");
        loginRequest.setEntity(entity);

        // 发送登录请求，获取 session ID
        HttpResponse loginResponse = httpClient.execute(loginRequest);
        if (loginResponse.getStatusLine().getStatusCode() == 200 && loginResponse.containsHeader("Set-Cookie")) {
            String cookieHeader = loginResponse.getFirstHeader("Set-Cookie").getValue();
            cookieStore.addCookie(parseCookie(cookieHeader));
            
            // 发送后续的请求，使用获取到的 cookie 或 session ID
            HttpUriRequest dataRequest = RequestBuilder.get("https://www.example.com/data")
                    .setHeader("User-Agent", "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/89.0.4389.114 Safari/537.36")
                    .setHeader("Referer", "https://www.example.com")
                    .build();
            HttpResponse dataResponse = httpClient.execute(dataRequest);
            HttpEntity dataEntity = dataResponse.getEntity();
            String data = EntityUtils.toString(dataEntity);
            EntityUtils.consume(dataEntity);
            System.out.println(data);
        }

        // 关闭 HttpClient 实例
        httpClient.close();
    }

    private static Cookie parseCookie(String cookieHeader) {
        String[] parts = cookieHeader.split(";");
        String name = parts[0].split("=")[0];
        String value = parts[0].split("=")[1];
        String path = "/";
        String domain = "www.example.com";
        boolean secure = false;
        Cookie cookie = new Cookie(name, value, domain, path, null, secure);
        return cookie;
    }
}

在上面的代码中，我们首先创建了一个 HttpClient 实例，并使用 CookieStore 来保存会话的 Cookie。然后，我们构造了登录表单数据，并通过 HttpPost 请求发送登录请求。如果登录成功，则可以获取到 session ID，并将其保存在 CookieStore 中。在后续的请求中，我们使用 RequestBuilder 构造了一个 GET 请求，并在 headers 中设置了伪装的 User-Agent 和 Referer，并将获取到的 cookie 或 session ID 添加到 Cookie 中，以模拟用户的访问行为。最后，我们通过 EntityUtils.toString() 方法获取到响应数据，并打印出来。