如何使用HTTURL连接以Apache HTTPcli客LIB相同的方式编写POST请求

我正试图向一个网站发出一个帖子请求。作为对post请求的响应,我希望得到一些json数据。

使用apache的httpclient库,我可以毫无问题地做到这一点。响应数据是json,所以我只是解析它。

package com.mydomain.myapp;

import java.io.BufferedReader;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
import org.apache.http.HttpEntity;
import org.apache.http.client.methods.CloseableHttpResponse;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.impl.client.CloseableHttpClient;
import org.apache.http.impl.client.HttpClients;
import org.apache.http.util.EntityUtils;

public class MyApp {

    private static String extract(String patternString, String target) {

        Pattern pattern = Pattern.compile(patternString);
        Matcher matcher = pattern.matcher(target);
        matcher.find();
        return matcher.group(1);
    }

    private String getResponse(InputStream stream) throws Exception {

        BufferedReader in = new BufferedReader(new InputStreamReader(stream));
        String inputLine;
        StringBuffer responseStringBuffer = new StringBuffer();
        while ((inputLine = in.readLine()) != null) {
            responseStringBuffer.append(inputLine);
        }
        in.close();
        return responseStringBuffer.toString();
    }

    private final static String BASE_URL = "https://www.volkswagen-car-net.com";
    private final static String BASE_GUEST_URL = "/portal/en_GB/web/guest/home";

    private void run() throws Exception {

        CloseableHttpClient client = HttpClients.createDefault();
        HttpGet httpGet = new HttpGet(BASE_URL + BASE_GUEST_URL);
        CloseableHttpResponse getResponse = client.execute(httpGet);
        HttpEntity responseEntity = getResponse.getEntity();
        String data = getResponse(responseEntity.getContent());
        EntityUtils.consume(responseEntity);

        String csrf = extract("<meta name=\"_csrf\" content=\"(.*)\"/>", data);
        System.out.println(csrf);

        HttpPost post = new HttpPost(BASE_URL + "/portal/web/guest/home/-/csrftokenhandling/get-login-url");
        post.setHeader("Accept", "text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,image/apng,*/*;q=0.8");
        post.setHeader("User-Agent'", "Mozilla/5.0 (Linux; Android 6.0.1; D5803 Build/23.5.A.1.291; wv) AppleWebKit/537.36 (KHTML, like Gecko) Version/4.0 Chrome/63.0.3239.111 Mobile Safari/537.36");
        post.setHeader("Referer", BASE_URL + "/portal");
        post.setHeader("X-CSRF-Token", csrf);

        CloseableHttpResponse postResponse = client.execute(post);
        HttpEntity postResponseEntity = postResponse.getEntity();
        String postData = getResponse(postResponseEntity.getContent());
        System.out.println(postData);
        EntityUtils.consume(postResponseEntity);
        postResponse.close();
    }

    public static void main(String[] args) throws Exception {

        MyApp myApp = new MyApp();
        myApp.run();
    }
}

但是我不能在我的项目中使用HtpPosiver库。我需要能够用“just”httpurlconnection做同样的事情。

但是,httpclient库有一些我无法理解的魔力。因为使用httpurlconnection对我的post请求的响应只是重定向到另一个网页alltoghter。

有人能给我指出正确的方向吗?

下面是我当前的httpurlconnection尝试:

package com.mydomain.myapp;

import java.io.BufferedReader;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.net.HttpURLConnection;
import java.net.URL;
import java.util.regex.Matcher;
import java.util.regex.Pattern;

public class MyApp {

    private static String extract(String patternString, String target) {

        Pattern pattern = Pattern.compile(patternString);
        Matcher matcher = pattern.matcher(target);
        matcher.find();
        return matcher.group(1);
    }

    private final static String BASE_URL = "https://www.volkswagen-car-net.com";
    private final static String BASE_GUEST_URL = "/portal/en_GB/web/guest/home";

    private String getResponse(InputStream stream) throws Exception {

        BufferedReader in = new BufferedReader(new InputStreamReader(stream));
        String inputLine;
        StringBuffer responseStringBuffer = new StringBuffer();
        while ((inputLine = in.readLine()) != null) {
            responseStringBuffer.append(inputLine);
        }
        in.close();
        return responseStringBuffer.toString();
    }

    private String getResponse(HttpURLConnection connection) throws Exception {
        return getResponse(connection.getInputStream());
    }

    private void run() throws Exception {

        HttpURLConnection getConnection1;
        URL url = new URL(BASE_URL + BASE_GUEST_URL);
        getConnection1 = (HttpURLConnection) url.openConnection();
        getConnection1.setRequestMethod("GET");
        if (getConnection1.getResponseCode() != HttpURLConnection.HTTP_OK) {
            throw new Exception("Request failed");
        }

        String response = getResponse(getConnection1);
        getConnection1.disconnect();

        String csrf = extract("<meta name=\"_csrf\" content=\"(.*)\"/>", response);
        System.out.println(csrf);

        HttpURLConnection postRequest;
        URL url2 = new URL(BASE_URL + "/portal/web/guest/home/-/csrftokenhandling/get-login-url");
        postRequest = (HttpURLConnection) url2.openConnection();
        postRequest.setDoOutput(true);
        postRequest.setRequestMethod("POST");
        postRequest.setInstanceFollowRedirects(false);

        postRequest.setRequestProperty("Accept", "text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,image/apng,*/*;q=0.8");
        postRequest.setRequestProperty("User-Agent'", "Mozilla/5.0 (Linux; Android 6.0.1; D5803 Build/23.5.A.1.291; wv) AppleWebKit/537.36 (KHTML, like Gecko) Version/4.0 Chrome/63.0.3239.111 Mobile Safari/537.36");
        postRequest.setRequestProperty("Referer", BASE_URL + "/portal");
        postRequest.setRequestProperty("X-CSRF-Token", csrf);

        postRequest.disconnect();
    }

    public static void main(String[] args) throws Exception {

        MyApp myApp = new MyApp();
        myApp.run();
    }
}