Java CookieManager为什么获取不到cookie，我获取响应头的时候能看到set-cookie这个头部呀

Question

题目描述

题目来源及自己的思路

相关代码

// 请把代码文本粘贴到下方（请勿用图片代替代码）
URL url = new URL("HTTP://km.oa.com");

    HttpURLConnection con = (HttpURLConnection) url.openConnection();
    con.setInstanceFollowRedirects(false);
    CookieManager manager = new CookieManager();
    manager.setCookiePolicy(CookiePolicy.ACCEPT_ALL);
    CookieHandler.setDefault(manager);
    
    con.getInputStream();
    System.out.println(con.getResponseCode());
    CookieStore store = manager.getCookieStore();
    List<HttpCookie> cookie = store.getCookies();
    System.out.println(cookie);
    for (HttpCookie coo : cookie) {
        System.out.println(coo);
    }
    String str = con.getHeaderField("set-cookie");
    System.out.println(str);

你期待的结果是什么？实际看到的错误信息又是什么？

Answer 1

需要在

manager.getCookieStore();之前再做一次openConnection();和getInputStream();
也可以考虑用HttpClient获取cookie
CookieStore cookieStore = new BasicCookieStore();
httpClient = HttpClients.custom().setDefaultCookieStore(cookieStore).build();
List<Cookie> cookies = cookieStore.getCookies();