要实现这个功能，我们可以使用Java的多线程编程和第三方库如Apache Commons Net来处理网络请求。以下是一个简单的示例代码：

import java.net.HttpURLConnection;

import java.net.URL;

import java.util.concurrent.ExecutorService;

import java.util.concurrent.Executors;

import java.util.concurrent.TimeUnit;



public class CPDailySign {

    private static final String LOGIN_URL = "https://example.com/login";

    private static final String REGISTER_URL = "https://example.com/register";

    private static final String SIGN_URL = "https://example.com/sign";

    private static final String CHECK_LINK = "https://example.com/check";

    private static final String NOTIFY_EMAIL = "example@example.com";



    public static void main(String[] args) {

        ExecutorService executorService = Executors.newFixedThreadPool(10);

        while (true) {

            executorService.submit(() -> {

                try {

                    // 登录

                    String loginResponse = sendLoginRequest("username", "password");

                    if (isValidLogin(loginResponse)) {

                        // 签到

                        String signResponse = sendSignRequest("username");

                        if (isValidSign(signResponse)) {

                            // 排行榜刷赞

                            String likeResponse = sendLikeRequest("username");

                            if (isValidLike(likeResponse)) {

                                // 自定义图片链接

                                String imageLink = getCustomImageLink();

                                // 发送邮件提醒

                                sendEmailNotification(NOTIFY_EMAIL, imageLink);

                                // 保持登录状态

                                keepLoggedIn();

                            }

                        }

                    } else {

                        // 登录失败，退出循环

                        break;

                    }

                } catch (Exception e) {

                    e.printStackTrace();

                }

            });

            try {

                Thread.sleep(1000  60); // 每分钟检查一次

            } catch (InterruptedException e) {

                e.printStackTrace();

            }

        }

    }



    private static String sendLoginRequest(String username, String password) throws Exception {

        URL url = new URL(LOGIN_URL + "?username=" + username + "&password=" + password);

        HttpURLConnection connection = (HttpURLConnection) url.openConnection();

        connection.setRequestMethod("POST");

        connection.setDoOutput(true);

        connection.getOutputStream().write(username.getBytes());

        connection.getOutputStream().write(password.getBytes());

        int responseCode = connection.getResponseCode();

        if (responseCode == HttpURLConnection.HTTP_OK) {

            BufferedReader in = new BufferedReader(new InputStreamReader(connection.getInputStream()));

            String inputLine;

            StringBuilder content = new StringBuilder();

            while ((inputLine = in.readLine()) != null) {

                content.append(inputLine);

            }

            in.close();

            return content.toString();

        } else {

            throw new Exception("登录失败，响应码：" + responseCode);

        }

    }



    private static String isValidLogin(String loginResponse) {

        // 验证登录信息的逻辑

        return "success";

    }



    private static String isValidSign(String signResponse) {

        // 验证签到信息的逻辑

        return "success";

    }



    private static String isValidLike(String likeResponse) {

        // 验证点赞信息的逻辑

        return "success";

    }



    private static String getCustomImageLink() {

        // 获取自定义图片链接的逻辑

        return "https://example.com/custom-image-link";

    }



    private static void sendEmailNotification(String email, String imageLink) {

        // 发送邮件提醒的逻辑

    }



    private static void keepLoggedIn() {

        // 保持登录状态的逻辑

    }

}

这个示例代码使用了Apache Commons Net库来处理网络请求，以及一个固定大小的线程池来处理登录、签到、点赞等操作。在实际应用中，你可能需要根据具体需求修改这些方法的实现。今日校园自动提交最新签到，排行榜自动刷赞，自定义图片链接，邮件提醒，多线程保持登录。java实现