The system uses Spring Boot for backend services, WxPush for messaging, and xxl-job for distributed task scheduling.

Dependencies

<dependency>
    <groupId>com.lxgnb</groupId>
    <artifactId>xxl-job-boot-starter</artifactId>
    <version>2.4.0</version>
</dependency>
<dependency>
    <groupId>com.zjiecode</groupId>
    <artifactId>wxpusher-java-sdk</artifactId>
    <version>2.2.0</version>
</dependency>

Core Workflow

1. Create WxPush application with callback URL to capture user UIDs
2. Store UID-taskID mappings in data base
3. Trigger messsages via WxPush when xxl-job executes

Task Registration Logic

String[] inputSegments = rawInput.split(" ");
String schedulePattern = inputSegments[0];

// Validate cron syntax
if(!CronValidator.isValid(schedulePattern)) {
    PushMessage failureAlert = new PushMessage()
        .setType(MessageType.TEXT)
        .setTargetUser(uid)
        .setAppToken(appToken)
        .setBody("Invalid schedule pattern");
    WxPusher.send(failureAlert);
    return;
}

String alertContent = inputSegments[1];

JobConfiguration jobConfig = new JobConfiguration()
    .setContactEmail("admin@domain.com")
    .setOwner("scheduler")
    .setSummary("Class reminder")
    .setHandlerName("classAlertHandler")
    .setTriggerType(ScheduleMode.CRON)
    .setCronExpression(schedulePattern);

int generatedTaskId = jobManager.registerJob(jobConfig);
if(generatedTaskId > 0) {
    TaskMapping mapping = new TaskMapping()
        .setTaskIdentifier(generatedTaskId)
        .setUserId(uid)
        .setAlertText(alertContent);
    taskRepository.persist(mapping);
    jobManager.enableTask(generatedTaskId);
    
    PushMessage successNotice = new PushMessage()
        .setType(MessageType.TEXT)
        .setTargetUser(uid)
        .setAppToken(appToken)
        .setBody("Alert scheduled. Send DEL to cancel");
    WxPusher.send(successNotice);
}

Class Schedule Processing

• Python scraper collects institutional timetables weekly
• Database stores class schedules with week indices
• UID-class mappings determine notification recipients
• xxl-job executor checks mappings and triggers alerts when classes start

Scheduling Interface

Users submit cron expressions and alert messages. Future enhancement will integrate LLM-based cron generation from natural language requests.