93 lines
3.3 KiB
Java
93 lines
3.3 KiB
Java
package com.guwan.backend.handler;
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import com.fasterxml.jackson.databind.JsonNode;
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import com.fasterxml.jackson.databind.ObjectMapper;
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import com.guwan.backend.service.CourseService;
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import lombok.extern.slf4j.Slf4j;
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import org.springframework.beans.factory.annotation.Autowired;
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import org.springframework.stereotype.Component;
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import org.springframework.web.socket.CloseStatus;
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import org.springframework.web.socket.TextMessage;
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import org.springframework.web.socket.WebSocketSession;
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import org.springframework.web.socket.handler.TextWebSocketHandler;
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import java.io.IOException;
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import java.util.Map;
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import java.util.Set;
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import java.util.concurrent.ConcurrentHashMap;
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@Slf4j
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@Component
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public class CoursesWebSocketHandler extends TextWebSocketHandler {
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@Autowired
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private CourseService courseService;
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private static final Set<WebSocketSession> sessions = ConcurrentHashMap.newKeySet();
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@Override
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public void afterConnectionEstablished(WebSocketSession session) {
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log.info("Home page WebSocket connection established: {}", session.getId());
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sessions.add(session);
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// 连接建立时，发送所有课程的当前学习人数
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sendAllCourseCounts(session);
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}
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@Override
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protected void handleTextMessage(WebSocketSession session, TextMessage message) {
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log.info("Home page received message from {}: {}", session.getId(), message.getPayload());
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try {
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JsonNode jsonNode = new ObjectMapper().readTree(message.getPayload());
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String type = jsonNode.get("type").asText();
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if ("STUDENT_COUNT_UPDATE".equals(type)) {
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// 转发消息给所有首页连接的客户端
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broadcastMessage(message.getPayload());
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}
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} catch (Exception e) {
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log.error("Error handling home page message", e);
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}
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}
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@Override
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public void afterConnectionClosed(WebSocketSession session, CloseStatus status) {
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log.info("Home page WebSocket connection closed: {}, status: {}", session.getId(), status);
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sessions.remove(session);
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}
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public void broadcastMessage(String message) {
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sessions.forEach(session -> {
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try {
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if (session.isOpen()) {
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session.sendMessage(new TextMessage(message));
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}
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} catch (IOException e) {
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log.error("Error broadcasting to home page", e);
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}
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});
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}
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private void sendAllCourseCounts(WebSocketSession session) {
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try {
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// 获取所有课程的学习人数
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Map<String, Integer> allCounts = courseService.getAllCourseCounts();
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// 发送每个课程的学习人数
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allCounts.forEach((courseId, count) -> {
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String message = String.format(
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"{\"type\":\"STUDENT_COUNT_UPDATE\",\"courseId\":\"%s\",\"count\":%d}",
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courseId, count
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);
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try {
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if (session.isOpen()) {
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session.sendMessage(new TextMessage(message));
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}
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} catch (IOException e) {
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log.error("Error sending course count", e);
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}
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});
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} catch (Exception e) {
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log.error("Error sending all course counts", e);
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}
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}
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} |