kafak消费数据，webSocket实时推送数据到前端

1.导入webSocket依赖

 
        
            org.springframework.boot
            spring-boot-starter-websocket
        

2.编写webSocket类

package com.skyable.device.config.webSocket;


import lombok.extern.slf4j.Slf4j;
import org.springframework.stereotype.Component;

import javax.websocket.OnClose;
import javax.websocket.OnError;
import javax.websocket.OnOpen;
import javax.websocket.Session;
import javax.websocket.server.ServerEndpoint;
import java.io.IOException;
import java.util.HashSet;
import java.util.Set;

/**
 * @author Administrator
 */
@ServerEndpoint("/vehicle/{domainId}")
@Component
@Slf4j
public class WebSocketServer {
    /**
     * concurrent包的线程安全Set，用来存放每个客户端对应的MyWebSocket对象。
     */
    private static final Set SESSIONS = new HashSet<>();


    /**
     * 连接关闭调用的方法
     */
    @OnClose
    public void onClose() {
        log.info("webSocket link close");
    }

    /**
     * @param error
     */
    @OnError
    public void onError(Throwable error) {
        error.printStackTrace();
    }

    /**
     * 接收数据
     *
     * @param data
     */
    public static void sendDataToClients(String data) {
        for (Session session : SESSIONS) {
            try {
                session.getBasicRemote().sendText(data);
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
    }

    @OnOpen
    public void onOpen(Session session) {
        /**
         * 与某个客户端的连接会话，需要通过它来给客户端发送数据
         */
        /**
         * 接收domainId
         */
        SESSIONS.add(session);
        sendDataToClients();
    }


    public void sendDataToClients() {
        for (Session session : SESSIONS) {
            try {
                session.getBasicRemote().sendText("webSocket link succeed");
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
    }
}

package com.skyable.device.config.webSocket;

import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.web.socket.config.annotation.EnableWebSocket;
import org.springframework.web.socket.server.standard.ServerEndpointExporter;

/**
 * @author Administrator
 */
@EnableWebSocket
@Configuration
public class WebSocketConfig {
    @Bean
    public ServerEndpointExporter serverEndpointExporter() {
        return new ServerEndpointExporter();
    }
}

3.kafak消费数据后调用webSocket方法

  /**
     * 获取kafka数据
     *
     * @param
     */
    @Override
    public void saveBatch(String jsonValue) {
        ObjectMapper objectMapper = new ObjectMapper();
        try {
            //位置
            JsonNode jsonNode = objectMapper.readTree(jsonValue);
            if (jsonNode.has(VehicleConstant.LOCATION)) {
                RealTimePosition realTimePosition = new RealTimePosition();
                JsonNode locationNode = jsonNode.get("location");
                String vehicleId = locationNode.get("vehicleId").asText();
                double longitude = Double.parseDouble(locationNode.get("longitude").asText());
                double latitude = Double.parseDouble(locationNode.get("latitude").asText());
                long timeStamp = locationNode.get("timestamp").asLong();
                realTimePosition.setTimeStamp(timeStamp);
                realTimePosition.setLatitude(String.valueOf(latitude));
                realTimePosition.setLongitude(String.valueOf(longitude));
                realTimePosition.setVehicleId(vehicleId);
                VehicleLocationVo locationVo = deviceMapMapper.selectLonLat(vehicleId);
                if (!Objects.isNull(locationVo)) {
                    //计算距离
                    RedisUtil.addLocation(vehicleId, Double.parseDouble(locationVo.getLongitude()), Double.parseDouble(locationVo.getLatitude()), "l1");
                    RedisUtil.addLocation(vehicleId, longitude, latitude, "l2");
                    Double result = RedisUtil.calculateDistance(vehicleId, "l1", "l2");
                    Double meters = RedisUtil.convertMilesToKilometers(result);
                    DecimalFormat decimalFormat = new DecimalFormat("#.###");
                    String distance = decimalFormat.format(meters);
                    realTimePosition.setDistance(Double.parseDouble(distance));
                } else {
                    realTimePosition.setDistance(0);
                }
                //获取省份
                Map position = addressUtil.getPosition(longitude, latitude, null, null, null);
                Map data = (Map) position.get("data");
                String provinceName = data.get("shortname").toString().replaceAll("\"", "");
                realTimePosition.setArea(provinceName);
                deviceMapMapper.insertRealTimePosition(realTimePosition);
                RedisUtil.addZSetValue(VehicleConstant.VEHICLE_LOCATION, String.valueOf(vehicleId), timeStamp);
            }
        } catch (JsonProcessingException e) {
            e.printStackTrace();
        }
        try {
            //报警
            JsonNode jsonNode = objectMapper.readTree(jsonValue);
            if (jsonNode.has(VehicleConstant.ALERT)) {
                JsonNode alertNode = jsonNode.get("alert");
                String vehicleId = alertNode.get("vehicleId").asText();
                Integer alertType = alertNode.get("alertType").asInt();
                long timeStamp = alertNode.get("timestamp").asLong();
                Alerts alerts = new Alerts();
                alerts.setAlertType(alertType);
                alerts.setTimeStamp(timeStamp);
                alerts.setVehicleId(vehicleId);
                deviceMapMapper.insertAlerts(alerts);
                RedisUtil.addZSetValue(VehicleConstant.VEHICLE_ALERT, String.valueOf(vehicleId), timeStamp);
            }
        } catch (JsonProcessingException e) {
            e.printStackTrace();
        }
        //webSocket发送消息
        VehicleAllVo vehicles = vehicles();
        WebSocketServer.sendDataToClients(vehicles.toString());
    }

4.发送消息内容

VehicleAllVo vehicles = vehicles();
该方法就是发送的具体内容

5.kafak消费者

package com.skyable.device.listener.Vehicle;

import com.alibaba.fastjson.JSON;
import com.skyable.common.config.CloudApplicationContext;
import com.skyable.common.constants.kafka.KafkaTopicConstants;
import com.skyable.device.config.webSocket.WebSocketServer;
import com.skyable.device.entity.vehicle.Vehicle;
import com.skyable.device.service.DeviceMapService;
import lombok.RequiredArgsConstructor;
import lombok.extern.slf4j.Slf4j;
import org.apache.kafka.clients.consumer.ConsumerRecord;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.kafka.annotation.KafkaListener;
import org.springframework.kafka.core.KafkaTemplate;
import org.springframework.stereotype.Component;
import org.springframework.stereotype.Service;

import java.util.List;
import java.util.stream.Collectors;

/**
 * Description:
 *
 * @author yangJun
 * @date: 2023-08-18-14:12
 */
@Service
@Component
@Slf4j
@RequiredArgsConstructor(onConstructor = @__(@Autowired))
public class VehicleDataKafkaListener {
    private final DeviceMapService deviceMapService;

    @KafkaListener(topics = KafkaTopicConstants.TOPIC_VEHICLE_RECORD, groupId = "rx_1_thing", containerFactory = "batchFactory")
    public void dealDeviceDataToScript(List> recordList) {
        recordList.parallelStream()
                .map(ConsumerRecord::value)
                .forEach(this::saveVehicleData);
    }

    private void saveVehicleData(String jsonValue) {
        log.info("kafka data:" + jsonValue);
        deviceMapService.saveBatch(jsonValue);
    }
}

package com.skyable.device.listener.Vehicle;

import org.apache.kafka.clients.consumer.ConsumerConfig;
import org.apache.kafka.clients.producer.ProducerConfig;
import org.apache.kafka.common.serialization.StringDeserializer;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.kafka.config.ConcurrentKafkaListenerContainerFactory;
import org.springframework.kafka.config.KafkaListenerContainerFactory;
import org.springframework.kafka.core.DefaultKafkaConsumerFactory;

import java.util.HashMap;
import java.util.Map;

/**
 * @ClassName KafkaConsumerConfig
 * @Description Kafka消费者配置
 * @Author gaoy
 * @Date 2021/2/25 15:02
 */
@Configuration
public class KafkaConfig {

    @Value("${spring.kafka.bootstrap-servers}")
    private String servers;

    @Value("${spring.kafka.consumer.enable-auto-commit}")
    private boolean enableAutoCommit;

    @Value("${spring.kafka.consumer.group-id}")
    private String groupId;

    @Value("${spring.kafka.consumer.auto-offset-reset}")
    private String autoOffsetReset;

    @Value("${spring.kafka.consumer.concurrency}")
    private int concurrency;

    @Value("${spring.kafka.consumer.max-poll-records}")
    private int maxPollRecords;


    /**
     * 批量消费工厂bean
     * @return
     */
    @Bean
    KafkaListenerContainerFactory batchFactory() {
        ConcurrentKafkaListenerContainerFactory factory = new
                ConcurrentKafkaListenerContainerFactory<>();
        factory.setConsumerFactory(new DefaultKafkaConsumerFactory<>(consumerConfigs()));
        // 开启批量监听
        factory.setBatchListener(true);
        factory.setConcurrency(concurrency);
        // 设置手动提交ackMode
        // factory.getContainerProperties().setAckMode(ContainerProperties.AckMode.MANUAL_IMMEDIATE);
        return factory;
    }

    @Bean
    public Map consumerConfigs() {
        Map props = new HashMap<>();
        props.put(ConsumerConfig.GROUP_ID_CONFIG, groupId);
        props.put(ConsumerConfig.AUTO_OFFSET_RESET_CONFIG, autoOffsetReset);
        props.put(ConsumerConfig.BOOTSTRAP_SERVERS_CONFIG, servers);
        props.put(ConsumerConfig.ENABLE_AUTO_COMMIT_CONFIG, enableAutoCommit);
        //设置每次接收Message的数量
        props.put(ConsumerConfig.MAX_POLL_RECORDS_CONFIG, maxPollRecords);
        props.put(ConsumerConfig.AUTO_COMMIT_INTERVAL_MS_CONFIG, "100");
        props.put(ConsumerConfig.SESSION_TIMEOUT_MS_CONFIG, 120000);
        props.put(ConsumerConfig.REQUEST_TIMEOUT_MS_CONFIG, 180000);
        props.put(ConsumerConfig.KEY_DESERIALIZER_CLASS_CONFIG, StringDeserializer.class);
        props.put(ConsumerConfig.VALUE_DESERIALIZER_CLASS_CONFIG, StringDeserializer.class);
        //开启幂等性。
        props.put(ProducerConfig.ENABLE_IDEMPOTENCE_CONFIG,true);
        return props;
    }

}