Kafka消费者 从Kafka中读取数据并写入文件

Kafka消费者 从Kafka中读取数据

最近有需求要从kafak上消费读取实时数据，并将数据中的key输出到文件中，用于发布端的原始点进行比对，以此来确定是否传输过程中有遗漏数据。

不废话，直接上代码，公司架构设计 kafak 上有多个TOPIC，此代码每次需要指定一个TOPIC，一个TOPIC有3个分区Partition，所以消费的时候用多线程，

读取数据过程中直接过滤重复的key点，因为原始推送点有20W的量(可能发生在一秒或者几秒)。当时我直接用的HASHMAP来过滤。

1、ConsumerGroup 

import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;

public class ConsumerGroup {
    private List<ConsumerRunnable> consumers;

    public ConsumerGroup(int consumerNum, String groupId, String topic, String brokerList,HashMap<String,String> points) {
        consumers = new ArrayList<>(consumerNum);
        for (int i = 0; i < consumerNum; ++i) {
            ConsumerRunnable consumerThread = new ConsumerRunnable(brokerList, groupId, topic, points);
            consumers.add(consumerThread);
        }
    }

    public void execute() {
        for (ConsumerRunnable task : consumers) {
            new Thread(task).start();
        }
    }
}

2、ConsumerRunnable

import com.google.gson.JsonArray;
import com.google.gson.JsonObject;
import com.google.gson.JsonParser;
import org.apache.kafka.clients.consumer.ConsumerRecord;
import org.apache.kafka.clients.consumer.ConsumerRecords;
import org.apache.kafka.clients.consumer.KafkaConsumer;

import java.util.Arrays;
import java.util.HashMap;
import java.util.Properties;

public class ConsumerRunnable implements Runnable {

    // 每个线程维护私有的KafkaConsumer实例
    private final KafkaConsumer<String, String> consumer;

    HashMap<String,String> points = new HashMap<>();

    public ConsumerRunnable(String brokerList, String groupId, String topic,HashMap<String,String> nodepoint) {
        Properties props = new Properties();
        props.put("bootstrap.servers", brokerList);
        props.put("group.id", groupId);
        props.put("enable.auto.commit", "true");        //本例使用自动提交位移
        props.put("auto.commit.interval.ms", "1000");
        props.put("session.timeout.ms", "30000");
        props.put("key.deserializer", "org.apache.kafka.common.serialization.StringDeserializer");
        props.put("value.deserializer", "org.apache.kafka.common.serialization.StringDeserializer");
        this.consumer = new KafkaConsumer<>(props);
        consumer.subscribe(Arrays.asList(topic));   // 本例使用分区副本自动分配策略
        points = nodepoint;
    }

    @Override
    public void run() {
        while (true) {
            ConsumerRecords<String, String> records = consumer.poll(200);
            for (ConsumerRecord<String, String> record : records) {
//                System.out.printf("Partition = %s , offset = %d, key = %s, value=%s",record.partition(),record.offset(),record.key(),record.value());

                JsonParser parse = new JsonParser();
                JsonObject jsonObject = (JsonObject) parse.parse(record.value());
                JsonArray jsonArray = jsonObject.get("list").getAsJsonArray();
                for (int i=0 ;i <jsonArray.size();i++){
                    JsonObject subject = jsonArray.get(i).getAsJsonObject();
                    String cedian = subject.get("id").getAsString().trim();
                    if(points.containsKey(cedian) == false){
                        points.put(cedian,cedian);
                        WriterDataFile.writeData(cedian);
                    }

//                    System.out.println(subject.get("id").getAsString());
                }
            }
        }
    }
}

3、ConsumerTest 

import java.util.HashMap;

public class ConsumerTest {



    public static void main(String[] args) {
        String brokerList = "172.16.10.22:9092,172.16.10.23:9092,172.16.10.21:9092";
        String groupId = "test20190722";
        String topic = "SDFD";
        int consumerNum = 3;

        HashMap<String,String> points = new HashMap<>();

        ConsumerGroup consumerGroup = new ConsumerGroup(consumerNum, groupId, topic, brokerList,points);
        consumerGroup.execute();




    }
}

4、WriterDataFile

import java.io.*;
import java.util.HashMap;

public class WriterDataFile {

   private static String path = "E:\kafkadata_SDFD.txt";

    public static void writeData(String strvalue){
        FileWriter fw ;
        try {
            fw = new FileWriter(path,true);
            BufferedWriter bw = new BufferedWriter(fw);
            bw.write(strvalue+"
");
            bw.flush();
            bw.close();
            fw.close();
        } catch (IOException e) {
            e.printStackTrace();
        }

    }

}

都是基础写法，没有时间整理，如有不合理处请谅解。

码字不易...