无法写入MongoDB

Question

首先，我启动了zookeeper，然后启动了kafka服务器，并创建了一个主题。然后，我阅读了tweet并尝试将它们存储到MongoDB中，尽管服务器正在建立连接，但没有任何内容写入我的收藏夹。

这是Java代码：

package kafka;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;
import java.util.Properties;
import java.util.concurrent.LinkedBlockingQueue;

import twitter4j.*;
import twitter4j.StallWarning;
import twitter4j.Status;
import twitter4j.StatusDeletionNotice;
import twitter4j.StatusListener;
import twitter4j.TwitterStream;
import twitter4j.TwitterStreamFactory;
import twitter4j.conf.ConfigurationBuilder;

import org.apache.kafka.clients.producer.Producer;
import org.apache.kafka.clients.producer.KafkaProducer;
import org.apache.kafka.clients.producer.ProducerRecord;
import org.apache.log4j.Logger;
import org.bson.Document;
import org.mortbay.util.ajax.JSON;

import com.mongodb.*;
import com.mongodb.client.MongoCollection;
import com.mongodb.client.MongoDatabase;

public class KafkaTwitterProducer {
    @SuppressWarnings("resource")
    public static void main(String[] args) throws Exception {
        final LinkedBlockingQueue<Status> queue = new LinkedBlockingQueue<Status>(1000);

        if (args.length < 4) {
            System.out.println(
                    "Usage: KafkaTwitterProducer <twitter-consumer-key> <twitter-consumer-secret> <twitter-access-token> <twitter-access-token-secret> <topic-name> <twitter-search-keywords>");
            return;
        }

        String consumerKey = args[0].toString();
        String consumerSecret = args[1].toString();
        String accessToken = args[2].toString();
        String accessTokenSecret = args[3].toString();
        String topicName = args[4].toString();
        String[] arguments = args.clone();
        String[] keyWords = Arrays.copyOfRange(arguments, 5, arguments.length);

        // Set twitter oAuth tokens in the configuration
        ConfigurationBuilder cb = new ConfigurationBuilder();
        cb.setDebugEnabled(true).setOAuthConsumerKey(consumerKey).setOAuthConsumerSecret(consumerSecret)
                .setOAuthAccessToken(accessToken).setOAuthAccessTokenSecret(accessTokenSecret).setJSONStoreEnabled(true);

        // Create twitterstream using the configuration
        TwitterStream twitterStream = new TwitterStreamFactory(cb.build()).getInstance();
        StatusListener listener = new StatusListener() {

            public void onStatus(Status status) {
                queue.offer(status);
            }

            public void onDeletionNotice(StatusDeletionNotice statusDeletionNotice) {
                System.out.println("Got a status deletion notice id:" + statusDeletionNotice.getStatusId());
            }

            public void onTrackLimitationNotice(int numberOfLimitedStatuses) {
                System.out.println("Got track limitation notice:" + numberOfLimitedStatuses);
            }

            public void onScrubGeo(long userId, long upToStatusId) {
                System.out.println("Got scrub_geo event userId:" + userId + "upToStatusId:" + upToStatusId);
            }

            public void onStallWarning(StallWarning warning) {
                System.out.println("Got stall warning:" + warning);
            }

            public void onException(Exception ex) {
                ex.printStackTrace();
            }
        };
        twitterStream.addListener(listener);

        // Filter keywords
        FilterQuery query = new FilterQuery().track(keyWords);
        twitterStream.filter(query);

        // Thread.sleep(5000);

        // Add Kafka producer config settings
        Properties props = new Properties();
        props.put("metadata.broker.list", "localhost:9092");
        props.put("bootstrap.servers", "localhost:9092");
        props.put("acks", "all");
        props.put("retries", 0);
        props.put("batch.size", 16384);
        props.put("linger.ms", 1);
        props.put("buffer.memory", 33554432);

        props.put("key.serializer", "org.apache.kafka.common.serialization.StringSerializer");
        props.put("value.serializer", "org.apache.kafka.common.serialization.StringSerializer");

        Producer<String, String> producer = new KafkaProducer<String, String>(props);
        int i = 0;
        int j = 0;

        // Mongodb initialization parameters.
        int port_no = 27017;
        String host_name = "localhost", db_name = "bigdata", db_coll_name = "tweets";

        // Mongodb connection string.
        String client_url = "mongodb://" + host_name + ":" + port_no + "/" + db_name;
        MongoClientURI uri = new MongoClientURI(client_url);

        // Connecting to the mongodb server using the given client uri.
        MongoClient mongo_client = new MongoClient(uri);

        // Fetching the database from the mongodb.
        MongoDatabase db = mongo_client.getDatabase(db_name);

        // Fetching the collection from the mongodb.
        MongoCollection<Document> coll = db.getCollection(db_coll_name);

        //List<Document> docs = new ArrayList<Document>();


        // poll for new tweets in the queue. If new tweets are added, send them
        // to the topic
        for(Status status:queue) {
             String json = TwitterObjectFactory.getRawJSON(status);
             BasicDBObject dbObject = (BasicDBObject) JSON.parse(json);
             coll.insertOne(new Document(dbObject));
        }
    }

}

这是mongod命令提示符向我显示的内容：

2019-05-26T19:26:29.181+0300 I NETWORK  [initandlisten] waiting for connections on port 27017
2019-05-26T19:28:05.466+0300 I NETWORK  [listener] connection accepted from 127.0.0.1:54232 #1 (1 connection now open)
2019-05-26T19:28:05.475+0300 I NETWORK  [conn1] received client metadata from 127.0.0.1:54232 conn1: { driver: { name: "mongo-java-driver", version: "3.5.0" }, os: { type: "Windows", name: "Windows 10", architecture: "amd64", version: "10.0" }, platform: "Java/Oracle Corporation/1.8.0_152-b16" }

，但不向数据库写入任何推文。有人可以解释错误在哪里吗？