2023年8月

sleep一段时间

var sleep = async function (ms) {
            return new Promise(function (resolve) {
                setTimeout(resolve, ms);
            });
        };

使用

for (var i = 0; i < 10; i++) {
            console.log(i, Date.now());
            await sleep(2000);
        }

安装kafka-python

pip install kafka-python

代码

from kafka import KafkaConsumer, TopicPartition

bootstrap_servers = ['localhost:9092']
topic = 'test'
group_id = 'lll'

consumer = KafkaConsumer(
    group_id="my-group",
    bootstrap_servers=bootstrap_servers,
    auto_offset_reset='latest'
)

PARTITIONS = []
for partition in consumer.partitions_for_topic(topic):
    PARTITIONS.append(TopicPartition(topic, partition))

end_offsets = consumer.end_offsets(PARTITIONS)
print(end_offsets)

#输出
#{TopicPartition(topic='test', partition=2): 354915,
#TopicPartition(topic='test', partition=1): 354926,
#TopicPartition(topic='test', partition=0): 354892}

安装kafka库

pip3 install kafka-python

代码

from kafka import KafkaProducer,KafkaConsumer,KafkaAdminClient
import json
import time
topic = 'number'
bootstrap_servers=['127.0.0.1:9092']

消费者

consumer = KafkaConsumer(topic,
                        group_id=group_id,
                         bootstrap_servers=bootstrap_servers)
for message in consumer:
    print ("value=%s" % (message.value))

生产者

producer = KafkaProducer(bootstrap_servers=bootstrap_servers)
for i in range(100):
    producer.send(topic, json.dumps({'number': i}).encode('utf-8'))
producer.flush()

topic增加分区

from kafka.admin import NewPartitions

admin_client = KafkaAdminClient(bootstrap_servers=bootstrap_servers)
topic_partitions = {}
topic_partitions[topic] = NewPartitions(total_count=5)
admin_client.create_partitions(topic_partitions)

列出所有消费者

from kafka import KafkaAdminClient


def list_consumer_groups(broker):
    admin_client = KafkaAdminClient(bootstrap_servers=broker)

    # List all the consumer groups
    groups = admin_client.list_consumer_groups()

    return [group[0] for group in groups]


broker_address = "localhost:9092"
print(list_consumer_groups(broker_address))

package com.journaldev.cloning;

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

public class Employee implements Cloneable {

    private int id;

    private String name;

    private Map<String, String> props;

    public int getId() {
        return id;
    }

    public void setId(int id) {
        this.id = id;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public Map<String, String> getProps() {
        return props;
    }

    public void setProps(Map<String, String> p) {
        this.props = p;
    }

     @Override
     public Object clone() throws CloneNotSupportedException {
     return super.clone();
     }

}
Employee a = new Employee()
Employee b = a.clone()
  1. 1
  2. 2