如何用Java创建Kafka ZKStringSerializer？ [英] How create Kafka ZKStringSerializer in Java?

问题描述

在搜索如何通过API创建Kafka主题时，我在Scala中找到了这个示例：

In searching for how to create a Kafka topic through the API, I found this example in Scala:

import kafka.admin.AdminUtils
import kafka.utils.ZKStringSerializer
import org.I0Itec.zkclient.ZkClient

// Create a ZooKeeper client
val sessionTimeoutMs = 10000
val connectionTimeoutMs = 10000
val zkClient = new ZkClient("zookeeper1:2181", sessionTimeoutMs,
                            connectionTimeoutMs, ZKStringSerializer)

// Create a topic with 8 partitions and a replication factor of 3
val topicName = "myTopic"
val numPartitions = 8
val replicationFactor = 3
val topicConfig = new Properties
AdminUtils.createTopic(zkClient, topicName, 
                       numPartitions, replicationFactor, topicConfig)

来源：https://stackoverflow.com/a/23360100/871012

最后一个arg ZKStringSerializer 显然是一个Scala对象。我不清楚如何使这个例子在Java中工作。

The last arg ZKStringSerializer is apparently a Scala object. It is not clear to me how to make this example work in Java.

这篇文章如何在clojure中创建一个scala对象在Clojure中询问相同的问题，答案是：

This post How to create a scala object in clojure asks the same question in Clojure and the answer was:

ZKStringSerializer$/MODULE$

在Java中将（我认为）转换为：

which in Java would (I think) translate to:

ZKStringSerializer$.MODULE$

但当我尝试（或任何其他数量的变体）时，它们都没有编译。

编译错误是：

But when I try that (or any number of other variations) none of them compile.
The compilation error is:

KafkaTopicCreator.java:[16,18] cannot find symbol
symbol:   variable ZKStringSerializer$
location: class org.sample.KafkaTopicCreator

我使用的是kafka_2.9.2-0.8.1.1和Java 8.

I am using kafka_2.9.2-0.8.1.1 and Java 8.

推荐答案

对于java，请尝试以下方法，

For java try the following,

首先导入以下语句

import kafka.utils.ZKStringSerializer$;

按以下方式为ZkClient创建对象，

Create object for ZkClient in the following way,

String zkHosts = "127.0.0.1:2181"; //If more than one zookeeper then "127.0.0.1:2181,127.0.0.2:2181"
ZkClient zkClient = new ZkClient(zkHosts, 10000, 10000, ZKStringSerializer$.MODULE$);
AdminUtils.createTopic(zkClient, myTopic, 10, 1, new Properties());

---

---

上述代码对于kafka> 0.9不起作用，因为api已被更改，
使用以下代码为kafka> 0.9

The above code won't work for kafka > 0.9 since the api has been changed, Use the below code for kafka > 0.9

import java.util.Properties;
import kafka.admin.AdminUtils;
import kafka.utils.ZKStringSerializer$;
import kafka.utils.ZkUtils;
import org.I0Itec.zkclient.ZkClient;
import org.I0Itec.zkclient.ZkConnection;

public class KafkaTopicCreationInJava
{
    public static void main(String[] args) throws Exception {
        ZkClient zkClient = null;
        ZkUtils zkUtils = null;
        try {
            String zookeeperHosts = "192.168.20.1:2181"; // If multiple zookeeper then -> String zookeeperHosts = "192.168.20.1:2181,192.168.20.2:2181";
            int sessionTimeOutInMs = 15 * 1000; // 15 secs
            int connectionTimeOutInMs = 10 * 1000; // 10 secs

            zkClient = new ZkClient(zookeeperHosts, sessionTimeOutInMs, connectionTimeOutInMs, ZKStringSerializer$.MODULE$);
            zkUtils = new ZkUtils(zkClient, new ZkConnection(zookeeperHosts), false);

            String topicName = "testTopic";
            int noOfPartitions = 2;
            int noOfReplication = 3;
            Properties topicConfiguration = new Properties();

            AdminUtils.createTopic(zkUtils, topicName, noOfPartitions, noOfReplication, topicConfiguration);

        } catch (Exception ex) {
            ex.printStackTrace();
        } finally {
            if (zkClient != null) {
                zkClient.close();
            }
        }
    }
}

这篇关于如何用Java创建Kafka ZKStringSerializer？的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！