Apache Kafka；kafka下载地址，一定不要下源码，不要下错，要下Binary downloads

kafka3.0之后内置zk所以不需要额外下载

第一步：配置文件修改

server.properties

# broker.id 要保持唯一，只启动一台的话则不需修改
# The id of the broker. This must be set to a unique integer for each broker.
broker.id=0
# 修改日志存放位置
# A comma separated list of directories under which to store log files
log.dirs=D://kafka//kafka_2.13-3.1.0//kafka-logs
# 修改zk连接地址，默认本机启动则不需要修改
# Zookeeper connection string (see zookeeper docs for details).
# This is a comma separated host:port pairs, each corresponding to a zk
# server. e.g. "127.0.0.1:3000,127.0.0.1:3001,127.0.0.1:3002".
# You can also append an optional chroot string to the urls to specify the
# root directory for all kafka znodes.
zookeeper.connect=localhost:2181

如果出现问题，还要添加一个参数：hostname:服务器的ip,(必须用IP连接）

zookeeper.properties

# 修改日志存放位置
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
# the directory where the snapshot is stored.
dataDir=D://kafka//kafka_2.13-3.1.0//zookeeper-logs

第二步：启动

要先启动zk
启动语句

.\bin\windows\zookeeper-server-start.bat .\config\zookeeper.properties

然后启动kafka
启动语句

.\bin\windows\kafka-server-start.bat .\config\server.properties

进入/bin/windows 目录下通过下面的命令创建topic

kafka-topics.bat --bootstrap-server localhost:9092 --create --replication-factor 3 --partitions 1 --topic test

查看当前有哪些topic

kafka-topics.bat --bootstrap-server localhost:9092 --list

查看某个topic的详细信息

kafka-topics.bat --bootstrap-server localhost:9092 --describe --topic test

修改topic的配置

kafka-topics.bat --bootstrap-server localhost:9092 --alter --topic test --partitions 3

删除topic会报错，此时停掉所有的cmd，然后将日志文件删除，重新启动可以解决

启动生产者命令/bin/window 目录下

kafka-console-producer.bat --broker-list localhost:9092 --topic test

启动消费者命令/bin/window 目录下

kafka-console-consumer.bat --bootstrap-server localhost:9092 --topic test --from-beginning

然后就可以快乐的发送啦！

Java代码：

maven添加配置

   <!--kafka依赖配置 *****开始******-->
        <dependency>
            <groupId>org.apache.kafka</groupId>
            <artifactId>kafka_2.12</artifactId>
            <version>2.1.1</version>
            <scope>provided</scope>
        </dependency>
        <!-- https://mvnrepository.com/artifact/org.apache.kafka/kafka-clients -->
        <dependency>
            <groupId>org.apache.kafka</groupId>
            <artifactId>kafka-clients</artifactId>
            <version>2.6.3</version>
        </dependency>
        <dependency>
            <groupId>org.apache.kafka</groupId>
            <artifactId>kafka-streams</artifactId>
            <version>1.0.0</version>
        </dependency>
        <dependency>
            <groupId>org.apache.commons</groupId>
            <artifactId>commons-lang3</artifactId>
            <version>3.12.0</version>
        </dependency>
        <!--kafka依赖配置 *****结束******-->

生产者代码：

import java.util.Properties;
import org.apache.kafka.clients.producer.KafkaProducer;
import org.apache.kafka.clients.producer.ProducerRecord;
import org.apache.kafka.common.serialization.StringSerializer;


public class KafkaProducerTest implements Runnable {

    private final KafkaProducer<String, String> producer;
    private final String topic;
    private String clientid;
    public KafkaProducerTest(String topicName,String clientid) {
        Properties props = new Properties();
        props.put("bootstrap.servers", "192.168.0.108:9092");
        props.put("acks", "all");
        props.put("retries", 0);
        props.put("batch.size", 16384);
        props.put("key.serializer", StringSerializer.class.getName());
        props.put("value.serializer", StringSerializer.class.getName());
        this.producer = new KafkaProducer<String, String>(props);
        this.topic = topicName;
        this.clientid = clientid;
    }

    @Override
    public void run() {
        int messageNo = 1;
        try {
            for(;;) {
                String messageStr= "你好，这是第"+messageNo+"条数据 clientid=" + clientid;
                producer.send(new ProducerRecord<String, String>(topic, "Message", messageStr));
                //生产了100条就打印
                if(messageNo%100==0){
                    System.out.println("发送的信息:" + messageStr);
                }
                //生产1000条就退出
                if(messageNo == 1000){
                    System.out.println("成功发送了"+messageNo+"条");
                    break;
                }
                messageNo++;
            }
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            producer.close();
        }
    }

    public static void main(String args[]) {
        KafkaProducerTest test1 = new KafkaProducerTest("test", "clientid1");
        Thread thread1 = new Thread(test1);
        thread1.start();
    }
}

消费者代码：

import java.util.Arrays;
import java.util.Properties;
import org.apache.kafka.clients.consumer.ConsumerRecord;
import org.apache.kafka.clients.consumer.ConsumerRecords;
import org.apache.kafka.clients.consumer.KafkaConsumer;
import org.apache.kafka.common.serialization.StringDeserializer;


public class KafkaConsumerTest implements Runnable {

    private final KafkaConsumer<String, String> consumer;
    private ConsumerRecords<String, String> msgList;
    private final String topic;
    private String clientid;
    private static final String GROUPID = "groupA";

    public KafkaConsumerTest(String topicName,String clientid) {

        Properties props = new Properties();
        props.put("bootstrap.servers", "192.168.0.108:9092");
        props.put("group.id", GROUPID);
        props.put("enable.auto.commit", "true");
        props.put("auto.commit.interval.ms", "1000");
        props.put("session.timeout.ms", "30000");
        props.put("auto.offset.reset", "earliest");
        props.put("key.deserializer", StringDeserializer.class.getName());
        props.put("value.deserializer", StringDeserializer.class.getName());
        this.consumer = new KafkaConsumer<String, String>(props);
        this.topic = topicName;
        this.consumer.subscribe(Arrays.asList(topic));
        this.clientid = clientid;
    }

    @Override
    public void run() {
        int messageNo = 1;
        System.out.println("---------开始消费---------");
        try {
            for (;;) {
                msgList = consumer.poll(1000);
                if(null!=msgList&&msgList.count()>0){
                    for (ConsumerRecord<String, String> record : msgList) {
                        //消费100条就打印 ,但打印的数据不一定是这个规律的
                        if(messageNo%100==0){
                            System.out.println(messageNo+"=======成功消费：receive: key = " + record.key() + ", value = " + record.value()+" offset==="+record.offset());
                        }
                        //当消费了1000条就退出
                        if(messageNo == 1000){
                            break;
                        }
                        messageNo++;
                    }
                }else{
                    Thread.sleep(1000);
                }
            }
        } catch (InterruptedException e) {
            e.printStackTrace();
        } finally {
            consumer.close();
        }
    }

    public static void main(String args[]) {
        KafkaConsumerTest test1 = new KafkaConsumerTest("test", "clientid1");
        Thread thread1 = new Thread(test1);
        thread1.start();
    }
}

自测没问题！