|NO.Z.00010|——————————|BigDataEnd|——|Hadoop&kafka.V10|——|kafka.v10|生产与消费.v05|模拟消息推送偏移量|
一、消费者实验代码
### --- [kafka架构与实战]
~~~ [kakfa开发实战_消息发送]
~~~ [kafka开发实战_消息消费]
~~~ [kafka开发实战_消息推送偏移量]### --- 消费者：MyProducer2
package com.yanqi.kafka.demo.producer;
import org.apache.kafka.clients.producer.Callback;
import org.apache.kafka.clients.producer.KafkaProducer;
import org.apache.kafka.clients.producer.ProducerRecord;
import org.apache.kafka.clients.producer.RecordMetadata;
import org.apache.kafka.common.header.Header;
import org.apache.kafka.common.header.internals.RecordHeader;
import org.apache.kafka.common.serialization.IntegerSerializer;
import org.apache.kafka.common.serialization.StringSerializer;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.concurrent.ExecutionException;
public class MyProducer2 {
public static void main(String[] args) throws ExecutionException, InterruptedException {
Map<String, Object> configs = new HashMap<>();
// 指定初始连接用到的broker地址
configs.put("bootstrap.servers", "192.168.1.111:9092");
// 指定key的序列化类
configs.put("key.serializer", IntegerSerializer.class);
// 指定value的序列化类
configs.put("value.serializer", StringSerializer.class);
// configs.put("acks", "all");
// configs.put("reties", "3");
KafkaProducer<Integer, String> producer = new KafkaProducer<Integer, String>(configs);
// 用于设置用户自定义的消息头字段
List<Header> headers = new ArrayList<>();
headers.add(new RecordHeader("biz.name", "producer.demo".getBytes()));
for (int i = 0; i < 100; i++) {
ProducerRecord<Integer, String> record = new ProducerRecord<Integer, String>(
"topic_1",
0,
i,
"hello yanqi " + i,
headers
);
// 消息的同步确认
// final Future<RecordMetadata> future = producer.send(record);
// final RecordMetadata metadata = future.get();
// System.out.println("消息的主题：" + metadata.topic());
// System.out.println("消息的分区号：" + metadata.partition());
// System.out.println("消息的偏移量：" + metadata.offset());
// 消息的异步确认
producer.send(record, new Callback() {
@Override
public void onCompletion(RecordMetadata metadata, Exception exception) {
if (exception == null) {
System.out.println("消息的主题：" + metadata.topic());
System.out.println("消息的分区号：" + metadata.partition());
System.out.println("消息的偏移量：" + metadata.offset());
} else {
System.out.println("异常消息：" + exception.getMessage());
}
}
});
}
// 关闭生产者
producer.close();
}
}二、生成者实验代码
### --- 生成者：MyConsumer2
package com.yanqi.kafka.demo.consumer;
import org.apache.kafka.clients.consumer.ConsumerConfig;
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.IntegerDeserializer;
import org.apache.kafka.common.serialization.StringDeserializer;
import java.util.Arrays;
import java.util.HashMap;
import java.util.Map;
import java.util.function.Consumer;
public class MyConsumer2 {
public static void main(String[] args) {
Map<String, Object> configs = new HashMap<>();
// node1对应于192.168.1.111，windows的hosts文件中手动配置域名解析
configs.put(ConsumerConfig.BOOTSTRAP_SERVERS_CONFIG, "node1:9092");
// 使用常量代替手写的字符串，配置key的反序列化器
configs.put(ConsumerConfig.KEY_DESERIALIZER_CLASS_CONFIG, IntegerDeserializer.class);
// 配置value的反序列化器
configs.put(ConsumerConfig.VALUE_DESERIALIZER_CLASS_CONFIG, StringDeserializer.class);
// 配置消费组ID
configs.put(ConsumerConfig.GROUP_ID_CONFIG, "consumer_demo2");
// 如果找不到当前消费者的有效偏移量，则自动重置到最开始
// latest表示直接重置到消息偏移量的最后一个
configs.put(ConsumerConfig.AUTO_OFFSET_RESET_CONFIG, "earliest");
KafkaConsumer<Integer, String> consumer = new KafkaConsumer<Integer, String>(configs);
// 先订阅，再消费
consumer.subscribe(Arrays.asList("topic_1"));
while (true) {
// 如果主题中没有可以消费的消息，则该方法可以放到while循环中，每过3秒重新拉取一次
// 如果还没有拉取到，过3秒再次拉取，防止while循环太密集的poll调用。
// 批量从主题的分区拉取消息
final ConsumerRecords<Integer, String> consumerRecords = consumer.poll(3_000);
// 遍历本次从主题的分区拉取的批量消息
consumerRecords.forEach(new Consumer<ConsumerRecord<Integer, String>>() {
@Override
public void accept(ConsumerRecord<Integer, String> record) {
System.out.println(record.topic() + "\t"
+ record.partition() + "\t"
+ record.offset() + "\t"
+ record.key() + "\t"
+ record.value());
}
});
}
// consumer.close();
}
}三、实验流程
### --- 运行MyConsumer2
D:\JAVA\jdk1.8.0_231\bin\java.exe "-javaagent:D:\IntelliJIDEA\IntelliJ IDEA 2019.3.3\lib\idea_rt.jar=63222:D:\IntelliJIDEA\IntelliJ IDEA 2019.3.3\bin" -Dfile.encoding=UTF-8 -classpath D:\JAVA\jdk1.8.0_231\jre\lib\charsets.jar;D:\JAVA\jdk1.8.0_231\jre\lib\deploy.jar;D:\JAVA\jdk1.8.0_231\jre\lib\ext\access-bridge-64.jar;D:\JAVA\jdk1.8.0_231\jre\lib\ext\cldrdata.jar;D:\JAVA\jdk1.8.0_231\jre\lib\ext\dnsns.jar;D:\JAVA\jdk1.8.0_231\jre\lib\ext\jaccess.jar;D:\JAVA\jdk1.8.0_231\jre\lib\ext\jfxrt.jar;D:\JAVA\jdk1.8.0_231\jre\lib\ext\localedata.jar;D:\JAVA\jdk1.8.0_231\jre\lib\ext\nashorn.jar;D:\JAVA\jdk1.8.0_231\jre\lib\ext\sunec.jar;D:\JAVA\jdk1.8.0_231\jre\lib\ext\sunjce_provider.jar;D:\JAVA\jdk1.8.0_231\jre\lib\ext\sunmscapi.jar;D:\JAVA\jdk1.8.0_231\jre\lib\ext\sunpkcs11.jar;D:\JAVA\jdk1.8.0_231\jre\lib\ext\zipfs.jar;D:\JAVA\jdk1.8.0_231\jre\lib\javaws.jar;D:\JAVA\jdk1.8.0_231\jre\lib\jce.jar;D:\JAVA\jdk1.8.0_231\jre\lib\jfr.jar;D:\JAVA\jdk1.8.0_231\jre\lib\jfxswt.jar;D:\JAVA\jdk1.8.0_231\jre\lib\jsse.jar;D:\JAVA\jdk1.8.0_231\jre\lib\management-agent.jar;D:\JAVA\jdk1.8.0_231\jre\lib\plugin.jar;D:\JAVA\jdk1.8.0_231\jre\lib\resources.jar;D:\JAVA\jdk1.8.0_231\jre\lib\rt.jar;E:\NO.Z.10000——javaproject\NO.Z.00002.Hadoop\kafka_demo\demo-01-producer-consumer\target\classes;C:\Users\Administrator\.m2\repository\org\apache\kafka\kafka-clients\1.0.2\kafka-clients-1.0.2.jar;C:\Users\Administrator\.m2\repository\org\lz4\lz4-java\1.4\lz4-java-1.4.jar;C:\Users\Administrator\.m2\repository\org\xerial\snappy\snappy-java\1.1.4\snappy-java-1.1.4.jar;C:\Users\Administrator\.m2\repository\org\slf4j\slf4j-api\1.7.25\slf4j-api-1.7.25.jar com.yanqi.kafka.demo.consumer.MyConsumer2
topic_1 0 0 0 hello yanqi 0
~~等待消费消息
topic_1 0 2 1 hello yanqi 1
topic_1 0 3 2 hello yanqi 2
#~~~省略部分输出
topic_1 0 99 98 hello yanqi 98
topic_1 0 100 99 hello yanqi 99
### --- 运行MyProducer2
D:\JAVA\jdk1.8.0_231\bin\java.exe "-javaagent:D:\IntelliJIDEA\IntelliJ IDEA 2019.3.3\lib\idea_rt.jar=63245:D:\IntelliJIDEA\IntelliJ IDEA 2019.3.3\bin" -Dfile.encoding=UTF-8 -classpath D:\JAVA\jdk1.8.0_231\jre\lib\charsets.jar;D:\JAVA\jdk1.8.0_231\jre\lib\deploy.jar;D:\JAVA\jdk1.8.0_231\jre\lib\ext\access-bridge-64.jar;D:\JAVA\jdk1.8.0_231\jre\lib\ext\cldrdata.jar;D:\JAVA\jdk1.8.0_231\jre\lib\ext\dnsns.jar;D:\JAVA\jdk1.8.0_231\jre\lib\ext\jaccess.jar;D:\JAVA\jdk1.8.0_231\jre\lib\ext\jfxrt.jar;D:\JAVA\jdk1.8.0_231\jre\lib\ext\localedata.jar;D:\JAVA\jdk1.8.0_231\jre\lib\ext\nashorn.jar;D:\JAVA\jdk1.8.0_231\jre\lib\ext\sunec.jar;D:\JAVA\jdk1.8.0_231\jre\lib\ext\sunjce_provider.jar;D:\JAVA\jdk1.8.0_231\jre\lib\ext\sunmscapi.jar;D:\JAVA\jdk1.8.0_231\jre\lib\ext\sunpkcs11.jar;D:\JAVA\jdk1.8.0_231\jre\lib\ext\zipfs.jar;D:\JAVA\jdk1.8.0_231\jre\lib\javaws.jar;D:\JAVA\jdk1.8.0_231\jre\lib\jce.jar;D:\JAVA\jdk1.8.0_231\jre\lib\jfr.jar;D:\JAVA\jdk1.8.0_231\jre\lib\jfxswt.jar;D:\JAVA\jdk1.8.0_231\jre\lib\jsse.jar;D:\JAVA\jdk1.8.0_231\jre\lib\management-agent.jar;D:\JAVA\jdk1.8.0_231\jre\lib\plugin.jar;D:\JAVA\jdk1.8.0_231\jre\lib\resources.jar;D:\JAVA\jdk1.8.0_231\jre\lib\rt.jar;E:\NO.Z.10000——javaproject\NO.Z.00002.Hadoop\kafka_demo\demo-01-producer-consumer\target\classes;C:\Users\Administrator\.m2\repository\org\apache\kafka\kafka-clients\1.0.2\kafka-clients-1.0.2.jar;C:\Users\Administrator\.m2\repository\org\lz4\lz4-java\1.4\lz4-java-1.4.jar;C:\Users\Administrator\.m2\repository\org\xerial\snappy\snappy-java\1.1.4\snappy-java-1.1.4.jar;C:\Users\Administrator\.m2\repository\org\slf4j\slf4j-api\1.7.25\slf4j-api-1.7.25.jar com.yanqi.kafka.demo.producer.MyProducer2
SLF4J: Failed to load class "org.slf4j.impl.StaticLoggerBinder".
SLF4J: Defaulting to no-operation (NOP) logger implementation
SLF4J: See http://www.slf4j.org/codes.html#StaticLoggerBinder for further details.
消息的主题：topic_1
消息的分区号：0
消息的偏移量：1
消息的主题：topic_1
消息的分区号：0
消息的偏移量：2
#~~~省略部分输出
消息的主题：topic_1
消息的分区号：0
消息的偏移量：98
消息的主题：topic_1
消息的分区号：0
消息的偏移量：99
消息的主题：topic_1
消息的分区号：0
消息的偏移量：100### --- 查看消费的消息
[root@hadoop ~]# kafka-console-consumer.sh --bootstrap-server localhost:9092 --topic topic_1 --from-beginning
hello yanqi 1
hello yanqi 2
#~~~省略部分输出
hello yanqi 98
hello yanqi 99Walter Savage Landor:strove with none,for none was worth my strife.Nature I loved and, next to Nature, Art:I warm'd both hands before the fire of life.It sinks, and I am ready to depart
——W.S.Landor
