Kafka the producer sequence into binary objects pushed Broker, the following is an example of custom serialization, the sequence of a User object;
First, the introduction of jackson-mapper-asl
<dependency> <groupId>org.codehaus.jackson</groupId> <artifactId>jackson-mapper-asl</artifactId> <version>1.9.12</version> </dependency>
It is then defined to be the sequence of the entity classes:
package cn.org.fubin; public class User { private String firstName; private String lastName; private int age; private String address; public User() { } public User(String firstName, String lastName, int age, String address) { this.firstName = firstName; this.lastName = lastName; this.age = age; this.address = address; } public String getFirstName() { return firstName; } public void setFirstName(String firstName) { this.firstName = firstName; } public String getLastName() { return lastName; } public void setLastName(String lastName) { this.lastName = lastName; } public int getAge() { return age; } public void setAge(int age) { this.age = age; } public String getAddress() { return address; } public void setAddress(String address) { this.address = address; } @Override public String toString() { return "User{" + "firstName='" + firstName + '\'' + ", lastName='" + lastName + '\'' + ", age=" + age + ", address='" + address + '\'' + '}'; } }
Next, create a sequence of classes that implement the interface Kafka Serializer provided by the client:
import org.apache.kafka.common.serialization.Serializer; import org.codehaus.jackson.map.ObjectMapper; import java.io.IOException; import java.util.Map; public class UserSerializer implements Serializer { private ObjectMapper objectMapper; public void configure(Map configs, boolean isKey) { objectMapper = new ObjectMapper(); } public byte[] serialize(String topic, Object data) { byte[] ret = null; try { ret = objectMapper.writeValueAsString(data).getBytes("utf-8"); } catch (IOException e) { System.out.println ( "failed serialization" ); e.printStackTrace (); } Return the right; } public void close() { } }
Kafka realized default provides the following:
import org.apache.kafka.clients.producer.*; import org.apache.kafka.common.errors.RetriableException; import java.util.Properties; import java.util.concurrent.ExecutionException; /** * * Retry abnormal * 1. Partition copy is not available * 2. Controller is currently unavailable * 3. Network transient faults * * Self-healing, than the number of retries required discretion * * * Do not retry abnormal * 1. Send message oversized * 2. The sequence of abnormal failure * 3. Other types of abnormal * * */ public class KafkaProducerDemo { public static void main(String[] args) throws ExecutionException, InterruptedException { Properties properties = new Properties(); properties.put("bootstrap.servers", "localhost:9092,localhost:9093,localhost:9094"); properties.put("key.serializer", "org.apache.kafka.common.serialization.StringSerializer"); properties.put("value.serializer", "cn.org.fubin.UserSerializer"); properties.put("acks", "-1"); System.out.println(ProducerConfig.ACKS_CONFIG); properties.put("retries", "3"); properties.put("batch.size", 1048576); properties.put("linger.ms", 10); properties.put("buffer.memory", "33554432"); System.out.println(ProducerConfig.BUFFER_MEMORY_CONFIG); properties.put(ProducerConfig.COMPRESSION_TYPE_CONFIG,"lz4"); properties.put("max.block.ms", "3000"); String topic = "test-topic"; Producer<String,User> producer = new KafkaProducer<String, User>(properties); User user = new User("a","b",23,"china"); ProducerRecord<String ,User> record = new ProducerRecord<String, User>(topic,user); producer.send(record).get(); producer.close(); } }
Then, in the main class declared good sequence specified class, and transmits a User entity: