Java serialization

serialization.java

package consulting.crafters.serialization;

import com.esotericsoftware.kryo.Kryo;
import com.esotericsoftware.kryo.io.Input;
import com.esotericsoftware.kryo.io.Output;
import com.fasterxml.jackson.core.JsonProcessingException;
import com.fasterxml.jackson.databind.ObjectMapper;
import com.fasterxml.jackson.databind.SerializationFeature;
import com.fasterxml.jackson.datatype.jsr310.JavaTimeModule;
import com.github.javafaker.Faker;
import lombok.AllArgsConstructor;
import lombok.Data;
import lombok.NoArgsConstructor;
import lombok.val;

import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.time.LocalDate;
import java.util.List;
import java.util.stream.IntStream;

import static java.time.ZoneId.systemDefault;
import static java.util.stream.Collectors.toList;
import static org.apache.commons.io.FileUtils.byteCountToDisplaySize;
import static org.assertj.core.api.Assertions.assertThat;

public class Main {
    private final static ObjectMapper objectMapper;
    private final static Kryo kryo;

    static {
        objectMapper = new ObjectMapper()
                .registerModule(new JavaTimeModule())
                .disable(SerializationFeature.WRITE_DATES_AS_TIMESTAMPS);

        kryo = new Kryo();
        kryo.register(Person.class);
    }

    public static void main(String[] args) throws Exception {
        val faker = new Faker();
        val people = new People(IntStream.range(1, 50000)
                .mapToObj(it -> new Person(
                        faker.name().firstName(),
                        faker.name().lastName(),
                        faker.date().birthday(20, 60).toInstant().atZone(systemDefault()).toLocalDate(),
                        new Address(
                                faker.address().streetAddress(),
                                faker.address().zipCode(),
                                faker.address().city()
                        )
                ))
                .collect(toList()));

        val jsonBytes = serializeUsingJackson(people);
        val kryoOut = serializeUsingKryo(people);

        System.out.println("Size of jackson serialized = " + byteCountToDisplaySize(jsonBytes.length)); // = 7 MB
        System.out.println("Size of kyro serialized    = " + byteCountToDisplaySize(kryoOut.length));   // = 2 MB

        val jsonPeople = deserializeUsingJackson(jsonBytes);
        val kryoPeople = deserializeUsingKryo(kryoOut);

        assertThat(jsonPeople).isEqualTo(people);
        assertThat(kryoPeople).isEqualTo(people);
    }

    private static byte[] serializeUsingJackson(People people) throws JsonProcessingException {
        return objectMapper
                .writeValueAsString(people)
                .getBytes();
    }

    private static People deserializeUsingJackson(byte[] bytes) throws Exception {
        return objectMapper.readValue(bytes, People.class);
    }

    private static byte[] serializeUsingKryo(People people) {
        val out = new ByteArrayOutputStream();
        val kryoOutput = new Output(out);
        kryo.writeObject(kryoOutput, people);
        kryoOutput.flush();
        kryoOutput.close();

        return out.toByteArray();
    }

    private static People deserializeUsingKryo(byte[] bytes) {
        val input = new Input(new ByteArrayInputStream(bytes));
        val result = kryo.readObject(input, People.class);
        input.close();
        return result;
    }
}

@Data
@NoArgsConstructor
@AllArgsConstructor
class People {
    private List<Person> people;
}

@Data
@NoArgsConstructor
@AllArgsConstructor
class Person {
    private String firstName;
    private String lastName;
    private LocalDate birthday;
    private Address address;
}

@Data
@NoArgsConstructor
@AllArgsConstructor
class Address {
    private String street;
    private String zipCode;
    private String city;
}

// compile group: 'org.projectlombok', name: 'lombok', version:'1.16.20'
// compile group: 'com.esotericsoftware', name: 'kryo', version:'4.0.2'
// compile group: 'com.fasterxml.jackson.core', name: 'jackson-databind', version:'2.9.4'
// compile group: 'com.fasterxml.jackson.datatype', name: 'jackson-datatype-jsr310', version:'2.9.4'
// compile group: 'commons-io', name: 'commons-io', version:'2.3'
// compile group: 'com.github.javafaker', name: 'javafaker', version:'0.16'
// compile group: 'org.assertj', name: 'assertj-core', version:'3.11.1'