In this blog post, we will explore how to use the Hazelcast IMDG (In-Memory Data Grid) storage format in Java applications. Hazelcast is an open-source, distributed, in-memory caching solution that provides clustering and partitioning capabilities, allowing you to store large amounts of data in a distributed and highly available manner.

Hazelcast IMDG provides a variety of storage formats to store your data. One of the most commonly used formats is the binary storage format. The binary format provides efficient storage and serialization of your objects, enabling faster read and write operations.

Setting up Hazelcast IMDG

First, you need to include the Hazelcast IMDG dependency in your Java project. You can either download the Hazelcast IMDG JAR file manually or include it as a Maven dependency in your pom.xml file.

<dependency>
    <groupId>com.hazelcast</groupId>
    <artifactId>hazelcast</artifactId>
    <version>{hazelcast-version}</version>
</dependency>

Once you have added the Hazelcast IMDG dependency, you need to initialize an instance of HazelcastInstance. This can be done by creating a Config object and configuring it according to your requirements.

Config config = new Config();
HazelcastInstance hazelcastInstance = Hazelcast.newHazelcastInstance(config);

Using the Binary Storage Format

To use the binary storage format in Hazelcast IMDG, you need to define your data classes using Portable serialization. The Portable interface allows you to serialize your objects in a compact binary format, optimizing the storage size and enabling efficient access to the data.

Here’s an example of a Person class implemented using Portable serialization:

public class Person implements Portable {
    private String name;
    private int age;

    // Constructors, getters, and setters

    @Override
    public int getFactoryId() {
        return PersonFactory.FACTORY_ID;
    }

    @Override
    public int getClassId() {
        return PersonFactory.PERSON_CLASS_ID;
    }

    @Override
    public void writePortable(PortableWriter writer) throws IOException {
        writer.writeUTF("name", name);
        writer.writeInt("age", age);
    }

    @Override
    public void readPortable(PortableReader reader) throws IOException {
        name = reader.readUTF("name");
        age = reader.readInt("age");
    }
}

In the above example, the Person class implements the Portable interface, providing the necessary methods to write and read data in the binary format.

To store your Person objects in Hazelcast IMDG, you can use the distributed IMap interface. Here’s an example of storing and retrieving Person objects:

IMap<Long, Person> personMap = hazelcastInstance.getMap("personMap");
personMap.put(1L, new Person("John", 30));

Person john = personMap.get(1L);
System.out.println(john.getName() + " is " + john.getAge() + " years old.");

In the above example, we store a Person object with ID 1 in the personMap. Then, we retrieve the Person object and print its name and age.

Conclusion

In this blog post, we have explored how to use the Hazelcast IMDG storage format in Java applications. By using the binary storage format and leveraging the Portable serialization, you can optimize the storage and retrieval of your data in Hazelcast IMDG. This can lead to improved read and write performance in distributed and highly available applications.

#tech #Hazelcast #storage #Java