domain-id

An implementation for Domain IDs, as suggested by Implementing Domain Driven Design.

This library includes:

• a DomainId base class;
• a hibernate UserType, which allows you to map the IDs directly into entities;
• a Jackson serializer and deserializer.

Importing:

dependencies {
    implementation('io.github.acdcjunior:domain-id-all:0.2.0')

<dependencies>
	<dependency>
		<groupId>io.github.acdcjunior</groupId>
		<artifactId>domain-id-all</artifactId>
		<version>0.2.0</version>
	</dependency>

NOTE: Although domain-id-hibernate-usertype's code depends on hibernate and JPA, its .jar does not bring any dependencies. That is intentional. Our purpose is not to force any specific Hibernate or Jackson (in the case of domain-id-serializer-converter) minor versions. You should, therefore, declare the dependencies as usual (in your build.gradle or pom.xml) and guarantee everything works via at least one runtime test.

Declaring

In order to use an ID, you must declare some classes first. Basically, you'll declare the ID and that's all.

The hibernate UserType is automatically registered. The Jackson serializer/deserializer may be registered, if you'll need it.

The ID class:

// src/main/java/com/myservice/domain/myentity/MyEntityId.java
package com.myservice.domain.myentity;

import io.github.acdcjunior.domainid.DomainId;

public class MyEntityId extends DomainId {
    public MyEntityId(long id) {
        super(id);
    }
}

An hibernate UserType will be automatically registered for that ID class.

Add, if desired, the Jackson serializer/deserializer

// src/main/java/com/myservice/MyServiceApplication.java
package com.myservice;

// ...   
import io.github.acdcjunior.domainid.DomainIdSerializer;

@SpringBootApplication(scanBasePackages = "com.myservice", scanBasePackageClasses = DomainIdSerializer.class)
public class MyServiceApplication {

Usage

After the declarations above, use as follows:

Non-ID field:

@Entity
@Table(name = "MY_ENTITY", schema = "MYSERVICE")
public class MyEntity {

    // ...

    @Column
    private OtherEntityId otherEntity;

Using as @Id and auto-generated using a Sequence:

import io.github.acdcjunior.domainid.hibernate.sequence.DomainIdSequenceStyleGenerator;
import org.hibernate.annotations.GenericGenerator;

import javax.persistence.*;

@Entity
@Table(name = "MY_ENTITY", schema = "MYSERVICE")
public class MyEntity {

    @Id
    @GenericGenerator(
            name = "SEQ_MY_ENTITY",
            strategy = DomainIdSequenceStyleGenerator.SEQUENCE,
            parameters = @org.hibernate.annotations.Parameter(name = "sequence_name", value = "MYSERVICE.SEQ_MY_ENTITY")
    )
    @GeneratedValue(generator = "SEQ_MY_ENTITY", strategy = GenerationType.SEQUENCE)
    @Column
    private MyEntityId id;

Details

@GenericGenerator - Parameters:

• sequence_name: Sequence's full name, including the schema/owner name. Example: MY_SCHEMA.MY_ENTITY_SEQ.