• What is DTO_Annotation?
• Examples
  • Generate DTOs
  • Generate DTOs & Entity
• Using DTO_Annotation
  • Maven
  • Gradle
  • No Dependency Management Tool
  • IntelliJ
• Licensing

What is DTO_Annotation?

DTO_Annotation is a Java annotation processor designed to generate DTOs classes at compile time from entity classes to avoid manually creating them.

Examples

Generate DTOs

We have the following EntityTest class :

package rabah.usthb;

import jakarta.persistence.*;
import org.springframework.data.annotation.Id;
import io.github.rabah.usthb.DTO;
import io.github.rabah.usthb.DTOField;
import java.util.HashMap;
import java.util.Map;
import lombok.Data;
import lombok.Value;

@Entity
@Inheritance(strategy = InheritanceType.JOINED)
@DTO(name = {"get", "post"}, packageName="io.rabah")
@Data
@Value
public class EntityTest {

    @Id
    @GeneratedValue(strategy= GenerationType.AUTO)
    private long id;

    @Column(nullable = true)
    @DTOField
    private String name;

    @DTOField
    private Map<String, Integer> tags = new HashMap<>();

   
    @DTOField(excludedDTO = {"get"})
    private String password;

}

DTO_Annotation will generate two DTOs (get, post) from EntityTest , fields that are annotated with @DTOField are included in the DTOs unless they are excluded with excludedDTO array, and all annotation present below @DTO will be included in the DTOs in this case they are @Data and @Value, all generated DTOs will go the package "io.rabah.dto" :

package io.rabah.dto;

import java.util.HashMap;
import java.util.Map;
import lombok.Data;
import lombok.Value;

@Data
@Value
public class getEntityTestDTO {

    private String name;
    private Map<String, Integer> tags = new HashMap<>();

}

package io.rabah.dto;

import java.util.HashMap;
import java.util.Map;
import lombok.Data;
import lombok.Value;

@Data
@Value
public class postEntityTestDTO {

    private String name;
    private Map<String, Integer> tags = new HashMap<>();
    private String password;
}

Generate DTOs & Entity

DTO_Annotation also allows us to add extra field that only figures in DTOs but to do so it also needs to generate the Entity class , so whenever a class has a field with @DTOExtraField it has to also generate the entity example following the EntityTest :

package rabah.usthb;

import jakarta.persistence.*;
import org.springframework.data.annotation.Id;
import io.github.rabah.usthb.DTO;
import io.github.rabah.usthb.DTOField;
import io.github.rabah.usthb.DTOExtraField;
import java.util.HashMap;
import java.util.Map;


@Entity
@Inheritance(strategy = InheritanceType.JOINED)
@DTO
public class EntityTest {

    @Id
    @GeneratedValue(strategy= GenerationType.AUTO)
    private long id;

    @Column(nullable = true)
    private String firstName;

    @Column(nullable = true)
    private String lastName;

    @DTOExtraField
    private String fullName;
    
    @DTOField
    private Map<String, Integer> tags = new HashMap<>();

   
    private String password;

}

DTO_Annotation will generate one DTO that has full name as its extra field, and an entity that doesn't have full name :

package rabah.usthb.entity;

import jakarta.persistence.*;
import org.springframework.data.annotation.Id;
import java.util.HashMap;
import java.util.Map;


@Entity
@Inheritance(strategy = InheritanceType.JOINED)
@DTO
public class EntityTest {

    @Id
    @GeneratedValue(strategy= GenerationType.AUTO)
    private long id;

    @Column(nullable = true)
    private String firstName;

    @Column(nullable = true)
    private String lastName;
    
    
    private Map<String, Integer> tags = new HashMap<>();

    private String password;

}

package rabah.usthb.dto;

import java.util.HashMap;
import java.util.Map;


public class EntityTestDTO {

    private String fullName;
    private Map<String, Integer> tags = new HashMap<>(); 

}

Using DTO_Annotation

Maven

For Maven-based projects, add the following to your POM file in order to use DTO_Annotation (the dependencies are available at Maven Central):

    <dependencies>
        <dependency>
            <groupId>io.github.rabah-usthb</groupId>
            <artifactId>DTO_Annotation</artifactId>
            <version>1.1.0</version>
        </dependency>
    </dependencies>

Gradle

For Gradle, you need something along the following lines:

dependencies {
    implementation 'io.github.rabah-usthb:DTO_Annotation:1.1.0'
}

No Dependency Management Tool

If you don't work with a dependency management tool, you can obtain a distribution bundle from Releases page.

IntelliJ

Make sure that you have at least IntelliJ 2018.2.x (needed since support for annotationProcessors from the maven-compiler-plugin is from that version). Enable annotation processing in IntelliJ (Build, Execution, Deployment -> Compiler -> Annotation Processors)

Licensing

DTO_Annotation is licensed under the Apache License, Version 2.0 (the "License"); you may not use this project except in compliance with the License. You may obtain a copy of the License at https://www.apache.org/licenses/LICENSE-2.0.