这是indexloc提供的服务，不要输入任何密码
Skip to content

BAEL-9152: Set the Null Value for a Target Property in Mapstruct #18869

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
merged 2 commits into from
Oct 24, 2025
Merged

BAEL-9152: Set the Null Value for a Target Property in Mapstruct #18869

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
2 commits
Select commit Hold shift + click to select a range
52832db
wraps up mapping using expression
pedrolopes9-7 Oct 8, 2025
a258e87
final version
pedrolopes9-7 Oct 16, 2025
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
37 changes: 37 additions & 0 deletions mapstruct-3/src/main/java/com/baeldung/setnullproperty/dto/ArticleDTO.java
View file
Open in desktop
Original file line number Diff line number Diff line change
@@ -0,0 +1,37 @@
package com.baeldung.setnullproperty.dto;

import java.util.Objects;

public class ArticleDTO extends ReviewableDTO {

private String title;

public ArticleDTO(String title) {
this.title = title;
}

public ArticleDTO() {
}

public String getTitle() {
return title;
}

public void setTitle(String title) {
this.title = title;
}

@Override
public boolean equals(Object o) {
if (o == null || getClass() != o.getClass()) {
return false;
}
ArticleDTO that = (ArticleDTO) o;
return Objects.equals(title, that.title);
}

@Override
public int hashCode() {
return Objects.hashCode(title);
}
}
37 changes: 37 additions & 0 deletions mapstruct-3/src/main/java/com/baeldung/setnullproperty/dto/ReviewableDTO.java
View file
Open in desktop
Original file line number Diff line number Diff line change
@@ -0,0 +1,37 @@
package com.baeldung.setnullproperty.dto;

import java.util.Objects;

public class ReviewableDTO {

private String title;

public ReviewableDTO() {
}

public ReviewableDTO(String title) {
this.title = title;
}

public String getTitle() {
return title;
}

public void setTitle(String title) {
this.title = title;
}

@Override
public boolean equals(Object o) {
if (o == null || getClass() != o.getClass()) {
return false;
}
ReviewableDTO that = (ReviewableDTO) o;
return Objects.equals(title, that.title);
}

@Override
public int hashCode() {
return Objects.hashCode(title);
}
}
42 changes: 42 additions & 0 deletions mapstruct-3/src/main/java/com/baeldung/setnullproperty/dto/WeeklyNewsDTO.java
View file
Open in desktop
Original file line number Diff line number Diff line change
@@ -0,0 +1,42 @@
package com.baeldung.setnullproperty.dto;

import java.util.Objects;

public class WeeklyNewsDTO extends ReviewableDTO {

private String title;

public WeeklyNewsDTO() {
}

public WeeklyNewsDTO(String title1) {
this.title = title1;
}

@Override
public String getTitle() {
return title;
}

@Override
public void setTitle(String title) {
this.title = title;
}

@Override
public boolean equals(Object o) {
if (o == null || getClass() != o.getClass()) {
return false;
}
if (!super.equals(o)) {
return false;
}
WeeklyNewsDTO that = (WeeklyNewsDTO) o;
return Objects.equals(title, that.title);
}

@Override
public int hashCode() {
return Objects.hash(super.hashCode(), title);
}
}
38 changes: 38 additions & 0 deletions mapstruct-3/src/main/java/com/baeldung/setnullproperty/entity/Article.java
View file
Open in desktop
Original file line number Diff line number Diff line change
@@ -0,0 +1,38 @@
package com.baeldung.setnullproperty.entity;

import java.util.Objects;

public class Article extends Reviewable {

private String title;

public Article(String id, String reviewedBy) {
this.id = id;
this.reviewedBy = reviewedBy;
}

public Article() {
}

@Override
public boolean equals(Object o) {
if (o == null || getClass() != o.getClass()) {
return false;
}
Article article = (Article) o;
return Objects.equals(id, article.id) && Objects.equals(reviewedBy, article.reviewedBy);
}

@Override
public int hashCode() {
return Objects.hash(id, reviewedBy);
}

public String getTitle() {
return title;
}

public void setTitle(String title) {
this.title = title;
}
}
54 changes: 54 additions & 0 deletions mapstruct-3/src/main/java/com/baeldung/setnullproperty/entity/Reviewable.java
View file
Open in desktop
Original file line number Diff line number Diff line change
@@ -0,0 +1,54 @@
package com.baeldung.setnullproperty.entity;

import java.util.Objects;

public class Reviewable {
protected String id;
protected String reviewedBy;
protected String title;

public Reviewable(String reviewedBy) {
this.reviewedBy = reviewedBy;
}

public Reviewable() {
}

public String getReviewedBy() {
return reviewedBy;
}

public void setReviewedBy(String reviewedBy) {
this.reviewedBy = reviewedBy;
}

public String getId() {
return id;
}

public void setId(String id) {
this.id = id;
}

public String getTitle() {
return title;
}

public void setTitle(String title) {
this.title = title;
}

@Override
public boolean equals(Object o) {
if (o == null || getClass() != o.getClass()) {
return false;
}
Reviewable that = (Reviewable) o;
return Objects.equals(reviewedBy, that.reviewedBy);
}

@Override
public int hashCode() {
return Objects.hashCode(reviewedBy);
}
}
27 changes: 27 additions & 0 deletions mapstruct-3/src/main/java/com/baeldung/setnullproperty/entity/WeeklyNews.java
View file
Open in desktop
Original file line number Diff line number Diff line change
@@ -0,0 +1,27 @@
package com.baeldung.setnullproperty.entity;

import java.util.Objects;

public class WeeklyNews extends Reviewable {

public WeeklyNews() {
}

public WeeklyNews(String reviewedBy) {
this.reviewedBy = reviewedBy;
}

@Override
public boolean equals(Object o) {
if (o == null || getClass() != o.getClass()) {
return false;
}
WeeklyNews that = (WeeklyNews) o;
return Objects.equals(reviewedBy, that.reviewedBy);
}

@Override
public int hashCode() {
return Objects.hashCode(reviewedBy);
}
}
52 changes: 52 additions & 0 deletions mapstruct-3/src/main/java/com/baeldung/setnullproperty/mapper/ArticleMapper.java
View file
Open in desktop
Original file line number Diff line number Diff line change
@@ -0,0 +1,52 @@
package com.baeldung.setnullproperty.mapper;

import org.mapstruct.AfterMapping;
import org.mapstruct.Mapper;
import org.mapstruct.Mapping;
import org.mapstruct.MappingTarget;
import org.mapstruct.Named;

import com.baeldung.setnullproperty.dto.ArticleDTO;
import com.baeldung.setnullproperty.entity.Article;

@Mapper(uses = ReviewableMapper.class)
public interface ArticleMapper {

@Mapping(target = "title", source = "dto.title")
@Mapping(target = "id", source = "persisted.id")
@Mapping(target = "reviewedBy", expression = "java(null)")
Article toArticleUsingExpression(ArticleDTO dto, Article persisted);

@Mapping(target = "title", source = "dto.title")
@Mapping(target = "id", source = "persisted.id")
@Mapping(target = "reviewedBy", expression = "java(getDefaultReviewStatus())")
Article toArticleUsingExpressionMethod(ArticleDTO dto, Article persisted);

default String getDefaultReviewStatus() {
return null;
}

@Mapping(target = "title", source = "dto.title")
@Mapping(target = "id", source = "persisted.id")
@Mapping(target = "reviewedBy", ignore = true)
Article toArticleUsingIgnore(ArticleDTO dto, Article persisted);

@AfterMapping
default void setNullReviewedBy(@MappingTarget Article article) {
article.setReviewedBy(null);
}

@Mapping(target = "title", source = "dto.title")
@Mapping(target = "id", source = "persisted.id")
Article toArticleUsingAfterMapping(ArticleDTO dto, Article persisted);

@Mapping(target = "title", source = "dto.title")
@Mapping(target = "id", source = "persisted.id")
@Mapping(target = "reviewedBy", qualifiedByName = "toNull")
Article toArticleUsingQualifiedBy(ArticleDTO dto, Article persisted);

@Named("toNull")
default String mapToNull(String property) {
return null;
}
}
22 changes: 22 additions & 0 deletions mapstruct-3/src/main/java/com/baeldung/setnullproperty/mapper/ReviewableMapper.java
View file
Open in desktop
Original file line number Diff line number Diff line change
@@ -0,0 +1,22 @@
package com.baeldung.setnullproperty.mapper;

import org.mapstruct.Mapper;
import org.mapstruct.Mapping;
import org.mapstruct.SubclassMapping;

import com.baeldung.setnullproperty.dto.ArticleDTO;
import com.baeldung.setnullproperty.dto.ReviewableDTO;
import com.baeldung.setnullproperty.dto.WeeklyNewsDTO;
import com.baeldung.setnullproperty.entity.Article;
import com.baeldung.setnullproperty.entity.Reviewable;
import com.baeldung.setnullproperty.entity.WeeklyNews;

@Mapper
public interface ReviewableMapper {

@SubclassMapping(source = ArticleDTO.class, target = Article.class)
@SubclassMapping(source = WeeklyNewsDTO.class, target = WeeklyNews.class)
@Mapping(target = "reviewedBy", expression = "java(null)")
Reviewable toReviewable(ReviewableDTO dto);

}
78 changes: 78 additions & 0 deletions mapstruct-3/src/test/java/com/baeldung/setnullproperty/mapper/ArticleMapperUnitTest.java
View file
Open in desktop
Original file line number Diff line number Diff line change
@@ -0,0 +1,78 @@
package com.baeldung.setnullproperty.mapper;

import static org.assertj.core.api.AssertionsForClassTypes.assertThat;

import org.junit.jupiter.api.BeforeEach;
import org.junit.jupiter.api.Test;
import org.mapstruct.factory.Mappers;

import com.baeldung.setnullproperty.dto.ArticleDTO;
import com.baeldung.setnullproperty.dto.WeeklyNewsDTO;
import com.baeldung.setnullproperty.entity.Article;
import com.baeldung.setnullproperty.entity.Reviewable;
import com.baeldung.setnullproperty.entity.WeeklyNews;

class ArticleMapperUnitTest {

private ArticleMapper articleMapper;
private ReviewableMapper reviewableMapper;

@BeforeEach
void setUp() {
articleMapper = Mappers.getMapper(ArticleMapper.class);
reviewableMapper = Mappers.getMapper(ReviewableMapper.class);
}

@Test
void givenArticleDTO_whenToArticleUsingExpression_thenReturnsArticleWithNullStatus() {
Article oldArticle1 = new Article("ID-1", "John Doe");
Article oldArticle2 = new Article("ID-2", "John Doe");

Article result1 = articleMapper.toArticleUsingExpression(new ArticleDTO("Updated article 1 title"), oldArticle1);
Article result2 = articleMapper.toArticleUsingExpressionMethod(new ArticleDTO("Updated article 2 title"), oldArticle2);

assertThat(result1.getReviewedBy()).isNull();
assertThat(result2.getReviewedBy()).isNull();
assertThat(result1.getTitle()).isEqualTo("Updated article 1 title");
assertThat(result2.getTitle()).isEqualTo("Updated article 2 title");
}

@Test
void givenArticleDTO_whenToArticleUsingIgnore_thenReturnsArticleWithNullStatus() {
Article oldArticle1 = new Article("ID-1", "John Doe");

Article result1 = articleMapper.toArticleUsingIgnore(new ArticleDTO("Updated article 1 title"), oldArticle1);

assertThat(result1.getReviewedBy()).isNull();
assertThat(result1.getTitle()).isEqualTo("Updated article 1 title");
}

@Test
void givenArticleDTO_whenToArticleUsingAfterMapping_thenReturnsArticleWithNullStatus() {
Article oldArticle1 = new Article("ID-1", "John Doe");

Article result1 = articleMapper.toArticleUsingAfterMapping(new ArticleDTO("Updated article 1 title"), oldArticle1);

assertThat(result1.getReviewedBy()).isNull();
assertThat(result1.getTitle()).isEqualTo("Updated article 1 title");
}

@Test
void givenArticleDTO_whenToArticleUsingQualifiedBy_thenReturnsArticleWithNullStatus() {
Article result1 = articleMapper.toArticleUsingQualifiedBy(new ArticleDTO("Updated article 1 title"), new Article("ID-1", "John Doe"));

assertThat(result1.getReviewedBy()).isNull();
assertThat(result1.getTitle()).isEqualTo("Updated article 1 title");
}

@Test
void givenArticleDTO_whenToReviewableUsingMapper_thenReturnsArticleWithNullStatus() {
Reviewable result1 = reviewableMapper.toReviewable(new ArticleDTO("Updated article 1 title"));
Reviewable result2 = reviewableMapper.toReviewable(new WeeklyNewsDTO());

assertThat(result1).isInstanceOf(Article.class);
assertThat(result2).isInstanceOf(WeeklyNews.class);
assertThat(result1.getReviewedBy()).isNull();
assertThat(result2.getReviewedBy()).isNull();
}
}