From 8b688e4e4098d2ef0c27a0a83a96898e1fb4c623 Mon Sep 17 00:00:00 2001
From: mdabrowski-eu <57441874+mdabrowski-eu@users.noreply.github.com>
Date: Mon, 10 Apr 2023 07:59:12 +0200
Subject: [PATCH] BAEL-6216 Use Mapper in Another Mapper with Mapstruct and
 Java (#13802)

---
 .../java/com/baeldung/dto/ArticleDTO.java     | 12 +++++
 .../java/com/baeldung/entity/Article.java     | 12 +++++
 .../com/baeldung/mapper/ArticleMapper.java    | 20 ++++++++
 .../mapper/ArticleUsingPersonMapper.java      | 16 ++++++
 .../mapper/ArticleMapperUnitTest.java         | 49 +++++++++++++++++++
 5 files changed, 109 insertions(+)
 create mode 100644 mapstruct/src/main/java/com/baeldung/dto/ArticleDTO.java
 create mode 100644 mapstruct/src/main/java/com/baeldung/entity/Article.java
 create mode 100644 mapstruct/src/main/java/com/baeldung/mapper/ArticleMapper.java
 create mode 100644 mapstruct/src/main/java/com/baeldung/mapper/ArticleUsingPersonMapper.java
 create mode 100644 mapstruct/src/test/java/com/baeldung/mapper/ArticleMapperUnitTest.java

diff --git a/mapstruct/src/main/java/com/baeldung/dto/ArticleDTO.java b/mapstruct/src/main/java/com/baeldung/dto/ArticleDTO.java
new file mode 100644
index 0000000000..708167de94
--- /dev/null
+++ b/mapstruct/src/main/java/com/baeldung/dto/ArticleDTO.java
@@ -0,0 +1,12 @@
+package com.baeldung.dto;
+
+import lombok.Getter;
+import lombok.Setter;
+
+@Getter
+@Setter
+public class ArticleDTO {
+    private int id;
+    private String name;
+    private PersonDTO author;
+}
diff --git a/mapstruct/src/main/java/com/baeldung/entity/Article.java b/mapstruct/src/main/java/com/baeldung/entity/Article.java
new file mode 100644
index 0000000000..4aff8f4166
--- /dev/null
+++ b/mapstruct/src/main/java/com/baeldung/entity/Article.java
@@ -0,0 +1,12 @@
+package com.baeldung.entity;
+
+import lombok.Getter;
+import lombok.Setter;
+
+@Getter
+@Setter
+public class Article {
+    private int id;
+    private String name;
+    private Person author;
+}
diff --git a/mapstruct/src/main/java/com/baeldung/mapper/ArticleMapper.java b/mapstruct/src/main/java/com/baeldung/mapper/ArticleMapper.java
new file mode 100644
index 0000000000..b5b47f6b3b
--- /dev/null
+++ b/mapstruct/src/main/java/com/baeldung/mapper/ArticleMapper.java
@@ -0,0 +1,20 @@
+package com.baeldung.mapper;
+
+import com.baeldung.dto.ArticleDTO;
+import com.baeldung.dto.PersonDTO;
+import com.baeldung.entity.Article;
+import com.baeldung.entity.Person;
+import org.mapstruct.Mapper;
+import org.mapstruct.factory.Mappers;
+
+@Mapper
+public interface ArticleMapper {
+    
+    ArticleMapper INSTANCE = Mappers.getMapper(ArticleMapper.class);
+    
+    ArticleDTO articleToArticleDto(Article article);
+
+    default PersonDTO personToPersonDto(Person person) {
+        return Mappers.getMapper(PersonMapper.class).personToPersonDTO(person);
+    }
+}
diff --git a/mapstruct/src/main/java/com/baeldung/mapper/ArticleUsingPersonMapper.java b/mapstruct/src/main/java/com/baeldung/mapper/ArticleUsingPersonMapper.java
new file mode 100644
index 0000000000..c1ea0797ed
--- /dev/null
+++ b/mapstruct/src/main/java/com/baeldung/mapper/ArticleUsingPersonMapper.java
@@ -0,0 +1,16 @@
+package com.baeldung.mapper;
+
+import com.baeldung.dto.ArticleDTO;
+import com.baeldung.dto.PersonDTO;
+import com.baeldung.entity.Article;
+import com.baeldung.entity.Person;
+import org.mapstruct.Mapper;
+import org.mapstruct.factory.Mappers;
+
+@Mapper(uses = PersonMapper.class)
+public interface ArticleUsingPersonMapper {
+
+    ArticleUsingPersonMapper INSTANCE = Mappers.getMapper(ArticleUsingPersonMapper.class);
+
+    ArticleDTO articleToArticleDto(Article article);
+}
diff --git a/mapstruct/src/test/java/com/baeldung/mapper/ArticleMapperUnitTest.java b/mapstruct/src/test/java/com/baeldung/mapper/ArticleMapperUnitTest.java
new file mode 100644
index 0000000000..2470915a01
--- /dev/null
+++ b/mapstruct/src/test/java/com/baeldung/mapper/ArticleMapperUnitTest.java
@@ -0,0 +1,49 @@
+package com.baeldung.mapper;
+
+import com.baeldung.dto.ArticleDTO;
+import com.baeldung.dto.CarDTO;
+import com.baeldung.entity.Article;
+import com.baeldung.entity.Car;
+import com.baeldung.entity.Person;
+import org.junit.Test;
+
+import static org.junit.Assert.assertEquals;
+
+public class ArticleMapperUnitTest {
+
+    @Test
+    public void givenArticle_whenMaps_thenProducesCorrectDto() {
+        
+        Article entity  = new Article();
+        entity.setId(1);
+        entity.setName("Mapstruct Mapping");
+        Person author = new Person();
+        author.setId("1");
+        author.setName("John");
+        entity.setAuthor(author);
+
+        ArticleDTO articleDTO = ArticleMapper.INSTANCE.articleToArticleDto(entity);
+
+        assertEquals(articleDTO.getId(), entity.getId());
+        assertEquals(articleDTO.getName(), entity.getName());
+        assertEquals(articleDTO.getAuthor().getName(), entity.getAuthor().getName());
+    }
+
+    @Test
+    public void givenArticle_whenMapsWithUses_thenProducesCorrectDto() {
+
+        Article entity  = new Article();
+        entity.setId(1);
+        entity.setName("Mapstruct Mapping");
+        Person author = new Person();
+        author.setId("1");
+        author.setName("John");
+        entity.setAuthor(author);
+
+        ArticleDTO articleDTO = ArticleUsingPersonMapper.INSTANCE.articleToArticleDto(entity);
+
+        assertEquals(articleDTO.getId(), entity.getId());
+        assertEquals(articleDTO.getName(), entity.getName());
+        assertEquals(articleDTO.getAuthor().getName(), entity.getAuthor().getName());
+    }
+}