MapStruct - 映射直接字段

MapStruct 可以轻松处理直接字段映射。例如，一个学生有 section 作为私有属性，一个学生实体有 section 作为公有属性。要同时进行获取/设置映射，那么属性应当设为公有。如果设为 public final，那么映射时只有获取方法可用。

现在创建一个映射器接口。将使用 `@InheritInverseConfiguration` 注解立即拷贝反向配置。

@Mapper
public interface StudentMapper {
   @Mapping(target="className", source="classVal")
   @Mapping(target="subject", source="subject.name")
   Student getModelFromEntity(StudentEntity studentEntity);
	
   @InheritInverseConfiguration
   StudentEntity getEntityFromModel(Student student);
}

示例

在 Eclipse 中打开在 “映射嵌套对象” 章节中更新的项目映射。

使用以下代码更新 `StudentEntity.java` −

`StudentEntity.java`

package com.tutorialspoint.entity;

public class StudentEntity {
   private int id;
   private String name;
   private String classVal;
   private SubjectEntity subject;
   public String section;
   public int getId() {
      return id;
   }
   public void setId(int id) {
      this.id = id;
   }
   public String getName() {
      return name;
   }
   public void setName(String name) {
      this.name = name;
   }
   public String getClassVal() {
      return classVal;
   }
   public void setClassVal(String classVal) {
      this.classVal = classVal;
   }
   public SubjectEntity getSubject() {
      return subject;
   }
   public void setSubject(SubjectEntity subject) {
      this.subject = subject;
   }
}

使用以下代码更新 `Student.java` −

`Student.java`

package com.tutorialspoint.model;

public class Student {
   private int id;
   private String name;
   private String className;
   private String subject;
   private String section;
   public int getId() {
      return id;
   }
   public void setId(int id) {
      this.id = id;
   }
   public String getName() {
      return name;
   }
   public void setName(String name) {
      this.name = name;
   }
   public String getClassName() {
      return className;
   }
   public void setClassName(String className) {
      this.className = className;
   }
   public String getSubject() {
      return subject;
   }
   public void setSubject(String subject) {
      this.subject = subject;
   }
   public String getSection() {
      return section;
   }
   public void setSection(String section) {
      this.section = section;
   }
}

使用以下代码更新 `StudentMapper.java` −

`StudentMapper.java`

package com.tutorialspoint.mapper;

import org.mapstruct.InheritInverseConfiguration;
import org.mapstruct.Mapper;
import org.mapstruct.Mapping;
import com.tutorialspoint.entity.StudentEntity;
import com.tutorialspoint.model.Student;

@Mapper
public interface StudentMapper {
   @Mapping(target="className", source="classVal")
   @Mapping(target="subject", source="subject.name")
   Student getModelFromEntity(StudentEntity studentEntity);

   @InheritInverseConfiguration
   StudentEntity getEntityFromModel(Student student);
}

使用以下代码更新 `StudentMapperTest.java` −

`StudentMapperTest.java`

package com.tutorialspoint.mapping;

import static org.junit.jupiter.api.Assertions.assertEquals;
import org.junit.jupiter.api.Test;
import org.mapstruct.factory.Mappers;
import com.tutorialspoint.entity.StudentEntity;
import com.tutorialspoint.entity.SubjectEntity;
import com.tutorialspoint.mapper.StudentMapper;
import com.tutorialspoint.model.Student;

public class StudentMapperTest {
   private StudentMapper studentMapper = Mappers.getMapper(StudentMapper.class);
   @Test
   public void testEntityToModel() {
      StudentEntity entity = new StudentEntity();
      entity.setClassVal("X");
      entity.setName("John");
      entity.setId(1);
      entity.section = "A";
      SubjectEntity subject = new SubjectEntity();
      subject.setName("Computer");
      entity.setSubject(subject);
      Student model = studentMapper.getModelFromEntity(entity);
      assertEquals(entity.getClassVal(), model.getClassName());
      assertEquals(entity.getName(), model.getName());
      assertEquals(entity.getId(), model.getId());
      assertEquals(entity.getSubject().getName(), model.getSubject());
      assertEquals(entity.section, model.getSection());	  
   }
   @Test
   public void testModelToEntity() {
      Student model = new Student();
      model.setId(1);
      model.setName("John");
      model.setClassName("X");
      model.setSubject("Science");
      model.setSection("A");
      StudentEntity entity = studentMapper.getEntityFromModel(model);

      assertEquals(entity.getClassVal(), model.getClassName());
      assertEquals(entity.getName(), model.getName());
      assertEquals(entity.getId(), model.getId());
      assertEquals(entity.getSubject().getName(), model.getSubject());
      assertEquals(entity.section, model.getSection());
   }
}

运行以下命令以测试映射。

mvn clean test

输出

命令成功。验证输出。

mvn clean test
[INFO] Scanning for projects...
...
[INFO] --- maven-surefire-plugin:2.12.4:test (default-test) @ mapping ---
[INFO] Surefire report directory: \mvn\mapping\target\surefire-reports

-------------------------------------------------------
 T E S T S
-------------------------------------------------------
Running com.tutorialspoint.mapping.DeliveryAddressMapperTest
Tests run: 1, Failures: 0, Errors: 0, Skipped: 0, Time elapsed: 0.005 sec
Running com.tutorialspoint.mapping.StudentMapperTest
Tests run: 2, Failures: 0, Errors: 0, Skipped: 0, Time elapsed: 0.002 sec

Results :

Tests run: 3, Failures: 0, Errors: 0, Skipped: 0
...