Mapstruct 简明教程
MapStruct - Basic Mapping
使用 mapstruct 非常容易。要创建一个映射器,在接口上使用 org.mapstruct.Msapper 注释。
@Mapper
public interface StudentMapper {...}
现在在接口中创建一个转换方法。
@Mapper
public interface StudentMapper {
Student getModelFromEntity(StudentEntity student);
}
如果源和目标对象属性拥有相同名称,则会自动映射那些属性。如果属性名称不同,则请按照以下方式使用 @Mapping 注释 −
@Mapper
public interface StudentMapper {
@Mapping(target="className", source="classVal")
Student getModelFromEntity(StudentEntity student);
}
此处,className 是 Student 中的属性名称,a 目标对象和 classVal 是 StudentEntity 中的属性名称,a 源对象。
Example
在 Eclipse 中将项目映射打开为 Environment Setup 章中创建的内容。
使用以下代码创建 Student.java−
Student.java
package com.tutorialspoint.model;
public class Student {
private int id;
private String name;
private String className;
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;
}
}
使用以下代码创建 Student.java−
StudentEntity.java
package com.tutorialspoint.entity;
public class StudentEntity {
private int id;
private String name;
private String classVal;
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;
}
}
使用以下代码创建 StudentMapper.java −
StudentMapper.java
package com.tutorialspoint.mapper;
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")
Student getModelFromEntity(StudentEntity student);
@Mapping(target="classVal", source="className")
StudentEntity getEntityFromModel(Student student);
}
使用以下代码创建 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.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);
Student model = studentMapper.getModelFromEntity(entity);
assertEquals(entity.getClassVal(), model.getClassName());
assertEquals(entity.getName(), model.getName());
assertEquals(entity.getId(), model.getId());
}
@Test
public void testModelToEntity() {
Student model = new Student();
model.setId(1);
model.setName("John");
model.setClassName("X");
StudentEntity entity = studentMapper.getEntityFromModel(model);
assertEquals(entity.getClassVal(), model.getClassName());
assertEquals(entity.getName(), model.getName());
assertEquals(entity.getId(), model.getId());
}
}
运行以下命令以测试映射。
mvn clean test
Output
命令成功后。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.StudentMapperTest
Tests run: 2, Failures: 0, Errors: 0, Skipped: 0, Time elapsed: 0.004 sec
...