在springboot3.4.4和jdk17环境下集成使用mapstruct

在springboot3.4.4和jdk17环境下集成使用mapstruct

MapStruct可以减少编码量，dto,entity相互转换时，自动生成set,get方法的调用。
源码地址：https://gitcode.com/qq_39339588/mapstruct.git

2025-04-21

一、maven依赖

<properties>
    <java.version>17</java.version>
    <maven.compiler.source>${java.version}</maven.compiler.source>
    <maven.compiler.target>${java.version}</maven.compiler.target>
    <org.projectlombok.version>1.18.16</org.projectlombok.version>
    <org.mapstruct.version>1.6.3</org.mapstruct.version>

</properties>
<!--mapStruct依赖-->
<!-- mapstruct  -->
<dependency>
    <groupId>org.mapstruct</groupId>
    <artifactId>mapstruct</artifactId>
    <version>${org.mapstruct.version}</version>
</dependency>
<!-- lombok dependency should not end up on classpath -->
<dependency>
    <groupId>org.projectlombok</groupId>
    <artifactId>lombok</artifactId>
    <version>${org.projectlombok.version}</version>
    <scope>provided</scope>
</dependency>

  <build>
        <plugins>
              <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-compiler-plugin</artifactId>
                <version>3.8.1</version>
                <configuration>
                    <source>${java.version}</source>
                    <target>${java.version}</target>
                    <annotationProcessorPaths>
                        <path>
                            <groupId>org.mapstruct</groupId>
                            <artifactId>mapstruct-processor</artifactId>
                            <version>${org.mapstruct.version}</version>
                        </path>
                        <path>
                            <groupId>org.projectlombok</groupId>
                            <artifactId>lombok</artifactId>
                            <version>${org.projectlombok.version}</version>
                        </path>

                        <!-- additional annotation processor required as of Lombok 1.18.16 -->
                        <path>
                            <groupId>org.projectlombok</groupId>
                            <artifactId>lombok-mapstruct-binding</artifactId>
                            <version>0.2.0</version>
                        </path>
                    </annotationProcessorPaths>
                </configuration>
            </plugin>
        </plugins>
    </build>

建议安装插件 mapstruct support，按 ctrl + 鼠标左键 ，会跳转到参数对应的类

二、准备实体类

package space.goldchen.mapstruct.entity;

import lombok.Data;
import lombok.Getter;
import lombok.Setter;

/**
 *  对象1
 * @author 2021
 * @create 2025-04-18 16:41
 */
@Data
public class Pig {
    /**
     * id
     */
    private Long id;
    /**
     * 姓名
     */
    private String name;
    /**
     * 年龄
     */
    private Integer age;
    /**
     * 价格
     */
    private Double price;
}

package space.goldchen.mapstruct.entity;

import lombok.Data;

/**
 * @author 2021
 * @create 2025-04-18 16:50
 */
@Data
public class Person {
    private Long id;
    private String name;
}

三、准备DTO

package space.goldchen.mapstruct.dto;

import lombok.Data;

/**
 * @author 2021
 * @create 2025-04-18 16:44
 */
@Data
public class PigDto {
    private Long id;
    private String name;
    private Integer age;
}

package space.goldchen.mapstruct.dto;

import lombok.Data;

/**
 * @author 2021
 * @create 2025-04-18 16:46
 */
@Data
public class PersonDto {
    private Long idid;
    private String namename;
    private String fullName;
}

四、创建Mapper映射

1. 创建公用接口

package space.goldchen.mapstruct.mapper;

/**
 * @author 2021
 * @create 2025-04-21 09:17
 */

import java.util.List;

/**
 * 转换对象的属性名称一致时，可以省略Mappings的对应关系设置，使用泛型比较合适
 * mapstruct 公共类
 * <DTO,Entity>
 */
public interface BaseMapper<D, E> {

    /**
     * entity转 DTO
     *
     * @param entity
     * @return
     */
    D toDto(E entity);

    /**
     * DTO 转 entity
     *
     * @param dto
     * @return
     */
    E toEntity(D dto);

    /**
     * entity集合 转 DTO集合
     *
     * @param entityList
     * @return
     */
    List<D> toDto(List<E> entityList);

    /**
     * DTO集合 转 entity集合
     *
     * @param dtoList
     * @return
     */
    List<E> toEntity(List<D> dtoList);
}

2. 创建PigDtoMapper映射关系

@Mapper(componentModel = “spring”,unmappedTargetPolicy = ReportingPolicy.IGNORE)

package space.goldchen.mapstruct.mapper;

import org.mapstruct.Mapper;
import org.mapstruct.Mapping;
import org.mapstruct.Mappings;
import org.mapstruct.ReportingPolicy;
import space.goldchen.mapstruct.dto.PigDto;
import space.goldchen.mapstruct.entity.Pig;

/**
 * @author 2021
 * @create 2025-04-18 16:52
 */
@Mapper(componentModel = "spring",unmappedTargetPolicy = ReportingPolicy.IGNORE)
public interface PigDtoMapper extends BaseMapper<PigDto,Pig> {
    /**
     *  pig转为pigDto
     * @param pig
     * @return
     */
    @Mappings({
            // 属性名称一致时，可以省略
            @Mapping(source = "id", target = "id"),
            @Mapping(source = "name", target = "name"),
            @Mapping(source = "age", target = "age")
    })
    public PigDto toDto(Pig pig);

}

3. 创建PersonMapper映射关系

package space.goldchen.mapstruct.mapper;

import org.mapstruct.Mapper;
import org.mapstruct.Mapping;
import org.mapstruct.Mappings;
import org.mapstruct.ReportingPolicy;
import space.goldchen.mapstruct.dto.PersonDto;
import space.goldchen.mapstruct.entity.Person;

/**
 * @author 2021
 * @create 2025-04-21 11:24
 */
@Mapper(componentModel = "spring",unmappedTargetPolicy = ReportingPolicy.IGNORE)
public interface PersonMapper extends BaseMapper<PersonDto, Person>{

    @Mappings({
            // 属性名称一致时，可以省略
            @Mapping(source = "id", target = "idid"),
            @Mapping(source = "name", target = "namename"),
            @Mapping(source = "name", target = "fullName")
    })
    @Override
    PersonDto toDto(Person entity);
}

五、调用测试

package space.goldchen.mapstruct;

import ch.qos.logback.classic.Logger;
import jakarta.annotation.Resource;
import lombok.extern.slf4j.Slf4j;
import org.junit.jupiter.api.DisplayName;
import org.junit.jupiter.api.Test;
import org.springframework.boot.test.context.SpringBootTest;
import space.goldchen.mapstruct.dto.PersonDto;
import space.goldchen.mapstruct.dto.PigDto;
import space.goldchen.mapstruct.entity.Person;
import space.goldchen.mapstruct.entity.Pig;
import space.goldchen.mapstruct.mapper.PersonMapper;
import space.goldchen.mapstruct.mapper.PigDtoMapper;

@SpringBootTest
@Slf4j
class MapStructApplicationTests {
    @Resource
    private PigDtoMapper pigDtoMapper;
    @Resource
    private PersonMapper personMapper;

    @DisplayName("测试Pig转PigDto")
    @Test
    void testPigDtoMapper() {
        Pig pig = new Pig();
        pig.setId(1L);
        pig.setName("pig");
        pig.setAge(2);
        pig.setPrice(100.0);
        PigDto pigDto = pigDtoMapper.toDto(pig);
        log.info("pigDto:{}", pigDto);
    }


    @DisplayName("测试Person转PersonDto")
    @Test
    void testPersonToPersonDto () {
        Person person = new Person();
        person.setId(2L);
        person.setName("我是personName");
        PersonDto personDto = personMapper.toDto(person);
        log.info("personDto:{}", personDto);
    }

}

七、更多细节

1. 设置默认值

@Mapping(source = "person.name",target = "personName",defaultValue = "默认值")

2. 使用表达式

// 目前java是唯一受支持的语言，达式必须以Java表达式的形式给出
// 注意： 这个属性不能与source()、defaultValue()、defaultExpression()、qualifiedBy()、qualifiedByName()或constant()一起使用。
@Mapping(target = "describe", source = "describe", defaultValue = "默认值")
@Mapping(target = "createTime",expression = "java(new java.util.Date())")
PersonDTO conver(Person person);

@Mapping(target = "created",expression = "java(cn.hutool.core.date.DateTime.now())")

3. 类中的子类转换

// uses 成员类，子类
@Mapper(componentModel = "spring", uses = {Log3InnerMapper.class},
        unmappedTargetPolicy = ReportingPolicy.IGNORE)
public interface Log3Mapper extends BaseMapper<Log3DTO, Log3> {

}

4. Map的转换

// MapMapping  map集合使用
@Mapper
 public interface SimpleMapper {
       @MapMapping(valueDateFormat = "dd.MM.yyyy")
       Map<String, String> longDateMapToStringStringMap(Map<Long, Date> source);
 }

5. 逆转换

// 使用注释`@InheritInverseConfiguration`表示方法应继承相应反向方法的反向配置
@Mapping(target = "age",source = "age", numberFormat = "#0.00")
PersonDTO conver(Person person);

@InheritInverseConfiguration
Person conver(PersonDTO dto);