MapStruct是一个Java注解解释器，用于生成类型安全的Bean映射类。在使用时只需要定义一个映射器接口。在接口中声明所需要的映射方法，MapStruct会在编译期为我们生成此接口的实现类。

使用

依赖

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<!--mapstruct核心-->
<dependency>  
    <groupId>org.mapstruct</groupId>  
    <artifactId>mapstruct</artifactId>  
    <version>${mapstruct.version}</version>  
</dependency>

<!--mapstruct编译-->  
<dependency>  
    <groupId>org.mapstruct</groupId>  
    <artifactId>mapstruct-processor</artifactId>  
    <version>${mapstruct.version}</version>  
</dependency>

插件

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<plugin>  
    <groupId>org.apache.maven.plugins</groupId>  
    <artifactId>maven-compiler-plugin</artifactId>  
    <version>3.8.1</version>  
    <configuration>  
        <source>1.8</source>  
        <target>1.8</target>  
        <annotationProcessorPaths>  
            <path>  
                <groupId>org.projectlombok</groupId>  
                <artifactId>lombok</artifactId>  
                <version>${lombok.version}</version>  
            </path>  
            <path>  
                <groupId>io.github.linpeilie</groupId>  
                <artifactId>mapstruct-plus-processor</artifactId>  
                <version>${mapstruct-plus.version}</version>  
            </path>  
            <path>  
                <groupId>org.projectlombok</groupId>  
                <artifactId>lombok-mapstruct-binding</artifactId>  
                <version>${mapstruct-plus.lombok.version}</version>  
            </path>  
        </annotationProcessorPaths>  
    </configuration>  
</plugin>

定义接口形式用法

1.准备实体

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@Data  
@AllArgsConstructor  
@NoArgsConstructor  
@Builder  
public class Student implements Serializable {  
  
    private static final long serialVersionUID = 1L;  
  
    private Long id;  
  
    private String name;  
  
    private Integer age;  
  
    private String createBy;  
  
    private Date createTime;  
  
}

@Data  
public class StudentVO implements Serializable {  
  
    private static final long serialVersionUID = 1L;  
  
    private Long id;  
  
    private String name;  
  
    private Integer years;  
  
    private String createBy;  
  
    private Date createTime;  
  
}

2.转换接口

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@Mapper(imports = {DateUtils.class})  
public interface StudentConvert {  
  
    StudentConvert INSTANCE = Mappers.getMapper(StudentConvert.class);  
  
    @Mappings({  
            @Mapping(target = "createTime", expression = "java(DateUtils.getNowDate())"),  
            @Mapping(source = "age", target = "years"),  
    })  
    StudentVO convertStudent(Student student);  
}

3.工具类

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public class DateUtils {  
  
    public static Date getNowDate()  
    {  
        return new Date();  
    }  
  
}

5.自动生成的实现类

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@Generated(  
    value = "org.mapstruct.ap.MappingProcessor",  
    date = "2025-01-06T13:39:36+0800",  
    comments = "version: 1.5.5.Final, compiler: javac, environment: Java 1.8.0_181 (Oracle Corporation)"  
)  
public class StudentConvertImpl implements StudentConvert {  
  
    @Override  
    public StudentVO convertStudent(Student student) {  
        if ( student == null ) {  
            return null;  
        }  
  
        StudentVO studentVO = new StudentVO();  
  
        studentVO.setYears( student.getAge() );  
        studentVO.setId( student.getId() );  
        studentVO.setName( student.getName() );  
        studentVO.setCreateBy( student.getCreateBy() );  
  
        studentVO.setCreateTime( DateUtils.getNowDate() );  
  
        return studentVO;  
    }  
}

5.输出测试

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public static void main(String[] args) {
	Student student = Student.builder().id(1024L).age(25).createBy("xihai").name("悦彬先生").build();
	StudentVO studentVO = StudentConvert.INSTANCE.convertStudent(student);
	System.out.println(studentVO);
}

// 输出内容为：StudentVO(id=1024, name=悦彬先生, years=25, createBy=xihai, createTime=Mon Jan 06 14:18:00 CST 2025)

注解形式用法

1.准备实体类

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@Data  
@NoArgsConstructor  
@AllArgsConstructor  
@Builder  
@ApiModel(value = "设备信息")  
public class DeviceInfo implements Serializable {  
  
    private static final long serialVersionUID = 1L;  
  
    /**  
     * 主键id  
     */    private Long id;  
  
    /**  
     * 设备sn码  
     */  
    private String deviceSn;  
    /**  
     * 设备名称  
     */  
    private String deviceName;  
  
    /**  
     * 设备类型  
     */  
    private String deviceType;  
  
    /**  
     * 设备型号  
     */  
    private String deviceModel;  
  
    /**  
     * 设备图片  
     */  
    private String devicePic;  
  
    /**  
     * 设备厂商  
     */  
    private String manufacturer;  
  
    /**  
     * 固件版本  
     */  
    private String firmwareVersion;  
    /**  
     * 状态(停用0,启用1)  
     */    private Integer status;  
  
    /**  
     * 父设备id  
     */    private Long parent;  
  
    public void alarm(String name) {  
        System.out.println("方法被调用：" + name);  
    }  
  
}

@Data  
@AutoMapper(target = DeviceInfo.class)  
public class DeviceListVO {  
  
    @ApiModelProperty(value = "设备ID")  
    private Long id;  
  
    @ApiModelProperty(value = "设备sn码")  
    private String deviceSn;  
  
    @ApiModelProperty(value = "设备名称")  
    private String deviceName;  
  
    @ApiModelProperty(value = "设备类型")  
    private String deviceType;  
  
    @ApiModelProperty(value = "设备型号")  
    private String deviceModel;  
  
    @ApiModelProperty(value = "固件版本")  
    private String firmwareVersion;  
  
    @ApiModelProperty(value = "状态(停用0,启用1)")  
    private Integer status;  
  
}

2.转换工具

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@NoArgsConstructor(access = AccessLevel.PRIVATE)  
public class MapstructUtils {  
  
    private static final Converter CONVERTER = (Converter)SpringUtils.getBean(Converter.class);  
  
    /**  
     * 将 T 类型对象，转换为 desc 类型的对象并返回  
     *  
     * @param source 数据来源实体  
     * @param desc   描述对象 转换后的对象  
     * @return desc  
     */    public static <T, V> V convert(T source, Class<V> desc) {  
        if (ObjectUtil.isNull(source)) {  
            return null;  
        }  
        if (ObjectUtil.isNull(desc)) {  
            return null;  
        }  
        return CONVERTER.convert(source, desc);  
    }  
  
    /**  
     * 将 T 类型对象，按照配置的映射字段规则，给 desc 类型的对象赋值并返回 desc 对象  
     *  
     * @param source 数据来源实体  
     * @param desc   转换后的对象  
     * @return desc  
     */    public static <T, V> V convert(T source, V desc) {  
        if (ObjectUtil.isNull(source)) {  
            return null;  
        }  
        if (ObjectUtil.isNull(desc)) {  
            return null;  
        }  
        return CONVERTER.convert(source, desc);  
    }  
  
    /**  
     * 将 T 类型的集合，转换为 desc 类型的集合并返回  
     *  
     * @param sourceList 数据来源实体列表  
     * @param desc       描述对象 转换后的对象  
     * @return desc  
     */    public static <T, V> List<V> convert(List<T> sourceList, Class<V> desc) {  
        if (ObjectUtil.isNull(sourceList)) {  
            return null;  
        }  
        if (CollUtil.isEmpty(sourceList)) {  
            return CollUtil.newArrayList();  
        }  
        return CONVERTER.convert(sourceList, desc);  
    }  
  
    /**  
     * 将 Map 转换为 beanClass 类型的集合并返回  
     *  
     * @param map       数据来源  
     * @param beanClass bean类  
     * @return bean对象  
     */  
    public static <T> T convert(Map<String, Object> map, Class<T> beanClass) {  
        if (MapUtil.isEmpty(map)) {  
            return null;  
        }  
        if (ObjectUtil.isNull(beanClass)) {  
            return null;  
        }  
        return CONVERTER.convert(map, beanClass);  
    }  
  
}

3.进行转换

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@RestController  
public class MapStructController {  
  
    @GetMapping("/test")  
    public void test() {  
        DeviceInfo deviceInfo = new DeviceInfo(111L,"1f7a3af7-6b06-410b-a283-d8fc24e1acbb", "M30T-1", "M30T", "M30T", "url", "XIHAI", "1.0.0", 1, null);
        DeviceListVO vo = MapstructUtils.convert(deviceInfo, DeviceListVO.class);
        System.out.println(vo);
    }  
  
}
许可协议

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