MapStruct入门使用案例
以下是常用的使用举例，按照需求改动即可
@Data
public class UserDO{private int age;private String name;private Role role;private String date;
}@Data
public class UserDTO{private int dtoAge;private String dtoName;private Guest guest;private Date date;
}import org.mapstruct.*;
import org.mapstruct.factory.Mappers;@Mapper
public interface UserConvert{UserConvert INSTANCE = Mappers.getMapper(UserConvert.class);//方式1 返回值的方式UserDO DTOConvertDO(UserDTO dto);//方式2 参数加注解的方式void DTOConvertDO(UserDTO dto,@MappingTarget UserDO user)//自动忽略源对象为空的值@BeanMapping(nullValuePropertyMappingStrategy = NullValuePropertyMappingStrategy.IGNORE)UserDO DTOConvertDO(UserDTO dto);//resultType 指定返回目标类型，ignoreByDefault = true：在目标类型CarDto中忽略所有未映射的属性。//mappingControl = MappingControl.FILTER：如果存在未匹配的属性，过滤它们而不报告错误或警@BeanMapping(resultType = UserDO.class,ignoreByDefault = true, mappingControl = MappingControl.FILTER) UserDO DTOConvertDO(UserDTO dto);//非同名属性之间映射，指定dto的dtoName映射到Do中的name中@Mapping(source = "dtoName",target = "name")//条件映射，大于18岁进行映射赋值 @Mapping(condition = "java(dto.getDtoAge() >= 18)", target = "age")//忽略指定值映射 @Mapping(source="guest",ignore=true) void DTOConvertDO(UserDTO dto,@MappingTarget UserDO user)//非同名属性之间映射,包含其下的二层对象属性的赋值。dateFotmat指定时间格式@Mappings({@Mapping(source = "dtoName",target = "name"),@Mapping(source = "dtoAge",target = "age")@Mapping(source = "guest.name",target = "role.name")@Mapping(source = "date",target = "date",dateFotmat="yyyy-MM-dd")})void DTOConvertDO(UserDTO dto,@MappingTarget UserDO user)// 当为 null 时不赋值,可以一个个设置@Mapping(target = "dtoName", source = "name", defaultExpression = "java(null)")void DTOConvertDO(UserDTO dto,@MappingTarget UserDO user) //集合映射@MapMapping(valueDateFormat="yyyy-MM-dd")void DTOConvertDO(Map<String,Date> dto,@MappingTarget Map<String,String> map)
}注解作用：
@BeanMapping(nullValuePropertyMappingStrategy = NullValuePropertyMappingStrategy.IGNORE) : 忽略为null值的映射赋值
@MappingTarget : 指定赋值目标对象，赋值到哪去。
@Mapping(source = "dtoName",target = "name") : 指定映射关系，不同名的属性赋值，UserDTO下的dtoName赋值到UserDO下的name
@Mappings({
@Mapping(source = "dtoName",target = "name"),
@Mapping(source = "dtoAge",target = "age")
}) : 指定映射关系,多个时。
