@Mapper注解基于mapStract 框架實現對象轉換：MapStract java bean 屬性轉換映射

引用轉自：org.mapstruct:mapstruct 包（@Mapper、@Mapping）的使用

依賴包：

<!--mapStruct依賴-->
<dependency><groupId>org.mapstruct</groupId><artifactId>mapstruct</artifactId><version>1.3.1.Final</version>
</dependency>
<dependency><groupId>org.mapstruct</groupId><artifactId>mapstruct-processor</artifactId><version>1.3.1.Final</version><scope>provided</scope>
</dependency><!--編譯插件-->
<build><plugins><plugin><groupId>org.apache.maven.plugins</groupId><artifactId>maven-compiler-plugin</artifactId><version>3.5.1</version><configuration><source>1.8</source><target>1.8</target><annotationProcessorPaths><path><groupId>org.mapstruct</groupId><artifactId>mapstruct-processor</artifactId><version>1.3.1.Final</version></path></annotationProcessorPaths></configuration></plugin></plugins>
</build>

常用注解：

注解	使用位置	描述
Mapper	適用在 類 接口 枚舉 上	進行類的映射
Mapping	適用在 方法 上	進行方法參數屬性的映射
MapMapping	適用在 方法 上	進行方法參數（Map類型）的映射
Mappings	適用在 方法 上	組合注解，可以標記多個Mapping

案例：

@Mapper(componentModel = "spring", unmappedTargetPolicy = ReportingPolicy.IGNORE)
public interface LogMapper {@Mappings({@Mapping(source = "id", target = "idDTO"),@Mapping(source = "realName", target = "realNameDTO"),@Mapping(source = "name", target = "nameDTO"),// 使用defaultValue@Mapping(target = "defaultValue", defaultValue = "morenzhi"),// 使用ignore@Mapping(target = "ignoreValue", ignore = true)})LogDTO convertToDTO(Log log);@Mappings({@Mapping(source = "idDTO", target = "id"),@Mapping(source = "realNameDTO", target = "realName"),@Mapping(source = "nameDTO", target = "name"),// 使用constant@Mapping(target = "address", constant = "1111"),// 使用ignore@Mapping(target = "ignoreValue", ignore = true)})Log covertToDO(LogDTO logDTO);// 有多個參數的時候，我們可以通過  參數.屬性 的方式進行轉換@Mappings({@Mapping(source = "log.id", target = "idDTO"),@Mapping(source = "log2.realName", target = "realNameDTO"),@Mapping(source = "log.name", target = "nameDTO"),})LogDTO convertToDTO2(Log log , Log2 log2);}//時間類型轉換示例
@Mapper(componentModel = "spring", unmappedTargetPolicy = ReportingPolicy.IGNORE)
public interface LogMapper {@Mappings({@Mapping(source = "id", target = "idDTO"),@Mapping(source = "realName", target = "realNameDTO"),@Mapping(source = "name", target = "nameDTO"),// dateFormat ：符合SimpleDataFormat的處理格式@Mapping(source = "dateStr", target = "date", dateFormat = "yyyy-MM-dd yy:mm:ss"),// numberFormat：符合DecimalFormat的處理格式@Mapping(source = "numberStr" , target = "number" , numberFormat = "$#.00")})LogDTO convertToDTO(Log log);}