mapstruct的用法之qualifiedByName示例详解
时间：2022-07-08 10:29:19|栏目：JAVA代码|点击： 次
qualifiedByName的意思就是使用这个Mapper接口中的指定的默认方法去处理这个属性的转换，而不是简单的get set。网上一直没找到…
可用于格式化小数位等，在po转换为vo时就已格式化小数位完成，所以不必单独再写代码处理小数位。
1 引用pom1 ，能正常使用mapstruct的注解，但不会生成Impl类
<!-- https://mvnrepository.com/artifact/org.mapstruct/mapstruct-jdk8 -->
<dependency>
<groupId>org.mapstruct</groupId>
<artifactId>mapstruct-jdk8</artifactId>
<version>1.2.0.Final</version>
</dependency>
引用pom2 才会生成Impl类
2 定义ConvertMapper
package com.weather.weatherexpert.common.model.mapper;
import com.weather.weatherexpert.common.model.po.AreaPO;
import com.weather.weatherexpert.common.model.vo.AreaVO;
import org.mapstruct.MapMapping;
import org.mapstruct.Mapper;
import org.mapstruct.Mapping;
import org.mapstruct.Named;
import org.mapstruct.factory.Mappers;
import java.text.DecimalFormat;
/**
* <p>Title: </p>
* <p>Description: </p>
*
*/
@Mapper
public interface ConvertMapper {
ConvertMapper INSTANCE = Mappers.getMapper(ConvertMapper.class);
@Mapping(source = "pm25", target = "pm25", qualifiedByName = "formatDoubleDef")
AreaVO areaPO2areaVO(AreaPO areaPO);
@Named("formatDoubleDef")//需要起个名字，不然报错,可以与方法名一致，当然也可以不一致
default Double formatDouble(Double source) {
DecimalFormat decimalFormat = new DecimalFormat("0.00");//小数位格式化
if (source == null) {
source = 0.0;
}
return Double.parseDouble(decimalFormat.format(source));
}
}
3 定义源类和目标类
public class AreaPO {
private String cityName;
private Integer haveAir;
private Double pm25;
private String pm10Str;
............
}
public class AreaVO {
private String cityName;
private Integer haveAir;
private Double pm25;
private String pm25Str;
private Double pm10;
......
}
4 看生成的Impl类ConvertMapperImpl
package com.weather.weatherexpert.common.model.mapper;
import com.weather.weatherexpert.common.model.po.AreaPO;
import com.weather.weatherexpert.common.model.vo.AreaVO;
public class ConvertMapperImpl implements ConvertMapper {
public ConvertMapperImpl() {
}
public AreaVO areaPO2areaVO(AreaPO areaPO) {
if (areaPO == null) {
return null;
} else {
AreaVO areaVO = new AreaVO();
areaVO.setPm25(this.formatDouble(areaPO.getPm25()));
areaVO.setCityName(areaPO.getCityName());
areaVO.setHaveAir(areaPO.getHaveAir());
return areaVO;
}
}
5 测试
AreaPO areaPO = new AreaPO("忻州", 1, 1.256879);
AreaVO areaVO =
ConvertMapper.INSTANCE.areaPO2areaVO(areaPO);
logger.info("JSON.toJSONString(areaVO):" + JSON.toJSONString(areaVO));
输出：
JSON.toJSONString(areaVO):{“cityName”:“忻州”,“haveAir”:1,“pm25”:1.26}
关于@Target注解的使用可见：
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栏 目：JAVA代码
本文标题：mapstruct的用法之qualifiedByName示例详解
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