MapStruct 工具使用(ignore，expression，qualifiedByName)

1.pom坐标

<!--mapstruct start-->
<dependency>
    <groupId>org.mapstruct</groupId>
    <artifactId>mapstruct</artifactId>
    <version>1.4.2.Final</version>
</dependency>
<dependency>
    <groupId>org.mapstruct</groupId>
    <artifactId>mapstruct-processor</artifactId>
    <version>1.4.2.Final</version>
</dependency>
<!--mapstruct end-->

2.使用

@Data
@TableName("t_order")
public class Order {

    @TableId(value = "order_id")
    private Long orderId;

    @TableField(value = "price")
    private BigDecimal price;

    @TableField(value = "user_id")
    private Long userId;

    @TableField(value = "status")
    private String status;

    private LocalDateTime start;

    private String generalField;
}

package com.wangguo.converter;


import com.wangguo.dto.OrderDto;
import com.wangguo.entity.Order;
import org.mapstruct.Mapper;
import org.mapstruct.Mapping;
import org.mapstruct.Named;
import org.mapstruct.factory.Mappers;

import java.math.BigDecimal;
import java.text.SimpleDateFormat;
import java.time.LocalTime;

/**
 * 1.常规的映射使用 @Mapping(target = "field", source = "generalField") 字段名不同
 * 2.expression 的使用 expression = "java(expression)"
 *  	2.1 expression 可以写相应的表达式
 *  	2.2 如果需要需要引入相应的类 在imports中引入
 * 3. qualifiedByName的使用
 *  	3.1 @Named() 注解定义方法 在相应的Converter类中
 *  	3.2 对应的方法名在 @Mapping中正常引用
 *  	3.3 其中方法中的参数来源于source，如我写的例子。因为方法中引用的是（Order order） 所以source=“order”
 * 4.ignore的使用 target中不映射source中的值
 */

@Mapper(imports = {LocalTime.class, SimpleDateFormat.class})
public interface OrderConverter {

    OrderConverter INSTANCE = Mappers.getMapper(OrderConverter.class);

    @Mapping(target = "field", source = "generalField")
    //@Mapping(target = "start", expression = "java(order.getStart()!= null ? order.getStart().withHour(23).withMinute(59).withSecond(59).withNano(0): null )")
    @Mapping(target = "start", expression = "java(order.getStart()!= null ? order.getStart().with(LocalTime.MAX).withNano(0): null )")
    @Mapping(target = "price", source = "order", qualifiedByName = "fillPrice")
    @Mapping(target = "status", ignore = true)
    OrderDto covert(Order order);

    @Named("fillPrice")
    default BigDecimal fillPrice(Order order) {
        return order.getPrice().add(new BigDecimal("2.0"));
    }
}

package com.wangguo;

import com.wangguo.converter.OrderConverter;
import com.wangguo.dto.OrderDto;
import com.wangguo.entity.Order;
import org.junit.jupiter.api.Test;
import org.springframework.boot.test.context.SpringBootTest;

import java.math.BigDecimal;
import java.time.LocalDateTime;

/**
 * Copyright 1968-2022 Midea Group,IT
 *
 * @author wangguo17
 * @create 2024/11/14
 * @description mapStruct的使用demo
 */
@SpringBootTest
public class ConvertTest {

    @Test
    public void convertDto() {
        Order order = new Order();
        order.setGeneralField("generaField");
        order.setStart(LocalDateTime.now());
        order.setPrice(new BigDecimal("2.0"));
        order.setStatus("status");

        System.out.println("order = " + order);
        OrderDto orderDto = OrderConverter.INSTANCE.covert(order);
        System.out.println("-------");
        System.out.println("orderDto = " + orderDto);

        /**
         * order = Order(orderId=null, price=2.0, userId=null, status=status, start=2024-11-14T10:51:01.935, generalField=generaField)
         * -------
         * orderDto = OrderDto(orderId=null, price=4.0, userId=null, status=null, start=2024-11-14T23:59:59, field=generaField)
         */

    }
}