JAVA对象转换利器—MapStruct

一、背景

我们在使用JAVA开发项目的过程中经常遇到很多对象转换的场景，例如 DO、DTO、BO、AO、VO等对象间的转换，之前自己都是手写，最近发现了一个好用的工具—MapStruct，下面推荐给大家。

二、MapStruct

1. git地址：

https://github.com/mapstruct/mapstruct?spm=ata.13261165.0.0.49823fc0pcr5Q9

2.示例：

下面有两个类，需要进行转换：

public class Car {
 
    private String make;
    private int numberOfSeats;
    private CarType type;
 
    //constructor, getters, setters etc.
}


public class CarDto {
 
    private String make;
    private int seatCount;
    private String type;
 
    //constructor, getters, setters etc.
}

(1)手写实现

public class CarConvertor {

public static Car CarDtoToCar(CarDto carDto) {
   if (carDto == null){
      return null;
   }
   Car car = new Car();
   car.setMake(carDto.getMake());
   car.setNumberOfSeats(carDto.getSeatCount());
   car.setType(carDto.getType());
   return car;
}

(2)MapStruct 实现

@Mapper 
public interface CarMapper {
 
    CarMapper INSTANCE = Mappers.getMapper( CarMapper.class ); 
 
    @Mapping(source = "seatCount", target = "numberOfSeats")
    Car carDtoToCar(CarDto carDto); 
}

 public static void main(String[] args) {
    CarDto carDto = new CarDto( "Morris", 5, CarType.SEDAN );
    Car car = CarMapper.INSTANCE.carDtoToCar(carDto);
    System.out.println(Json.toString(car));
    }