在具有相同属性名称的不同数据类型上使用ModelMapper [英] Using ModelMapper on different data types with same attribute name

问题描述

我有两个类，分别是 Animal & AnimalDto
我想使用 ModelMapper 将Entity转换为DTO，反之亦然.
但是对于一些名称相似的属性，这些类应该具有不同的数据类型.
我该如何实现?

I have two classes say Animal & AnimalDto
I want to use ModelMapper to convert Entity to DTO and vice verca.
But the classes are supposed to have different data types for a few attributes having similar name.
How do I achieve this?

Animal.java

public class Animal {    
    int category;    
    String color;    
    int age;
}    
 

AnimalDto.java

public class AnimalDto {    
    String category;    
    int color;    
    int age;
}

---

目前，我正在手动进行这样的转换:

---

currently I'm manually transforming as such:

class AnimalTransformer {
    private static Category[] categories = Category.values();    
    private static Color[] colors = Color.values();    

    animalEntityToDto(Animal animal) {
          AnimalDto animalDto = new AnimalDto();    
          animalDto.setAge(animal.getAge());
          animalDto.setCategory(categories[animal.getCategory()].toString());
          animalDto.setColor(Color.valueOf(animal.getColor()).ordinal());
    }

    animalDtoToEntity(AnimalDto animalDto) {
          Animal animal = new Animal();    
          animal.setAge(animalDto.getAge());
          animal.setCategory(Category.valueOf(animalDto.getCategory()).ordinal());
          animal.setColor(colors[animalDto.getColor()].toString());
    }
}

推荐答案

您提供的示例在流畅度方面可能不是模型映射器的最佳部分，特别是因为转换具有某些特殊困难的 enum 谈到使用泛型.

The example you presented might not be the best part of model mapper in fluency especially because converting enums that have some special difficulties what comes to using generics.

无论如何，使用 Converter 或通常使用 AbstractConverter 都是可能的.

Anyway this is possible with Converter or usually AbstractConverter.

您没有提供枚举示例，所以我创建了最简单的枚举示例:

You did not provide examples of your enums so I create most simple example enums:

enum Color {
    PINK;
}

和

enum Category {
    MAMMAL;
}

要将整数 Animal.category 转换为 String AnimalDto.category ，转换器应类似于:

To convert Integer Animal.category to String AnimalDto.category, a converter could be like:

public class CategoryToStringConverter extends AbstractConverter<Integer, String> {
    @Override
    protected String convert(Integer source) {
        return Category.values()[source].toString();
    }
}

并要将 String Animal.color 转换为 Integer AnimalDto.category ，转换器应类似于:

And to convert String Animal.color to Integer AnimalDto.category, a converter could be like:

public class ColorToOrdinalConverter extends AbstractConverter<String, Integer> {
    @Override
    protected Integer convert(String source) {
        return Color.valueOf(source).ordinal();
    }
}

用法将是:

mm.createTypeMap(Animal.class, AnimalDto.class).addMappings(mapper -> {
    mapper.using(new CategoryToStringConverter()).map(Animal::getCategory, 
        AnimalDto::setCategory);
    mapper.using(new ColorToOrdinalConverter()).map(Animal::getColor, 
        AnimalDto::setColor);
});

这是从 Animal 转换为 AnimalDto 的一部分.反之亦然，转换当然需要它自己的映射，在这里我不介绍它，因为我认为要点很清楚.

This is the part of converting from Animal to AnimalDto. Converting vice versa of course needs mappings of its own which I do not present here because I think the point came clear.

对于一个类，您现在的做法可能会更好，但是如果您需要转换 Category &在这样的许多地方 Color ，那么您应该考虑使用可重复使用的转换器.

For one class the way you do it now might be better but if you need to convert Category & Color in many places like this then you should consider using converters that are reusable.

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