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枚举的组合和接口实现

问题描述​

项目最初定义了一个枚举类，几乎是把所有类型的枚举全部放到这个类里面，类似下面这种，通过type区分枚举的类型，初期这么设计，应该是为了对外提供一个字典查询的接口。后面的问题，当然就是这个类越来越大，于是打算拆分。

public enum AllDicEnum {
    DOG(1, "🐕", "animal"),
    CAT(2,"neko","animal"),
    APPLE(1, "苹果", "fruit");
    private final int value;
    private final String name;
    private final String type;
    
    public static List<AllDicEnum> findByType(String type) {
        List<AllDicEnum> list = new ArrayList<>();
        for (AllDicEnum allDicEnum : values()) {
            if (allDicEnum.type.equals(type)) {
                list.add(allDicEnum);
            }
        }
        return list;
    }
}

思路​

  1. 首先，把枚举类拆分成多个，比如，animal，fruit，plant等。
  2. 想保证拆分出来的枚举的字段自由定义。

解决​

  1. 创建接收枚举的对象
@Data
public class DicEnumVO {
    private Object value;
    private String name;
}
  1. 定义接口，通过code和desc生成枚举VO
public interface DicEnumInterface {

    Object getCode();

    String getDesc();

    default DicEnumVO getResourceDicStrVO() {
        DicEnumVO resourceDicVO = new DicEnumVO();
        resourceDicVO.setValue(getCode());
        resourceDicVO.setName(getDesc());
        return resourceDicVO;
    }


    static <E extends DicEnumInterface> List<DicEnumVO> getDicVO(Class<E> enumClass) {
        List<DicEnumVO> list = new ArrayList<>();
        for (E enumConstant : enumClass.getEnumConstants()) {
            DicEnumVO resourceDicStrVO = enumConstant.getResourceDicStrVO();
            if (resourceDicStrVO != null)
                list.add(resourceDicStrVO);
        }
        return list;
    }
}

  1. 将枚举类拆分并实现DicEnumInterface,可以自由定义字段，只要实现getCode和getDesc，或者重写getResourceDicStrVO
@Getter
public enum AnimalEnum implements DicEnumInterface{

    DOG(1, "🐕"),
    CAT(2,"neko"),
    ;

    private final int value;
    private final String name;

    AnimalEnum(int value, String name) {
        this.value = value;
        this.name = name;
    }

    @Override
    public Object getCode() {
        return this.value;
    }

    @Override
    public String getDesc() {
        return this.name;
    }
}

  1. 最后统一收集拆分出来的枚举
@Getter
public enum AllDicEnum {

    animal("animal","动物",AnimalEnum.class)
    ;
    /* 字典类型 */
    private final String type;
    private final String desc;
    private final Class<? extends DicEnumInterface> dicEnumInterface;

    AllDicEnum(String type, String desc, Class<? extends DicEnumInterface> dicEnumInterface) {
        this.type = type;
        this.desc = desc;
        this.dicEnumInterface = dicEnumInterface;
    }

    public static List<DicEnumVO> findByType(String type) {
        List<DicEnumVO> list = new ArrayList<>();
        for (AllDicEnum allDicEnum : values()) {
            if (allDicEnum.getType().equals(type)) {
                list = DicEnumInterface.getDicVo(allDicEnum.getDicEnumInterface());
            } else if (type.equals("all")) {
                list.addAll(DicEnumInterface.getDicVo(allDicEnum.getDicEnumInterface()));
            }
        }
        return list;
    }

    public static void main(String[] args) {
        System.out.println(findByType("animal"));
    }
}