springboot+mybatis+枚举处理器的实现

if(status == 1){ // 时间一长，谁来告诉我1代表什么状态
    ...
}else if (status == 0){ // 0又代表什么状态
    ...
}
...

public interface KeyValueEnum {

    int getKey();

    String getValue();

}

public enum StatusEnum implements KeyValueEnum {

    ONLINE(1, "在线")，
    
    OFFLINE(0, "掉线");
    
    private int key;

    private String value;

    StatusEnum(int key, String value){
        this.key = key;
        this.value = value;
    }

    @Override
    public int getKey() {
        return key;
    }

    @Override
    public String getValue() {
        return value;
    }
}

@MappedTypes(value = {Status.class, Sex.class}) // 每增加一种枚举类型，就在此添加。
public class EnumTypeHandler<E extends KeyValueEnum> extends BaseTypeHandler<E> {

    private Class<E> type;
    private E[] enums;

    public EnumTypeHandler(Class<E> type){
        this.type = type;
        this.enums = type.getEnumConstants();
    }

    @Override
    public void setNonNullParameter(PreparedStatement preparedStatement, int i, KeyValueEnum keyValueEnum, JdbcType jdbcType) throws SQLException {
        preparedStatement.setInt(i, keyValueEnum.getKey());
    }

    @Override
    public E getNullableResult(ResultSet resultSet, int i) throws SQLException {
        int key = resultSet.getInt(i);
        return getEnum(key);
    }

    @Override
    public E getNullableResult(ResultSet resultSet, String s) throws SQLException {
        int key = resultSet.getInt(s);
        return getEnum(key);
    }

    @Override
    public E getNullableResult(CallableStatement callableStatement, int i) throws SQLException {
        int key = callableStatement.getInt(i);
        return getEnum(key);
    }

    private E getEnum(int key){
        for (E keyValue:
             enums) {
            if (keyValue.getKey() == key){
                return keyValue;
            }
        }
        return null;
    }
}

# application.yaml
mybatis:
  configuration:
    map-underscore-to-camel-case: true # 下划线转驼峰
  type-handlers-package: xxx.xxx.xxx.handler.mybatisTypeHandler # 配置刚才编辑的枚举处理器

@Data
public class device {

    private long id;

    private Status status;
}

public interface deviceMapper {

    @Results(id="aaa", value = {
            @Result(id = true, column = "id", property = "id"),
            @Result(column = "status", property = "status")
    })
    @Select("select * from device where id = #{id}")
    Device getDeviceById(long id);
}