[Enhancement] @ExcelProperty 开放注解范围

[ergehenmeng]

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• I searched in the issues and found nothing similar.

Motivation

目前ExcelPropery只能使用在Field, 导致如果字段是status这种, 只能手动增加转换器, 各类型不一样 就要增加很多转换器或者通过组合注解实现(太臃肿了), 希望开放ExcelPropery可以放在注解类上, 实现自定义注解, 用来翻译数据字典, 类似这样

@Target(ElementType.FIELD)
@Retention(RetentionPolicy.RUNTIME)
@Documented
@ExcelProperty(converter = DictConverter.class)
public @interface DictExcelProperty {
    
    /**
     * 导出时在Excel中显示的列名
     */
    String value() default "";
    
    /**
     * 字典类型，对应sys_dict_data表的dict_type字段
     * 例如：sys_user_sex, sys_job_status等
     */
    String dictType();
    
    /**
     * 本地数据字典转换 1=是,0=否
     */
    String translate() default "";
}

Solution

No response

Alternatives

No response

Anything else?

No response

Are you willing to submit a PR?

• I'm willing to submit a PR!

[bengbengbalabalabeng]

Hi, @ergehenmeng

To better understand the limitations you are currently facing, could you provide a simplified code example (including your current annotation usage, converter, etc.) that illustrates your current approach and the specific issues you’re encountering?

It will be much easier for us to discuss possible improvement directions :)

[bengbengbalabalabeng]

For the convenience of subsequent discussion, I have broken this requirement down into several more specific sub-issues to avoid mixing too many topics in a single Issue.

sub-issues:

1. Add composable annotations support
2. Add AnnotationAttributesAwareConverter interface implements custom composable annotation attributes callbacks. (Not yet)

[ergehenmeng]

谢谢回复,

目前我实现枚举类型的转换是通过 注解+转换器实现的 例子如下:

@Documented
@Target(ElementType.FIELD)
@Retention(RetentionPolicy.RUNTIME)
public @interface ExcelDesc {
}

@Slf4j
public class EnumExcelConverter implements Converter<Object> {

    private static final Map<Class<?>, Field> FIELD_MAP = new ConcurrentHashMap<>(32);

    @Override
    public Class<?> supportJavaTypeKey() {
        return Enum.class;
    }

    @Override
    public WriteCellData<?> convertToExcelData(Object value, ExcelContentProperty contentProperty, GlobalConfiguration globalConfiguration) {
        Field valueAs = this.getAnnotationField(contentProperty);
        return new WriteCellData<>(ReflectUtil.getFieldValue(value, valueAs).toString());
    }

    /**
     * 获取带有@ExcelDesc注解的属性
     *
     * @param contentProperty 原导出excel的字段
     * @return Field
     */
    private Field getAnnotationField(ExcelContentProperty contentProperty) {
        Class<?> fieldType = contentProperty.getField().getType();
        return FIELD_MAP.computeIfAbsent(fieldType, aClass -> {
            for (Field field : contentProperty.getField().getType().getDeclaredFields()) {
                ExcelDesc excelDesc = field.getAnnotation(ExcelDesc.class);
                if (excelDesc != null) {
                    return field;
                }
            }
            log.error("枚举类请使用@ExcelDesc标注要导出为Excel的字段 [{}]", fieldType);
            throw new BusinessException(ErrorCode.ENUM_SUPPORTED);
        });
    }
}

@Getter
@AllArgsConstructor
public enum Gender {

    /**
     * 未知
     */
    NONE(0, "未知"),

    /**
     * 男
     */
    MALE(1, "男"),

    /**
     * 女
     */
    FEMALE(2, "女");

    @JsonValue
    @EnumValue
    private final int value;
    
    @ExcelDesc 
    private final String name;

    @JsonCreator(mode = JsonCreator.Mode.DELEGATING)
    public static Gender of(@JsonProperty("value") Integer value) {
        if (value == null) {
            return null;
        }
        return Arrays.stream(Gender.values()).filter(auditState -> auditState.value == value)
                .findFirst().orElseThrow(() -> new BusinessException(ErrorCode.USER_TYPE_NULL));
    }

}

// 使用时 是这样的
@Schema(description = "性别 0:未知 1:男 2:女 ")
@ExcelProperty(value = "性别", index = 6, converter = EnumExcelConverter.class)
private Gender sex;

数据字典翻译类型的例子如下:

@Slf4j
public class DictConverter implements Converter<Integer> {

    @Override
    public Class<?> supportJavaTypeKey() {
        return Integer.class;
    }

    @Override
    public WriteCellData<?> convertToExcelData(Integer value, ExcelContentProperty contentProperty, GlobalConfiguration globalConfiguration) {
        ExcelDict dict = contentProperty.getField().getAnnotation(ExcelDict.class);
        if (dict == null) {
            return NumberUtils.formatToCellDataString(value, contentProperty);
        }
        SysDictService service = SpringUtil.getBean(SysDictService.class);
        String dictValue = service.getDictValue(dict.value(), value);
        if (dictValue == null) {
            log.warn("导出Excel解析数据字典为空 [{}] [{}]", dict.value(), value);
            return NumberUtils.formatToCellDataString(value, contentProperty);
        }
        return new WriteCellData<>(dictValue);
    }
}

@Documented
@Target(ElementType.FIELD)
@Retention(RetentionPolicy.RUNTIME)
public @interface ExcelDict {

    /**
     * 数据字典的key
     *
     * @return key
     */
    String value();
}

// 使用时

    @Schema(description = "反馈类型 数据字典: dict_feed_type")
    @ExcelDict(value = "dict_feed_type")
    @ExcelProperty(value = "反馈类型", index = 3, converter = DictConverter .class)
    private Integer feedType;

上述两种方式太过于繁琐, 且不够优雅, 我理想的方式是通过 实现自定义注解+自定义转换器, 把上面枚举+数据字典都能兼容即用 DictExcelProperty 注解代替 ExcelProperty注解

@Target(ElementType.FIELD)
@Retention(RetentionPolicy.RUNTIME)
@Documented
@ExcelProperty(converter = DictConverter.class)
public @interface DictExcelProperty {
    
    /**
     * 导出时在Excel中显示的列名
     */
    String value() default "";
    
    /**
     * 字典类型，对应sys_dict_data表的dict_type字段
     * 例如：sys_user_sex, sys_job_status等
     */
    String dictType();
    
    /**
     * 本地数据字典转换 1=是,0=否
     */
    String translate() default "";
    
   @AliasFor(annotation = ExcelProperty.class, index= "value")
    int index() default -1;

   @AliasFor(annotation = ExcelProperty.class, index= "order")
    int order() default Integer.MAX_VALUE;
}