EasyExcel转换为枚举、json等其他类型失败

easyexcel能够解决常规的类型转换问题，但是如果我们有特殊类型：枚举、json等等，往往就会报错，需要配置额外的转换器

easyexcel提供了自定义的转换器接口

interface Converter<T>

其中，我们主要需要重写下述内容

提供一个java中的对象类型，返回java支持的类

default Class<?> supportJavaTypeKey() {
        throw new UnsupportedOperationException("The current operation is not supported by the current converter.");
    }

返回Excel支持的对象的枚举

default CellDataTypeEnum supportExcelTypeKey() {
        throw new UnsupportedOperationException("The current operation is not supported by the current converter.");
    }

将Excel对象转为java对象（后续两个值）

    default T convertToJavaData(ReadCellData<?> cellData, ExcelContentProperty contentProperty,
        GlobalConfiguration globalConfiguration) throws Exception {
        throw new UnsupportedOperationException("The current operation is not supported by the current converter.");
    }

将java对象转为Excel对象

    default WriteCellData<?> convertToExcelData(T value, ExcelContentProperty contentProperty,
        GlobalConfiguration globalConfiguration) throws Exception {
        throw new UnsupportedOperationException("The current operation is not supported by the current converter.");
    }

 

以枚举类型为例：

public class GEnumsConverter implements Converter<GEnum> {

    @Override
    public Class<GEnum> supportJavaTypeKey() {
        return GenderEnum.class;
    }

    @Override
    public CellDataTypeEnum supportExcelTypeKey() {
        return CellDataTypeEnum.NUMBER;
    }

    @Override
    public GEnum convertToJavaData(ReadCellData<?> cellData, ExcelContentProperty contentProperty, GlobalConfiguration globalConfiguration) {
        // 将Excel数字转换为G
        Integer value = cellData.getNumberValue().intValue();
        for (GEnum g : GEnum.values()) {
            if (g.getValue().equals(value)) {
                return gender;
            }
        }
        throw new IllegalArgumentException("不支持的性别值: " + value);
    }

    @Override
    public WriteCellData<?> convertToExcelData(GEnum value, ExcelContentProperty contentProperty,
                                              GlobalConfiguration globalConfiguration) throws Exception {
        if (value == null) {
            return new WriteCellData<>("");
        }
        WriteCellData<Integer> cellData = new WriteCellData<>(value.getValue().toString());
        cellData.setType(CellDataTypeEnum.NUMBER);
        return cellData;
    }

}