@Data
public class ReqCustomerDailyImport {
    /**
     * 客户名称
     */
    @ExcelProperty(index = 0)
    private String customerName;
    /**
     * MIS编码
     */
    @ExcelProperty(index = 1)
    private String misCode;
    /**
     * 月度滚动额
     */
    @ExcelProperty(index = 3)
    private BigDecimal monthlyQuota;
    /**
     * 最新应收账款余额
     */
    @ExcelProperty(index = 4)
    private BigDecimal accountReceivableQuota;
    /**
     * 本月利率(年化）
     */
    @ExcelProperty(index = 5)
    private BigDecimal dailyInterestRate;
}

List<ReqCustomerDailyImport> reqCustomerDailyImports = EasyExcel.read(inputStream)
            // 这个转换是成全局的， 所有java为string,excel为string的都会用这个转换器。
            // 如果就想单个字段使用请使用@ExcelProperty 指定converter
            .registerConverter(new StringConverter())
            // 注册监听器，可以在这里校验字段
            .registerReadListener(new CustomerDailyImportListener())
            .head(ReqCustomerDailyImport.class)
            .sheet()
            .headRowNumber(2)
            .doReadSync();
}

public class CustomerDailyImportListener extends AnalysisEventListener {
    List misCodes = Lists.newArrayList();
    /**
     * 每解析一行，回调该方法
     * @param data
     * @param context
     */
    @Override
    public void invoke(Object data, AnalysisContext context) {
        String misCode = ((ReqCustomerDailyImport) data).getMisCode();
        if (StringUtils.isEmpty(misCode)) {
            throw new RuntimeException(String.format("第%s行MIS编码为空，请核实", context.readRowHolder().getRowIndex() + 1));
        }
        if (misCodes.contains(misCodes)) {
            throw new RuntimeException(String.format("第%s行MIS编码已重复，请核实", context.readRowHolder().getRowIndex() + 1));
        } else {
            misCodes.add(misCode);
        }
    }
    /**
     * 出现异常回调
     * @param exception
     * @param context
     * @throws Exception
     */
    @Override
    public void onException(Exception exception, AnalysisContext context) throws Exception {
        // ExcelDataConvertException:当数据转换异常的时候，会抛出该异常，此处可以得知第几行，第几列的数据
        if (exception instanceof ExcelDataConvertException) {
            Integer columnIndex = ((ExcelDataConvertException) exception).getColumnIndex() + 1;
            Integer rowIndex = ((ExcelDataConvertException) exception).getRowIndex() + 1;
            String message = "第" + rowIndex + "行，第" + columnIndex + "列" + "数据格式有误，请核实";
            throw new RuntimeException(message);
        } else if (exception instanceof RuntimeException) {
            throw exception;
        } else {
            super.onException(exception, context);
        }
    }
    /**
     * 解析完全部回调
     * @param context
     */
    @Override
    public void doAfterAllAnalysed(AnalysisContext context) {
        misCodes.clear();
    }
}

public class StringConverter implements Converter<String> {
    @Override
    public Class supportJavaTypeKey() {
        return String.class;
    }
    @Override
    public CellDataTypeEnum supportExcelTypeKey() {
        return CellDataTypeEnum.STRING;
    }
    /**
     * 将excel对象转成Java对象，这里读的时候会调用
     *
     * @param cellData            NotNull
     * @param contentProperty     Nullable
     * @param globalConfiguration NotNull
     * @return
     */
    @Override
    public String convertToJavaData(CellData cellData, ExcelContentProperty contentProperty,
                                    GlobalConfiguration globalConfiguration) {
        return "自定义：" + cellData.getStringValue();
    }
    /**
     * 将Java对象转成String对象，写出的时候调用
     *
     * @param value
     * @param contentProperty
     * @param globalConfiguration
     * @return
     */
    @Override
    public CellData convertToExcelData(String value, ExcelContentProperty contentProperty,
                                       GlobalConfiguration globalConfiguration) {
        return new CellData(value);
    }
}