比如这种情况，有那么部分时候，客户的要求那是相当的十分刁钻，平时的导出如果是用easyExcel的话，就需要写自定义拦截器再引入poi富文本来修改了。

新建类实现CellWriteHandler接口：

public class WriteHandlerStrategy implements CellWriteHandler {

    @Override
    public void beforeCellCreate(final WriteSheetHolder writeSheetHolder, final WriteTableHolder writeTableHolder,
                                 final Row row, final Head head, final Integer columnIndex,
                                 final Integer relativeRowIndex, final Boolean isHead) {

    }

    @Override
    public void afterCellCreate(final WriteSheetHolder writeSheetHolder, final WriteTableHolder writeTableHolder,
                                final Cell cell, final Head head, final Integer relativeRowIndex, final Boolean isHead) {

    }

    @Override
    public void afterCellDataConverted(final WriteSheetHolder writeSheetHolder, final WriteTableHolder writeTableHolder,
                                       final CellData cellData, final Cell cell, final Head head,
                                       final Integer relativeRowIndex, final Boolean isHead) {

    }

    @Override
    public void afterCellDispose(final WriteSheetHolder writeSheetHolder, final WriteTableHolder writeTableHolder,
                                 final List<CellData> list, final Cell cell, final Head head, final Integer integer,
                                 final Boolean aBoolean) {

    }
}

在这里我们对afterCellDispose动点手脚，在after之后操作。

@Override
    public void afterCellDispose(final WriteSheetHolder writeSheetHolder, final WriteTableHolder writeTableHolder,
                                 final List<CellData> list, final Cell cell, final Head head, final Integer integer,
                                 final Boolean aBoolean) {
        Sheet sheet = writeSheetHolder.getSheet();
        Workbook workbook = sheet.getWorkbook();
        // xlsx格式，如果是老版本格式的话就用 HSSFRichTextString
        XSSFRichTextString richString = new XSSFRichTextString(cell.getStringCellValue());
        Font font = workbook.createFont();
        font.setColor(Font.COLOR_RED);
        // 从哪到哪，你想设置成什么样的字体都行startIndex，endIndex
        richString.applyFont(0, 2, font);
        // 再设置回每个单元格里
        cell.setCellValue(richString);
    }

配置咱们就写完了，最后最最最重要的就是，富文本得把inMemory设置为true，不然没有效果噢，俺白忙活了一天，太可恶了惹。

EasyExcel.write(response.getOutputStream(), ReportVO.class)
            .inMemory(true) // 富文本
            .registerWriteHandler(new WriteHandlerStrategy()).build();

正常调用写excel的时候增加inMemory(true)和注册拦截registerWriteHandler(new WriteHandlerStrategy())，把咱们自定义的类放进去。

白忙了一天，早知道用poi了，这个地方可是大坑inMemory(true)!!!