EasyExcel 自定义样式

需求：导出数据的内容行，按照每三行设置背景色为 灰色、。
easyexcel 版本

        <dependency>
            <groupId>com.alibaba</groupId>
            <artifactId>easyexcel</artifactId>
            <version>2.2.6</version>
        </dependency>

1、导出的实体类

@Data
@Builder
public class ExportExcel {
    
    
    @ExcelProperty("姓名")
    private String name;

    @ExcelProperty("年龄")
    private Integer age;
}

2、controller 接口

    @GetMapping("export")
    public void export(HttpServletResponse response) {
    
    
        log.info("导出数据开始");
        try {
    
    
        	// 构建数据
            List<ExportExcel> list = new ArrayList<>();
            for (int i = 1; i < 500; i++) {
    
    
                list.add(ExportExcel.builder().name("TIMI"+i+"").age(i).build());
            }

			// 导出设置
            response.setCharacterEncoding("UTF-8");
            response.setHeader("content-Type", "application/vnd.ms-excel");
            String fileName = URLEncoder.encode("测试数据表", "UTF-8").replaceAll("\\+", "%20");
            response.setHeader("Content-Disposition", "attachment;filename=" + fileName + ".xls");

            EasyExcel.write(response.getOutputStream(), ExportExcel.class).autoCloseStream(Boolean.FALSE)
                    .registerWriteHandler(new CustomCellWriteHandler())
                    .sheet("测试数据表")
                    .doWrite(list);
            log.info("导出数据结束");
        }catch (Exception e){
    
    
            throw new RuntimeException("导出数据失败:" + e.getMessage());
        }
    }

3、自定义样式

public class CustomCellWriteHandler extends AbstractCellWriteHandler {
    
    

    /**
     * 用于存储单元格样式对象
     * 将 CellStyle 缓存下来，防止导出：超过创建超过6W个CellStyle对象报错
     */
    private Map<String, CellStyle> contentCellStyleCache = new HashMap<String, CellStyle>();

    /**
     * 缓存的 单元格样式对象  的KEY
     */
    public final static String CELL_STYLE_CACHE_KEY = "CELL_STYLE_CACHE_KEY";

    /**
     * 每 ROW_PARAM 行设置背景色
     */
    public final static int ROW_PARAM = 3;


    @Override
    public void afterCellDispose(WriteSheetHolder writeSheetHolder, WriteTableHolder writeTableHolder,
                                 List<CellData> cellDataList, Cell cell, Head head, Integer relativeRowIndex, Boolean isHead) {
    
    
        if (!isHead) {
    
    
            // 除头外，每三行设置背景色
            if ((relativeRowIndex + 1) % ROW_PARAM == 0) {
    
    
                CellStyle cellStyle = contentCellStyleCache.get(CELL_STYLE_CACHE_KEY);
                if (ObjectUtil.isNull(cellStyle)) {
    
    
                    Workbook workbook = writeSheetHolder.getParentWriteWorkbookHolder().getWorkbook();
                    cellStyle = workbook.createCellStyle();
                    contentCellStyleCache.put(CELL_STYLE_CACHE_KEY, cellStyle);
                }
                cellStyle.setFillForegroundColor(IndexedColors.GREY_25_PERCENT.getIndex());
                cellStyle.setFillPattern(FillPatternType.SOLID_FOREGROUND);
                cell.setCellStyle(cellStyle);
            }
        }
    }
}

以上的方式即可实现自定义背景色导出。

ps：之前使用的其他方式，导致导出时报错：The maximum number of cell styles was exceeded ，使用以上方式，完美的解决。