想要 通過 自定義RGB 來設置 導出 excel 的表頭顏色

pom 依賴

 <dependency>
            <groupId>com.alibaba</groupId>
            <artifactId>easyexcel</artifactId>
            <version>2.2.7</version>
        </dependency>

相關示例代碼
ExcelUtils 工具類中可以本地測試

/**
 * 表頭 顏色 定義
 */
public class ComplexHeadStyles {
    /**
     * 表頭橫坐標 - 行
     */
    private Integer x;

    /**
     * 表頭縱坐標 - 列
     */
    private Integer y;

    /**
     * 內置顏色
     */
    private Short indexColor;

    private Integer red;
    private Integer green;
    private Integer blue;

    public ComplexHeadStyles(Integer x, Integer y, Short indexColor) {
        this.x = x;
        this.y = y;
        this.indexColor = indexColor;
    }
    public ComplexHeadStyles(Integer x, Integer y, Integer red, Integer green, Integer blue) {
        this.x = x;
        this.y = y;
        this.red = red;
        this.green = green;
        this.blue = blue;
    }
    public Integer getX() {
        return x;
    }

    public Integer getY() {
        return y;
    }

    public Short getIndexColor() {
        return indexColor;
    }
    public Integer getRed() {
        return red;
    }
    public Integer getGreen() {
        return green;
    }
    public Integer getBlue() {
        return blue;
    }
}

/**
 * 自定義表頭樣式攔截器
 *
 * @since 2022-07-21 14:26
 */
public class CustomHeadWriteHandler extends AbstractCellStyleStrategy {
    /**
     * 復雜表頭自定義樣式隊列，先進先出，方便存儲
     */
    private ArrayBlockingQueue<ComplexHeadStyles> headStylesQueue;

    public CustomHeadWriteHandler(ArrayBlockingQueue<ComplexHeadStyles> headStylesQueue) {
        this.headStylesQueue = headStylesQueue;
    }
    @Override
    public void afterCellCreate(WriteSheetHolder writeSheetHolder, WriteTableHolder writeTableHolder, Cell cell, Head head, Integer relativeRowIndex, Boolean isHead) {
        if (isHead) {
            if (headStylesQueue != null && !headStylesQueue.isEmpty()) {
                ComplexHeadStyles complexHeadStyle = headStylesQueue.peek();
                Sheet sheet = writeSheetHolder.getSheet();
                Workbook workbook = sheet.getWorkbook();
                CellStyle cellStyle = initCellStyleCustom(workbook);
                // 取出隊列中的自定義表頭信息，與當前坐標比較，判斷是否相符
                if (cell.getColumnIndex() == complexHeadStyle.getY() && relativeRowIndex.equals(complexHeadStyle.getX())) {
                    if (ObjectUtil.isNotEmpty(complexHeadStyle.getIndexColor())) {
                        //有指定顏色顏色 索引
                        cellStyle.setFillForegroundColor(complexHeadStyle.getIndexColor());
                        cellStyle.setFillPattern(FillPatternType.SOLID_FOREGROUND);
                        cell.setCellStyle(cellStyle);
                    } else {
                        //有指定顏色 RGB
                        if (ObjectUtil.isNotEmpty(complexHeadStyle.getRed()) && ObjectUtil.isNotEmpty(complexHeadStyle.getGreen()) && ObjectUtil.isNotEmpty(complexHeadStyle.getBlue())) {
                            XSSFCellStyle xssfCellStyle = (XSSFCellStyle)workbook.createCellStyle();
                            xssfCellStyle.cloneStyleFrom(cellStyle);
                            xssfCellStyle.setFillForegroundColor(new XSSFColor(new java.awt.Color(complexHeadStyle.getRed(), complexHeadStyle.getGreen(), complexHeadStyle.getBlue())));
                            xssfCellStyle.setFillPattern(FillPatternType.SOLID_FOREGROUND);
                            cell.setCellStyle(xssfCellStyle);
                        }
                    }
                    // 樣式出隊
                    headStylesQueue.poll();
                }
            }
        }
    }
    @Override
    protected void initCellStyle(Workbook workbook) {

    }
    @Override
    protected void setHeadCellStyle(Cell cell, Head head, Integer relativeRowIndex) {

    }
    @Override
    protected void setContentCellStyle(Cell cell, Head head, Integer relativeRowIndex) {

    }

    private CellStyle initCellStyleCustom(Workbook workbook) {
        CellStyle style = workbook.createCellStyle();
        style.setBorderBottom(BorderStyle.THIN);   // 下邊框
        style.setBorderLeft(BorderStyle.THIN);     // 左邊框
        style.setBorderTop(BorderStyle.THIN);      // 上邊框
        style.setBorderRight(BorderStyle.THIN);    // 右邊框

        Font font = workbook.createFont();
        font.setFontName("微軟雅黑"); // 字體樣式
        font.setBold(false);    // 是否加粗
        font.setFontHeightInPoints((short)13);   // 字體大小
        style.setFont(font);
        return style;
    }
}

/**
 * excel 工具類
 */
public class ExcelUtils {

    /**
     * excel 導出樣式 默認
     *
     * @return
     */
    public static WriteHandler setExcelStyle() {
        // 頭的策略
        WriteCellStyle headWriteCellStyle = new WriteCellStyle();
        // 背景設置為橙色
        headWriteCellStyle.setFillForegroundColor(IndexedColors.ORANGE.getIndex());
        WriteFont headWriteFont = new WriteFont();
        headWriteFont.setColor(IndexedColors.WHITE.getIndex());
        headWriteFont.setFontName("微軟雅黑");
        headWriteFont.setFontHeightInPoints((short)13);
        headWriteCellStyle.setWriteFont(headWriteFont);
        // 內容的策略
        WriteCellStyle contentWriteCellStyle = new WriteCellStyle();
        WriteFont contentWriteFont = new WriteFont();
        contentWriteFont.setFontName("微軟雅黑");
        contentWriteFont.setFontHeightInPoints((short)11);
        contentWriteFont.setColor(IndexedColors.BLACK.getIndex());
        // 字體大小
        contentWriteCellStyle.setWriteFont(contentWriteFont);
        // 這個策略是 頭是頭的樣式 內容是內容的樣式 其他的策略可以自己實現
        return new HorizontalCellStyleStrategy(headWriteCellStyle, contentWriteCellStyle);
    }

    /**
     * 導出文件時為Writer生成OutputStream
     *
     * @param fileName 文件名
     * @param response response
     * @return 流
     */
    public static OutputStream getOutputStream(String fileName, HttpServletResponse response) throws Exception {
        try {
            fileName = URLEncoder.encode(fileName, "utf-8");
            response.setCharacterEncoding("utf8");
            response.setContentType("multipart/form-data");
            response.setHeader("Content-Disposition", "attachment;filename*=utf-8'zh_cn'" + fileName + ".xlsx");
            return response.getOutputStream();
        } catch (IOException e) {
            throw new Exception("導出excel表格失敗!", e);
        }
    }

    /**
     * excel 導出樣式 測試
     *
     * @return
     */
    public static WriteHandler setTestTemplateSheet0() {
        // 設置表頭樣式隊列【先進先出】
        ArrayBlockingQueue<ComplexHeadStyles> complexHeadStylesArrayBlockingQueue = new ArrayBlockingQueue<>(3);

        /**
         * 顏色
         */
        complexHeadStylesArrayBlockingQueue.add(new ComplexHeadStyles(0, 0, 102, 255, 255));
        complexHeadStylesArrayBlockingQueue.add(new ComplexHeadStyles(0, 1, IndexedColors.ORANGE.getIndex()));
        complexHeadStylesArrayBlockingQueue.add(new ComplexHeadStyles(0, 2, IndexedColors.GREY_25_PERCENT.getIndex()));
        CustomHeadWriteHandler headStyleWriteHandler = new CustomHeadWriteHandler(complexHeadStylesArrayBlockingQueue);
        return headStyleWriteHandler;
    }

    public static List<List<String>> getTestHeader0(List<List<Object>> list0) {
        List<List<String>> list = Lists.newArrayList();
        List<String> head0 = Lists.newArrayList("第一列");
        List<String> head1 = Lists.newArrayList("第二列");
        List<String> head2 = Lists.newArrayList("第三列");
        list.add(head0);
        list.add(head1);
        list.add(head2);
        List<Object> row1 = Lists.newArrayList("111", "222", "333");
        list0.add(row1);
        return list;
    }

    public static ByteArrayOutputStream getExcelTestOut(HttpServletResponse response) {
        ExcelWriter excelWriter = null;
        ByteArrayOutputStream out = new ByteArrayOutputStream();
        try {
            if (ObjectUtil.isNotEmpty(response)) {
                excelWriter = EasyExcel.write(getOutputStream("test", response)).registerWriteHandler(setExcelStyle()).build();
            } else {
                excelWriter = EasyExcel.write(out).registerWriteHandler(setExcelStyle()).build();
            }

            List<List<Object>> list0 = Lists.newArrayList();
            List<List<String>> header0 = getTestHeader0(list0);
            //獲取sheet對象
            WriteSheet sheet0 = EasyExcel.writerSheet(0, "test").head(header0).registerWriteHandler(ExcelUtils.setTestTemplateSheet0()).build();
            excelWriter.write(list0, sheet0);
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            excelWriter.finish();
        }
        return out;
    }

    public static void main(String[] args) throws IOException {
        ByteArrayOutputStream excelTestOut = getExcelTestOut(null);
        //建立文件
        File file = new File("D:\\test.xlsx");
        if (file.exists()) {
            System.out.println("文件已存在");
            return;
        }
        file.createNewFile();
        FileOutputStream fileOutputStream = new FileOutputStream(file.getPath());
        fileOutputStream.write(excelTestOut.toByteArray());
        fileOutputStream.close();
    }
}