POI Excel插入水印（只支持07版Excel文档）

本是古典何须时尚 2023-09-29 11:37 21阅读 0赞

**目录**

1 Maven依赖

2 实现代码

2.1 createWaterMark

2.2 insertWaterRemark

3 调试代码

4 调试结果

注：

--------------------

## 1 Maven依赖 ##

<dependency>
                <groupId>com.alibaba</groupId>
                <artifactId>easyexcel</artifactId>
                <version>2.2.8</version>
            </dependency>
            
            <dependency>
                <groupId>cn.afterturn</groupId>
                <artifactId>easypoi-base</artifactId>
                <version>4.4.0</version>
            </dependency>
            <dependency>
                <groupId>org.apache.poi</groupId>
                <artifactId>ooxml-schemas</artifactId>
                <version>1.4</version>
            </dependency>

## 2 实现代码 ##

### 2.1 createWaterMark ###

生成水印数据。

/**
         * 生成水印
         *
         * @param content 水印内容
         * @param width   宽度
         * @param height  高度
         * @param color   字体颜色
         * @param font    字体信息
         * @return
         * @throws IOException
         */
        public static byte[] createWaterMark(String content, int width, int height, java.awt.Color color, java.awt.Font font) throws IOException {
            // 获取bufferedImage对象
            BufferedImage image = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB);
            // 获取Graphics2d对象
            Graphics2D g2d = image.createGraphics();
            image = g2d.getDeviceConfiguration().createCompatibleImage(width, height, Transparency.TRANSLUCENT);
            g2d.dispose();
            g2d = image.createGraphics();
            //设置字体颜色
            g2d.setColor(color);
            g2d.setStroke(new BasicStroke(1));
            // 设置字体
            g2d.setFont(font);
            //设置倾斜度
            g2d.rotate(-0.5, (double) image.getWidth() / 2, (double) image.getHeight() / 2);
            FontRenderContext context = g2d.getFontRenderContext();
            Rectangle2D bounds = font.getStringBounds(content, context);
            double x = (width - bounds.getWidth()) / 2;
            double y = (height - bounds.getHeight()) / 2;
            double ascent = -bounds.getY();
            double baseY = y + ascent;
            // 写入水印文字原定高度过小，所以累计写水印，增加高度
            g2d.drawString(content, (int) x, (int) baseY);
            // 设置透明度
            g2d.setComposite(AlphaComposite.getInstance(AlphaComposite.SRC_OVER));
            // 释放对象
            g2d.dispose();
            ByteArrayOutputStream os = new ByteArrayOutputStream();
            ImageIO.write(image, "png", os);
            return os.toByteArray();
        }

### 2.2 insertWaterRemark ###

插入水印，只支持07版Excel文档。

/**
         * 插入水印
         *
         * @param sheet sheet对象
         * @param bytes 水印图片字节数组
         */
        public static void insertWaterRemark(XSSFSheet sheet, byte[] bytes) {
            //水印图片数据关联sheet对象
            XSSFWorkbook workbook = sheet.getWorkbook();
            int pictureIdx = workbook.addPicture(bytes, Workbook.PICTURE_TYPE_PNG);
            String relationId = sheet.addRelation(null, XSSFRelation.IMAGES, workbook.getAllPictures().get(pictureIdx))
                    .getRelationship().getId();
            //将水印图片设置为sheet的背景颜色
            sheet.getCTWorksheet().addNewPicture().setId(relationId);
        }

## 3 调试代码 ##

/**
         * 测试插入水印
         */
        @Test
        public void testInsertWaterMark() {
            try {
                XSSFWorkbook workbook = new XSSFWorkbook();
                XSSFSheet sheet = workbook.createSheet();
                File file = new File("D:/poi/testInsertWaterMark.xlsx");
                FileUtil.createNewFile(file);
                //生成水印
                byte[] waterMarkBytes = createWaterMark("旭东怪YYDS", 200, 150, new Color(255, 0, 0, 100)
                        , new Font("微软雅黑", Font.BOLD, 20));
                //插入水印
                insertWaterRemark(sheet, waterMarkBytes);
                workbook.write(new FileOutputStream(file));
            } catch (Exception e) {
                e.printStackTrace();
            }
        }

## 4 调试结果 ##

![watermark_type_d3F5LXplbmhlaQ_shadow_50_text_Q1NETiBA5pet5Lic5oCq_size_20_color_FFFFFF_t_70_g_se_x_16][]

## 注： ##

觉得这篇博客写的不错的可以前往Gitee点个Star，源码请查看Gitee的xudongbase项目poi分支。

[xudongbase: 主要是项目中可以用到的共通方法，现有easyexcel分支在持续更新中。欢迎大家Star和提交Issues。easyexcel分支：批量设置样式，批量添加批注，批量合并单元格，设置冻结行和列，设置行高列宽，隐藏行和列，绑定下拉框数据 - Gitee.com][xudongbase_ _easyexcel_Star_Issues_easyexcel_ - Gitee.com]

[watermark_type_d3F5LXplbmhlaQ_shadow_50_text_Q1NETiBA5pet5Lic5oCq_size_20_color_FFFFFF_t_70_g_se_x_16]: https://img-blog.csdnimg.cn/31b1f512626a44a5b04ef843ccac8dad.png?x-oss-process=image/watermark,type_d3F5LXplbmhlaQ,shadow_50,text_Q1NETiBA5pet5Lic5oCq,size_20,color_FFFFFF,t_70,g_se,x_16
[xudongbase_ _easyexcel_Star_Issues_easyexcel_ - Gitee.com]: https://gitee.com/xudong_master/xudongbase/tree/poi/