Excel使用apache poi 添加水印图片

van@duduladudu

Excel使用apache poi 添加水印图片

工作中需要为excel添加水印图片，大概分为两种方式
1、使用java Graphics2D来创建图片，插入excel文件背景图中
2、使用已有的图片，插入到excel文件到背景图中国呢

代码如下

import java.io.*;
import java.awt.image.BufferedImage;
import javax.imageio.ImageIO;
import org.apache.poi.POIXMLDocumentPart;
import org.apache.poi.openxml4j.opc.PackagePartName;
import org.apache.poi.openxml4j.opc.PackageRelationship;
import org.apache.poi.openxml4j.opc.TargetMode;
import org.apache.poi.ss.usermodel.*;
import org.apache.poi.xssf.usermodel.XSSFRelation;
import org.apache.poi.xssf.usermodel.XSSFSheet;
import org.apache.poi.xssf.usermodel.XSSFWorkbook;

public class TestAddWaterStamp {

    public static void main(String[] args) {
        String sourceImagePath = "/Users/xxx/Desktop/2.png";

        try {
            //创建一个图片流，水印图片可以用现有图片，也可以用java Graphics2D来创建
            //使用java创建水印图片
            FontImage.Watermark watermark = new FontImage.Watermark("xxx资产","yyyy-MM-dd HH:mm","#C5CBCF",true);
            BufferedImage image = FontImage.createWatermarkImage(watermark);
            //使用已有的图片
            BufferedImage image2 = ImageIO.read(new File(sourceImagePath));
            // 导出到字节流B
            ByteArrayOutputStream os = new ByteArrayOutputStream();
            ByteArrayOutputStream os2 = new ByteArrayOutputStream();
            ImageIO.write(image, "png", os);
            ImageIO.write(image2, "png", os2);

            // 创建工作簿对象
            XSSFWorkbook workbook = new XSSFWorkbook(); // 或者使用 HSSFWorkbook for .xls 格式
            FileOutputStream out = new FileOutputStream("/Users/xxx/Desktop/testexcel.xlsx");


            String relType = XSSFRelation.IMAGES.getRelation();

            //使用java绘制图片的excel展示
            XSSFSheet sheet = workbook.createSheet("sheet1");
            //创建图片和excel表格的数据关联
            int pictureIdx = workbook.addPicture(os.toByteArray(), Workbook.PICTURE_TYPE_PNG);
            POIXMLDocumentPart poixmlDocumentPart =  workbook.getAllPictures().get(pictureIdx);
            PackagePartName ppn = poixmlDocumentPart.getPackagePart().getPartName();
            PackageRelationship pr = sheet.getPackagePart().addRelationship(ppn, TargetMode.INTERNAL, relType, null);
            //设置背景图片
            sheet.getCTWorksheet().addNewPicture().setId(pr.getId());

            //使用已有图片的excel展示
            XSSFSheet sheet2 = workbook.createSheet("sheet2");
            int pictureIdx2 = workbook.addPicture(os2.toByteArray(), Workbook.PICTURE_TYPE_PNG);
            POIXMLDocumentPart poixmlDocumentPart2 =  workbook.getAllPictures().get(pictureIdx2);
            PackagePartName ppn2 = poixmlDocumentPart2.getPackagePart().getPartName();

            PackageRelationship pr2 = sheet2.getPackagePart().addRelationship(ppn2, TargetMode.INTERNAL, relType, null);
            sheet2.getCTWorksheet().addNewPicture().setId(pr2.getId());

            //TODO 为所有sheet添加水印图片，可以使用循环调用的方式处理

            // 保存Excel文件
            FileOutputStream fileOut = new FileOutputStream("/Users/xxx/Desktop/testexcel2.xlsx");
            workbook.write(fileOut);
            fileOut.close();

        } catch (IOException e) {
            e.printStackTrace();
        }

    }
}

import lombok.Data;
import org.springframework.util.StringUtils;
import java.awt.*;
import java.awt.image.BufferedImage;
public class FontImage {

    @Data
    public static class Watermark {
        private Boolean enable;
        private String text;
        private String dateFormat;
        private String color;
        public Watermark(String text,String dateFormat,String color,Boolean enable){
            this.text = text;
            this.dateFormat = dateFormat;
            this.color = color;
            this.enable = enable;
        }
    }

    public static BufferedImage createWatermarkImage(Watermark watermark) {
        if (watermark == null) {
            watermark = new FontImage.Watermark("内部资料","yyyy-MM-dd HH:mm","#C5CBCF",true);

        } else {
            if (StringUtils.isEmpty(watermark.getDateFormat())) {
                watermark.setDateFormat("yyyy-MM-dd HH:mm");
            } else if (watermark.getDateFormat().length() == 16) {
                watermark.setDateFormat("yyyy-MM-dd HH:mm");
            } else if (watermark.getDateFormat().length() == 10) {
                watermark.setDateFormat("yyyy-MM-dd");
            }
            if (StringUtils.isEmpty(watermark.getText())) {
                watermark.setText("内部资料");
            }
            if (StringUtils.isEmpty(watermark.getColor())) {
                watermark.setColor("#C5CBCF");
            }
        }
        String[] textArray = watermark.getText().split("\n");
        Font font = new Font("Serif", Font.ITALIC, 20);
        Integer width = 300;
        Integer height = 100;

        BufferedImage image = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB);
        // 背景透明 开始
        Graphics2D g = image.createGraphics();
        image = g.getDeviceConfiguration().createCompatibleImage(width, height, Transparency.TRANSLUCENT);
        g.dispose();
        // 背景透明 结束
        g = image.createGraphics();
        g.setColor(new Color(Integer.parseInt(watermark.getColor().substring(1), 16)));// 设定画笔颜色
        g.setFont(font);// 设置画笔字体
        g.shear(0.1, -0.26);// 设定倾斜度

//        设置字体平滑
        g.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);

        int y = 50;
        for (int i = 0; i < textArray.length; i++) {
            g.drawString(textArray[i], 0, y);// 画出字符串
            y = y + font.getSize();
        }
        g.drawString("2333333", 0, y);// 画出字符串

        g.dispose();// 释放画笔
        return image;

    }
}

pom依赖

		<dependency>
			<groupId>cn.afterturn</groupId>
			<artifactId>easypoi-spring-boot-starter</artifactId>
			<version>4.3.0</version>
		</dependency>

		<dependency>
			<groupId>org.apache.poi</groupId>
			<artifactId>poi-ooxml</artifactId>
			<version>3.9</version>
		</dependency>

		<dependency>
			<groupId>org.apache.poi</groupId>
			<artifactId>ooxml-schemas</artifactId>
			<version>1.0</version>
		</dependency>

本文参考以下文章：
1、java POI为excel添加水印
2、apache poi 官方文档
其中有问chatgpt但给到的答案无法满足水印的需求。