poi导出自定义文字水印excel文件_sheet.getctworksheet().addnewpicture()没有setid的方法-优快云博客

本文档展示了如何使用Apache POI库在XSSFWorkbook的工作表中添加全页透明水印，通过自定义文本并调整样式实现，同时提及了部分保护表格操作。

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直接上代码

注意Workbook和sheet都是XSSF开头的这种，水印效果是整个sheet页铺满自定义文本水印

import javax.imageio.ImageIO;
import java.awt.*;
import java.awt.font.FontRenderContext;
import java.awt.geom.Rectangle2D;
import java.awt.image.BufferedImage;
import java.io.ByteArrayOutputStream;
import java.io.IOException;

/**
 * @author lzl
 * @date 2022/10/13
 * @desc:
 */
public class ExcelUtil {
    /**
     * add watermark to each sheet of workbook
     *
     * @param wb
     * @throws IOException
     */
    public static void addWaterMark(XSSFWorkbook wb) throws IOException {
        ByteArrayOutputStream byteArrayOutputStream = ExcelUtil.createWaterMark("小烧杯");

        int pictureIdx = wb.addPicture(byteArrayOutputStream.toByteArray(), Workbook.PICTURE_TYPE_PNG);
        POIXMLDocumentPart poixmlDocumentPart = wb.getAllPictures().get(pictureIdx);
        for (int i = 0; i < wb.getNumberOfSheets(); i++) {
            XSSFSheet xssfSheet = wb.getSheetAt(i);
            PackagePartName ppn = poixmlDocumentPart.getPackagePart().getPartName();
            String relType = XSSFRelation.IMAGES.getRelation();
            PackageRelationship pr = xssfSheet.getPackagePart().addRelationship(ppn, TargetMode.INTERNAL, relType, null);
            xssfSheet.getCTWorksheet().addNewPicture().setId(pr.getId());
            // 下面三行代码可设置表格内容不可复制、编辑
//            xssfSheet.protectSheet(UUID.randomUUID().toString());
//            xssfSheet.lockSelectUnlockedCells();
//            xssfSheet.lockSelectLockedCells();
        }
    }

    public static ByteArrayOutputStream createWaterMark(String content)
            throws IOException {
        int width = 200;
        int height = 150;
        BufferedImage image = new BufferedImage(width, height,
                BufferedImage.TYPE_INT_RGB);// 获取bufferedImage对象
        String fontType = "微软雅黑";
        int fontStyle = Font.BOLD;
        int fontSize = 20;
        Font font = new Font(fontType, fontStyle, fontSize);
        Graphics2D g2d = image.createGraphics(); // 获取Graphics2d对象
        image = g2d.getDeviceConfiguration().createCompatibleImage(width,
                height, Transparency.TRANSLUCENT);
        g2d.dispose();
        g2d = image.createGraphics();
        g2d.setColor(new Color(0, 0, 0, 20)); // 设置字体颜色和透明度，最后一个参数为透明度
        g2d.setStroke(new BasicStroke(1)); // 设置字体
        g2d.setFont(font); // 设置字体类型 加粗 大小
        g2d.rotate(-0.5, (double) image.getWidth() / 2,
                (double) image.getHeight() / 2);// 设置倾斜度
        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;
    }

}