excel 添加水印 平铺

package com.watermarket; import cn.hutool.core.img.ImgUtil; import com.alibaba.excel.write.handler.SheetWriteHandler; import com.alibaba.excel.write.metadata.holder.WriteSheetHolder; import com.alibaba.excel.write.metadata.holder.WriteWorkbookHolder; 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.Workbook; import org.apache.poi.xssf.usermodel.XSSFPictureData; import org.apache.poi.xssf.usermodel.XSSFRelation; import org.apache.poi.xssf.usermodel.XSSFSheet; import org.apache.poi.xssf.usermodel.XSSFWorkbook; import java.awt.*; import java.awt.image.BufferedImage; public class CustomWaterMarkHandler implements SheetWriteHandler { private final WaterMark watermark; public CustomWaterMarkHandler(WaterMark watermark) { this.watermark = watermark; } @Override public void beforeSheetCreate(WriteWorkbookHolder writeWorkbookHolder, WriteSheetHolder writeSheetHolder) { } @Override public void afterSheetCreate(WriteWorkbookHolder writeWorkbookHolder, WriteSheetHolder writeSheetHolder) { try { BufferedImage bufferedImage = createWatermarkImage(); setWaterMarkToExcel((XSSFWorkbook) writeWorkbookHolder.getWorkbook(), bufferedImage); } catch (Exception e) { throw new RuntimeException("添加水印出错"); } } private BufferedImage createWatermarkImage() { final Font font = watermark.getFont(); final int width = watermark.getWidth(); final int height = watermark.getHeight(); String[] textArray = watermark.getContent().split(","); 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(); // 设定画笔颜色 g.setColor(new Color(Integer.parseInt(watermark.getColor().substring(1), 16))); // 设置画笔字体 g.setFont(font); // 设定倾斜度 g.shear(watermark.getShearX(), watermark.getShearY()); // 设置字体平滑 g.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON); int y = watermark.getYAxis(); for (String s : textArray) { // 从画框的y轴开始画字符串.假设电脑屏幕中心为0，y轴为正数则在下方 g.drawString(s, 0, y); y = y + font.getSize(); } // 释放画笔 g.dispose(); return image; } private void setWaterMarkToExcel(XSSFWorkbook workbook, BufferedImage bfi) { //将图片添加到工作簿 int pictureIdx = workbook.addPicture(ImgUtil.toBytes(bfi, ImgUtil.IMAGE_TYPE_PNG), Workbook.PICTURE_TYPE_PNG); //建立 sheet 和 图片 的关联关系 XSSFPictureData xssfPictureData = workbook.getAllPictures().get(pictureIdx); for (int i = 0; i < workbook.getNumberOfSheets(); i++) { XSSFSheet xssfSheet = workbook.getSheetAt(i); PackagePartName packagePartName = xssfPictureData.getPackagePart().getPartName(); PackageRelationship packageRelationship = xssfSheet.getPackagePart() .addRelationship(packagePartName, TargetMode.INTERNAL, XSSFRelation.IMAGES.getRelation(), null); //添加水印到工作表 xssfSheet.getCTWorksheet().addNewPicture().setId(packageRelationship.getId()); } } }