Java在Excel中添加水印的实现(单一水印、平铺水印)

import com.spire.xls.*;

import java.awt.*;
import java.awt.image.BufferedImage;

import static java.awt.image.BufferedImage.TYPE_INT_ARGB;

public class SingleWatermark {
    public static void main(String[] args) {
        //加载Excel测试文档
        Workbook wb = new Workbook();
        wb.loadFromFile("test.xlsx");

        //设置文本和字体大小
        Font font = new Font("仿宋", Font.PLAIN, 40);

        for (int i =0;i<wb.getWorksheets().getCount();i++)
        {
            Worksheet sheet = wb.getWorksheets().get(i);
            //调用DrawText() 方法插入图片
            BufferedImage imgWtrmrk = drawText("内部专用", font, Color.pink, Color.white, sheet.getPageSetup().getPageHeight(), sheet.getPageSetup().getPageWidth());

            //将图片设置为页眉
            sheet.getPageSetup().setCenterHeaderImage(imgWtrmrk);
            sheet.getPageSetup().setCenterHeader("&G");


            //将显示模式设置为Layout
            sheet.setViewMode(ViewMode.Layout);
        }

        //保存文档
        wb.saveToFile("SingleWatermark.xlsx", ExcelVersion.Version2013);
    }
    private static BufferedImage drawText (String text, Font font, Color textColor, Color backColor,double height, double width)
    {
        //定义图片宽度和高度
        BufferedImage img = new BufferedImage((int) width, (int) height, TYPE_INT_ARGB);

        Graphics2D loGraphic = img.createGraphics();

        //获取文本size
        FontMetrics loFontMetrics = loGraphic.getFontMetrics(font);
        int liStrWidth = loFontMetrics.stringWidth(text);
        int liStrHeight = loFontMetrics.getHeight();

        //文本显示样式及位置
        loGraphic.setColor(backColor);
        loGraphic.fillRect(0, 0, (int) width, (int) height);
        loGraphic.translate(((int) width - liStrWidth) / 2, ((int) height - liStrHeight) / 2);
        loGraphic.rotate(Math.toRadians(-45));

        loGraphic.translate(-((int) width - liStrWidth) / 2, -((int) height - liStrHeight) / 2);
        loGraphic.setFont(font);
        loGraphic.setColor(textColor);
        loGraphic.drawString(text, ((int) width - liStrWidth) / 2, ((int) height - liStrHeight) / 2);
        loGraphic.dispose();
        return img;
    }
}

import com.spire.xls.*;

import java.awt.*;
import java.awt.image.BufferedImage;

import static java.awt.image.BufferedImage.TYPE_INT_ARGB;

public class TiledWatermark {
    public static void main(String[] args) {
        //加载Excel测试文档
        Workbook wb = new Workbook();
        wb.loadFromFile("test.xlsx");

        //设置文本和字体大小
        Font font = new Font("仿宋", Font.PLAIN, 25);

        for (int i =0;i<wb.getWorksheets().getCount();i++)
        {
            Worksheet sheet = wb.getWorksheets().get(i);
            //调用DrawText() 方法插入图片
            BufferedImage imgWtrmrk = drawText("内部专用     内部专用     内部专用     内部专用", font, Color.pink, Color.white, sheet.getPageSetup().getPageHeight(), sheet.getPageSetup().getPageWidth());

            //将图片设置为页眉
            sheet.getPageSetup().setCenterHeaderImage(imgWtrmrk);
            sheet.getPageSetup().setCenterHeader("&G");

            //将显示模式设置为Layout
            sheet.setViewMode(ViewMode.Layout);
        }

        //保存文档
        wb.saveToFile("TiledWatermark.xlsx", ExcelVersion.Version2013);
    }
    private static BufferedImage drawText (String text, Font font, Color textColor, Color backColor,double height, double width)
    {
        //定义图片宽度和高度
        BufferedImage img = new BufferedImage((int) width, (int) height, TYPE_INT_ARGB);

        Graphics2D loGraphic = img.createGraphics();

        //获取文本size
        FontMetrics loFontMetrics = loGraphic.getFontMetrics(font);
        int liStrWidth = loFontMetrics.stringWidth(text);
        int liStrHeight = loFontMetrics.getHeight();

        //文本显示样式及位置
        loGraphic.setColor(backColor);
        loGraphic.fillRect(0, 0, (int) width, (int) height);
        loGraphic.translate(((int) width - liStrWidth) / 2, ((int) height - liStrHeight) / 2);
        //loGraphic.rotate(Math.toRadians(-45));

        loGraphic.translate(-((int) width - liStrWidth) / 2, -((int) height - liStrHeight) / 2);
        loGraphic.setFont(font);
        loGraphic.setColor(textColor);
        loGraphic.drawString(text, ((int) width - liStrWidth) /6 , ((int) height - liStrHeight) /6);
        loGraphic.drawString(text,((int) width - liStrWidth) /3, ((int) height - liStrHeight) /3);
        loGraphic.drawString(text,((int) width - liStrWidth) /2, ((int) height - liStrHeight) /2);
        loGraphic.dispose();
        return img;
    }
}