PDF动态图章通常由动态文字（如日期、时间）、经办人/组织名称、“已审核”等字样组成。本教程展示如何使用Spire.PDF for Java在PDF中添加动态图章。

import com.spire.pdf.annotations.PdfRubberStampAnnotation;
import com.spire.pdf.annotations.appearance.PdfAppearance;
import com.spire.pdf.graphics.*;

import java.awt.*;
import java.awt.geom.Point2D;
import java.awt.geom.Rectangle2D;
import java.text.SimpleDateFormat;

public class DynamicStamp {

    public static void main(String[] args) {

        //创建PdfDocument对象
        PdfDocument document = new PdfDocument();

        //加载PDF文档
        document.loadFromFile("C:\\Users\\Administrator\\Desktop\\test.pdf");

        //获取第一页
        PdfPageBase page = document.getPages().get(0);

        //创建PdfTamplate对象
        PdfTemplate template = new PdfTemplate(185, 50);

        //创建两种字体
        PdfTrueTypeFont font1 = new PdfTrueTypeFont(new Font("宋体", Font.PLAIN  ,15), true);
        PdfTrueTypeFont font2 = new PdfTrueTypeFont(new Font("宋体", Font.PLAIN  ,10), true);

        //创建单色画刷和渐变画刷
        PdfSolidBrush solidBrush = new PdfSolidBrush(new PdfRGBColor(Color.blue));
        Rectangle2D rect1 = new Rectangle2D.Float();
        rect1.setFrame(new Point2D.Float(0,0),template.getSize());
        PdfLinearGradientBrush linearGradientBrush = new PdfLinearGradientBrush(rect1,new PdfRGBColor(Color.white),new PdfRGBColor(Color.orange),PdfLinearGradientMode.Horizontal);

        //创建圆角矩形路径
        int CornerRadius = 20;
        PdfPath path = new PdfPath();
        path.addArc(template.getBounds().getX(), template.getBounds().getY(), CornerRadius, CornerRadius, 180, 90);
        path.addArc(template.getBounds().getX() + template.getWidth() - CornerRadius,template.getBounds().getY(), CornerRadius, CornerRadius, 270, 90);
        path.addArc(template.getBounds().getX() + template.getWidth() - CornerRadius, template.getBounds().getY()+ template.getHeight() - CornerRadius, CornerRadius, CornerRadius, 0, 90);
        path.addArc(template.getBounds().getX(), template.getBounds().getY() + template.getHeight() - CornerRadius, CornerRadius, CornerRadius, 90, 90);
        path.addLine( template.getBounds().getX(), template.getBounds().getY() + template.getHeight() - CornerRadius, template.getBounds().getX(), template.getBounds().getY() + CornerRadius / 2);

        //绘制路径到模板，并进行填充
        template.getGraphics().drawPath(linearGradientBrush, path);
        template.getGraphics().drawPath(PdfPens.getBlue(), path);

        //在模板上绘制文字及动态日期
        String s1 = "已审核\n";
        String s2 = "销售部 " + dateToString(new java.util.Date(),"yyyy-MM-dd HH:mm:ss");
        template.getGraphics().drawString(s1, font1, solidBrush, new Point2D.Float(5, 5));
        template.getGraphics().drawString(s2, font2, solidBrush, new Point2D.Float(5, 28));

        //创建PdfRubberStampAnnotation对象，并指定其位置和大小
        Rectangle2D rect2= new Rectangle2D.Float();
        rect2.setFrame(new Point2D.Float((float)(page.getActualSize().getWidth()-250),(float)(page.getActualSize().getHeight()-120)),  template.getSize());
        PdfRubberStampAnnotation stamp = new PdfRubberStampAnnotation(rect2);

        //创建PdfAppearance对象，应用模板为一般状态
        PdfAppearance appearance = new PdfAppearance(stamp);
        appearance.setNormal(template);

        //应用样式到图章
        stamp.setAppearance(appearance);

        //添加图章到Annotation集合
        page.getAnnotationsWidget().add(stamp);

        //保存文档
        document.saveToFile("DynamicStamp.pdf");
        document.close();
    }

    //将日期转化成字符串
    public static String dateToString(java.util.Date poDate,String pcFormat) {
        SimpleDateFormat loFormat = new SimpleDateFormat(pcFormat);
        return loFormat.format(poDate);
    }
}