Java实现PDF添加图片水印和文字水印

分手后的思念是犯贱 2023-10-18 13:27 16阅读 0赞

这篇文章介绍如何在Java应用程序中实现给PDF文档添加图片水印和文字水印。

本方案使用了免费PDF组件[Free Spire.PDF for Java][]，以下代码需要添加的jar包：

*  Spire.Pdf.jar

(下载Free Spire.PDF for Java类库，解压缩后在lib文件夹下可找到这个jar文件)

**PDFWatermark.java代码**

import com.spire.pdf.PdfDocument;
    import com.spire.pdf.PdfPageBase;
    import com.spire.pdf.graphics.*;
    
    import java.awt.*;
    import java.awt.geom.Dimension2D;
    import java.awt.geom.Point2D;
    import java.awt.geom.Rectangle2D;
    
    public class PDFWatermark {
        public static void main(String[] args)
        {
            //加载PDF文档
            PdfDocument pdf = new PdfDocument();
            pdf.loadFromFile("Additional.pdf");
    
            //调用AddImageWatermark方法给PDF第一页添加图片水印
            AddImageWatermark(pdf.getPages().get(0), "timg.jpg");
    
            //调用AddTextWatermark方法给PDF第二页添加文字水印
            AddTextWatermark(pdf.getPages().get(1), "已审阅");
    
            //保存
            pdf.saveToFile("Watermark.pdf");
            //关闭
            pdf.close();
        }
    
        /**
        * @param page
        * 要添加水印的页面
        * @param imageFile
        * 水印图片路径
         */
        static void AddImageWatermark(PdfPageBase page, String imageFile)
        {
            page.setBackgroundImage(imageFile);
            Rectangle2D rect = new Rectangle2D.Float();
            rect.setFrame(page.getClientSize().getWidth()/2 - 100, page.getClientSize().getHeight()/2 - 100, 200, 200);
            page.setBackgroundRegion(rect);
        }
    
        /**
         * @param page
         * 要添加水印的页面
         * @param textWatermark
         * 水印文字
         */
        static void AddTextWatermark(PdfPageBase page, String textWatermark)
        {
            Dimension2D dimension2D = new Dimension();
            dimension2D.setSize(page.getCanvas().getClientSize().getWidth() / 2, page.getCanvas().getClientSize().getHeight() / 3);
            PdfTilingBrush brush = new PdfTilingBrush(dimension2D);
            brush.getGraphics().setTransparency(0.3F);
            brush.getGraphics().save();
            brush.getGraphics().translateTransform((float) brush.getSize().getWidth() / 2, (float) brush.getSize().getHeight() / 2);
            brush.getGraphics().rotateTransform(-45);
            brush.getGraphics().drawString(textWatermark, new PdfTrueTypeFont(new Font("Arial Unicode MS",Font.PLAIN,30),true), PdfBrushes.getRed(), 0, 0, new PdfStringFormat(PdfTextAlignment.Center));
            brush.getGraphics().restore();
            brush.getGraphics().setTransparency(1);
            Rectangle2D loRect = new Rectangle2D.Float();
            loRect.setFrame(new Point2D.Float(0, 0), page.getCanvas().getClientSize());
            page.getCanvas().drawRectangle(brush, loRect);
        }
    }

添加图片水印效果：

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L0VpY2VibHVl_size_16_color_FFFFFF_t_70][]

添加文本水印效果：

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L0VpY2VibHVl_size_16_color_FFFFFF_t_70 1][]

[Free Spire.PDF for Java]: https://www.e-iceblue.cn/Downloads/Free-Spire-PDF-JAVA.html
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L0VpY2VibHVl_size_16_color_FFFFFF_t_70]: https://img-blog.csdnimg.cn/2019010515441415.png?x-oss-process=image/watermark,type_ZmFuZ3poZW5naGVpdGk,shadow_10,text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L0VpY2VibHVl,size_16,color_FFFFFF,t_70
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L0VpY2VibHVl_size_16_color_FFFFFF_t_70 1]: https://img-blog.csdnimg.cn/20190105154413953.png?x-oss-process=image/watermark,type_ZmFuZ3poZW5naGVpdGk,shadow_10,text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L0VpY2VibHVl,size_16,color_FFFFFF,t_70