Java 在PDF中添加骑缝章

朱雀 2020-10-30 16:46 794阅读 0赞

骑缝章是用于往来业务合同，以确保合同真实、有效的印章加盖方法，是一种防范风险的重要方式。在Java程序中，可以通过使用工具来辅助加盖这种骑缝章。

**工具：Free Spire.PDF for Java （免费版）**

**工具获取及jar文件导入：**

**方式1：**通过官网[下载jar包][jar]，并解压，手动导入lib文件夹下的Spire.Pdf.jar文件。

**方式2：**通过创建Maven程序，在pom.xml中配置maven仓库路径并指定Free Spire.PDF for Java 的依赖，配置完成后，在IDEA中，点击“Import Changes”导入JAR包：

<repositories>
            <repository>
                <id>com.e-iceblue</id>
                  <url>http://repo.e-iceblue.cn/repository/maven-public/</url>
            </repository>
    </repositories>
    
    <dependencies>
        <dependency>
            <groupId>e-iceblue</groupId>
            <artifactId>spire.pdf.free</artifactId>
            <version>2.6.3</version>
        </dependency>
    </dependencies>

*（Ecllipse**的导入方法，参考这篇*[文章][Link 1]*）*

jar导入结果如下图所示：

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L0VpY2VibHVl_size_16_color_FFFFFF_t_70][]

**Java示例**

import java.io.IOException;
    import com.spire.pdf.*;
    import com.spire.pdf.graphics.*;
    import javax.imageio.ImageIO;
    import java.awt.*;
    import java.awt.geom.Point2D;
    import java.awt.image.BufferedImage;
    import java.io.*;
    
    public class AddSeal {
        public static void main(String[] args) throws IOException {
            //加载测试文档
            PdfDocument doc = new PdfDocument();
            doc.loadFromFile("C:\\Users\\Test1\\Desktop\\Demo.pdf");
    
            PdfUnitConvertor convert = new PdfUnitConvertor();
            PdfPageBase pageBase = null;
    
            //获取分割后的印章图片
            BufferedImage[] images = GetImage(doc.getPages().getCount());
            float x = 0;
            float y = 0;
    
            //将图片绘制到PDF页面上的指定位置
            for (int i = 0; i < doc.getPages().getCount(); i++)
            {
                BufferedImage image= images[ i ];
                pageBase = doc.getPages().get(i);
                x = (float)(pageBase.getSize().getWidth()) - convert.convertUnits(image.getWidth(), PdfGraphicsUnit.Pixel, PdfGraphicsUnit.Point);
                y = (float) pageBase.getSize().getHeight()/ 2;
                pageBase.getCanvas().drawImage(PdfImage.fromImage(image), new Point2D.Float(x, y));
            }
            //保存结果文档
            doc.saveToFile("output/AddSeal.pdf");
        }
    
        //定义GetImage方法，根据PDF页数分割印章图片
        static BufferedImage[] GetImage(int num) throws IOException {
            String originalImg = "C:\\Users\\Test1\\Desktop\\Image.png";
            BufferedImage image = ImageIO.read(new File(originalImg));
            int rows = 1;
            int cols = num;
            int chunks = rows * cols;
            int chunkWidth = image.getWidth() / cols;
            int chunkHeight = image.getHeight() / rows;
            int count = 0;
            BufferedImage[] imgs = new BufferedImage[ chunks ];
            for (int x = 0; x < rows; x++) {
                for (int y = 0; y < cols; y++) {
                    imgs[ count ] = new BufferedImage(chunkWidth, chunkHeight, image.getType());
                    Graphics2D gr = imgs[ count++ ].createGraphics();
                    gr.drawImage(image, 0, 0, chunkWidth, chunkHeight,
                            chunkWidth * y, chunkHeight * x,
                            chunkWidth * y + chunkWidth, chunkHeight * x + chunkHeight, Color.WHITE,null);
                    gr.dispose();
                }
            }
            return imgs;
        }
    }

骑缝章添加效果：

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L0VpY2VibHVl_size_16_color_FFFFFF_t_70 1][]

（完）

[jar]: https://www.e-iceblue.cn/Downloads/Free-Spire-PDF-JAVA.html
[Link 1]: https://www.e-iceblue.cn/licensing/install-spirepdf-for-java-from-maven-repository.html
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L0VpY2VibHVl_size_16_color_FFFFFF_t_70]: /images/1604076367157.png
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L0VpY2VibHVl_size_16_color_FFFFFF_t_70 1]: /images/1604076356267.png