Java 在PDF中添加骑缝章示例解析

<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>

import com.spire.pdf.*;
import com.spire.pdf.graphics.PdfGraphicsUnit;
import com.spire.pdf.graphics.PdfImage;
import com.spire.pdf.graphics.PdfUnitConvertor;

import javax.imageio.ImageIO;
import java.awt.*;
import java.awt.geom.Point2D;
import java.awt.image.BufferedImage;
import java.io.File;
import java.io.IOException;

public class AcrossPageSeal {
 public static void main(String[] args) throws IOException {
  //加载测试文档
  PdfDocument pdf = new PdfDocument();
  pdf.loadFromFile("test.pdf");

  //获取分割后的印章图片
  BufferedImage[] images = GetImage(pdf.getPages().getCount());
  float x = 0;
  float y = 0;

  //实例化PdfUnitConvertor类
  PdfUnitConvertor convert = new PdfUnitConvertor();
  PdfPageBase pageBase;
  //将图片绘制到PDF页面上的指定位置
  for (int i = 0; i < pdf.getPages().getCount(); i++)
  {
   BufferedImage image= images[ i ];
   pageBase = pdf.getPages().get(i);
   x = (float)pageBase.getSize().getWidth() - convert.convertUnits(image.getWidth(), PdfGraphicsUnit.Point, PdfGraphicsUnit.Pixel) + 40;
   y = (float) pageBase.getSize().getHeight()/ 2;
   pageBase.getCanvas().drawImage(PdfImage.fromImage(image), new Point2D.Float(x, y));
  }

  //保存PDF文档
  pdf.saveToFile("Result.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 = "seal.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;
 }

}