如何使用Java平铺PDF文档中的页面内容。（How to tile a page content in a PDF document using Java.）

问题描述 (Problem Description)

如何使用Java平铺PDF文档中的页面内容。

解决方案 (Solution)

以下是使用Java在pdf中平铺页面内容的程序。

import com.itextpdf.kernel.geom.AffineTransform; 
import com.itextpdf.kernel.geom.PageSize; 
import com.itextpdf.kernel.geom.Rectangle; 
import com.itextpdf.kernel.pdf.PdfDocument; 
import com.itextpdf.kernel.pdf.PdfPage; 
import com.itextpdf.kernel.pdf.PdfReader; 
import com.itextpdf.kernel.pdf.PdfWriter; 
import com.itextpdf.kernel.pdf.canvas.PdfCanvas; 
import com.itextpdf.kernel.pdf.xobject.PdfFormXObject;  
public class TilingPDFPages { 
   public static void main(String args[]) throws Exception { 
      //Creating a PdfWriter object 
      String dest = "C:/itextExamples/tilingPdfPages.pdf"; 
      PdfWriter writer = new PdfWriter(dest);      
      //Creating a PdfReader 
      String src = "C:/itextExamples/pdfWithImage.pdf"; 
      PdfReader reader = new PdfReader(src);        
      //Creating a PdfDocument objects 
      PdfDocument destpdf = new PdfDocument(writer);         
      PdfDocument srcPdf = new PdfDocument(reader); 
      //Opening a page from the existing PDF 
      PdfPage origPage = srcPdf.getPage(1); 
      //Getting the page size 
      Rectangle orig = origPage.getPageSizeWithRotation();    
      //Getting the size of the page 
      PdfFormXObject pageCopy = origPage.copyAsFormXObject(destpdf);  
      //Tile size 
      Rectangle tileSize = PageSize.A4.rotate(); 
      AffineTransform transformationMatrix = AffineTransform.getScaleInstance( 
         tileSize.getWidth()/orig.getWidth() * 2f, 
         tileSize.getHeight()/orig.getHeight() * 2f); 
      //The first tile 
      PdfPage page = destpdf.addNewPage(PageSize.A4.rotate()); 
      PdfCanvas canvas = new PdfCanvas(page); 
      canvas.concatMatrix(transformationMatrix); 
      canvas.addXObject(pageCopy, 0, -orig.getHeight()/2f); 
      //The second tile 
      page = destpdf.addNewPage(PageSize.A4.rotate()); 
      canvas = new PdfCanvas(page); 
      canvas.concatMatrix(transformationMatrix); 
      canvas.addXObject(pageCopy, -orig.getWidth()/2f, -orig.getHeight()/2f); 
      //The third tile 
      page = destpdf.addNewPage(PageSize.A4.rotate()); 
      canvas = new PdfCanvas(page); 
      canvas.concatMatrix(transformationMatrix); 
      canvas.addXObject(pageCopy, 0, 0); 
      //The fourth tile 
      page = destpdf.addNewPage(PageSize.A4.rotate()); 
      canvas = new PdfCanvas(page); 
      canvas.concatMatrix(transformationMatrix); 
      canvas.addXObject(pageCopy, -orig.getWidth()/2f, 0);
      destpdf.close(); 
      srcPdf.close(); 
      System.out.println("PDF created successfully..");  
   }     
}

输出 (Output)