2

我尝试通过PDFBox读取现有的 PDF 文档，提取 Tj 运算符，然后更改单词 (Tw)、字符 (Tc)、水平间距 (Tz) 之间的间距，以生成修改后的文档。我的问题是当我编辑修改后的文档以读取修改后的文件结构时，Tc、Tw、Tz 运算符的值发生了变化。防止这种变化的解决方案是什么？

让我们考虑这段代码：

public static void main(String[] args) throws IOException, COSVisitorException {
        // TODO code application logic here   
           tes= new Test1();
           tes.CreatePdf(src);
           PDDocument doc ;
           doc = PDDocument.load("doc.pdf");
           List pages = doc.getDocumentCatalog().getAllPages();  
           for (int i = 0; i < pages.size(); i++)  {
              PDPage page = (PDPage) pages.get(i);  
              PDStream contents = page.getContents();  
           COSDictionary dic= page.getCOSDictionary();
          System.out.println (dic.getCOSObject());
              PDFStreamParser parser = new PDFStreamParser(contents.getStream());
              parser.parse();  
              List tokens = parser.getTokens();  
              System.out.println(tokens);
                for (int j = 0; j < tokens.size(); j++)  
            {  
                  Object next = tokens.get(j); 
                     if (next instanceof PDFOperator)  {
                       PDFOperator op = (PDFOperator) next;  
                    // Tj and TJ are the two operators that display strings in a PDF  
                             if (op.getOperation().equals("Tj"))  
                    { 


            tokens.set(j-1, COSFloat.get("0.00416145"));
            tokens.set(j, PDFOperator.getOperator("Tc"));
            tokens.add(++j, new COSString("he"));
            tokens.add(++j, PDFOperator.getOperator("Tj"));
             tokens.add(++j, COSFloat.get("0.001611215"));
            tokens.add(++j, PDFOperator.getOperator("Tc"));
            tokens.add(++j, COSFloat.get("0.0067152"));
            tokens.add(++j, PDFOperator.getOperator("Tw"));
             tokens.add(++j, new COSString("llo w"));
             tokens.add(++j, PDFOperator.getOperator("Tj"));
             tokens.add(++j, COSFloat.get("100.001410144"));
             tokens.add(++j, PDFOperator.getOperator("Tz"));
            tokens.add(++j, new COSString("orld"));
            tokens.add(++j, PDFOperator.getOperator("Tj"));


                    }
                 }      
            }
                // now that the tokens are updated we will replace the page content stream.
            PDStream updatedStream = new PDStream(doc);  
            OutputStream out = updatedStream.createOutputStream();  
            ContentStreamWriter tokenWriter = new ContentStreamWriter(out);  
            tokenWriter.writeTokens(tokens);  
            page.setContents(updatedStream);

    }

      doc.save("a.pdf"); 
      doc.close();  
    }

This file structure is obtained as follow:
6 0 obj
<<
/Length 8 0 R
>>
stream
BT
 /F0 12 Tf
 15 385 Td
 0.0041614501 Tc
 (he) Tj
 0.0016112149 Tc
 0.0067151999 Tw
 (llo w) Tj
 100.001411438 Tz
 (orld) Tj
 ET

endstream
endobj

此致，

4

0 回答 0