java 给pdf加水印

柔光的暖阳◎ 2023-06-21 10:21 38阅读 0赞

#### 1、加入依赖 ####

<dependency>
        <groupId>com.itextpdf</groupId>
        <artifactId>itext-asian</artifactId>
        <version>5.2.0</version>
    </dependency>
    <dependency>
        <groupId>com.itextpdf</groupId>
        <artifactId>itextpdf</artifactId>
        <version>5.4.3</version>
    </dependency>

#### 2、上代码 ####

import com.itextpdf.text.DocumentException;
    import com.itextpdf.text.Image;
    import com.itextpdf.text.pdf.PdfContentByte;
    import com.itextpdf.text.pdf.PdfReader;
    import com.itextpdf.text.pdf.PdfStamper;
    
    /** * 将图片印到授权pdf中，若成功返回true，失败则返回false * @param imgBytes 图片字节码 * @param pdfTemplatePath pdf存放路径 * @param savePath 合成后pdf保存路径 * @return */
      public boolean pdfAddWatermark(byte[] imgBytes, String pdfTemplatePath, String savePath) throws BusinessException { 
          PdfReader reader = null;
          PdfStamper stamp = null;
          Image img = null;
          try { 
              String filePath = savePath.substring(0, savePath.lastIndexOf('/'));
              File file = new File(filePath);
              if(!file.exists()) { 
                  file.mkdirs();
              }
              reader = new PdfReader(pdfTemplatePath, "PDF".getBytes());
              stamp = new PdfStamper(reader, new FileOutputStream(savePath));  //加了水印后要输出的路径
              img = Image.getInstance(imgBytes);
    
              int pageSize = reader.getNumberOfPages();          //原pdf文件的总页数
              img.setAbsolutePosition(350, 300);          //印章位置
              img.scalePercent(20);                           //印章大小
              for (int i = 1; i <= pageSize; i++) { 
    // PdfContentByte under = stamp.getUnderContent(i); //背景被覆盖
                  //文字被覆盖
                  PdfContentByte under = stamp.getOverContent(i);
                  //添加电子印章
                  under.addImage(img);
              }
              return true;
          } catch (Exception e) { 
              e.printStackTrace();
          } finally { 
              try { 
                  stamp.close();
                  reader.close();
              } catch (DocumentException e) { 
                  e.printStackTrace();
              } catch (IOException e) { 
                  e.printStackTrace();
              }
          }
      }