java给pdf文件添加水印。

java给pdf文件添加水印，适用于不是maven管理的普通java工程。

切记必需导入这两个架包itext-2.0.6.jar和iTextAsian.jar，为了这两个架包我没少折腾，下面有架包下载地址 架包下载地址： 链接：https://pan.baidu.com/s/1pbXavIUlfFspbpRzHtJnbQ 提取码：i9ap

public class WaterMark {
          
   
    	private static int interval = -5;
    	public static void main(String[] args) throws Exception {
          
   
    		// TODO Auto-generated method stub
    		String inputFile = "F:\123.pdf";
    		String outputFile = "F:\456.pdf";
    		String content = "root用户";
    		waterMark(inputFile, outputFile, content); 
    		//String base64String = getPDFBinary(outputFile);
    		//System.out.println(base64String);
    		//getText(outputFile);
    	}
    	
    	//给PDF添加水印
    	//inputFile 文件路径+名称
    	//outputFile 添加水印后输出文件保存的路径+名称
    	//waterMarkName 添加水印的内容
    	public static void waterMark(String inputFile,String outputFile, String waterMarkName) {
          
       
            try {
          
       
                PdfReader reader = new PdfReader(inputFile);  //切记这里的参数是文件的路径 ，路径必须是双斜杠的如F:\123.pdf，不能是F:/123.pdf 或者F:123.pdf
                PdfStamper stamper = new PdfStamper(reader, new FileOutputStream(    
                        outputFile));    
                  
                BaseFont base = BaseFont.createFont("STSong-Light", "UniGB-UCS2-H",   BaseFont.EMBEDDED);  
                  
                Rectangle pageRect = null;  
                PdfGState gs = new PdfGState();  
                gs.setFillOpacity(0.3f);  
                gs.setStrokeOpacity(0.4f);  
                int total = reader.getNumberOfPages() + 1;   
                  
                JLabel label = new JLabel();  
                FontMetrics metrics;  
                int textH = 0;   
                int textW = 0;   
                label.setText(waterMarkName);   
                metrics = label.getFontMetrics(label.getFont());   
                textH = metrics.getHeight();
                textW = metrics.stringWidth(label.getText());  
                    
                PdfContentByte under;    
                for (int i = 1; i < total; i++) {
          
      
                    pageRect = reader.getPageSizeWithRotation(i);   
                    under = stamper.getOverContent(i);   
                    under.saveState();  
                    under.setGState(gs);  
                    under.beginText();    
                    under.setFontAndSize(base, 20);    
                   
                    // 水印文字成30度角倾斜  
                    for (int height = interval + textH; height < pageRect.getHeight();  
                            height = height + textH*3) {
          
       
                        for (int width = interval + textW; width < pageRect.getWidth() + textW;   
                                width = width + textW*2) {
          
     
                    under.showTextAligned(Element.ALIGN_LEFT  
                            , waterMarkName, width - textW,  
                            height - textH, 30);  
                        }  
                    }  
                    // 添加水印文字    
                    under.endText();    
                }   
                stamper.close();  
                reader.close();
            } catch (Exception e) {
          
       
                e.printStackTrace();    
            }    
        }
   }