Java实现pdf文件添加水印，铺满全页。

因项目需要将word文件（.doc,.docx,.rtf）转换成pdf文件并添加水印，铺满全页。

现就将为pdf文件添加水印提取出来，word文件转换成pdf文件，网上的教程很多，如需需要联系我即可。

import java.awt.FontMetrics;
import java.io.FileOutputStream;

import javax.swing.JLabel;

import com.itextpdf.text.Element;
import com.itextpdf.text.Rectangle;
import com.itextpdf.text.pdf.BaseFont;
import com.itextpdf.text.pdf.PdfContentByte;
import com.itextpdf.text.pdf.PdfGState;
import com.itextpdf.text.pdf.PdfReader;
import com.itextpdf.text.pdf.PdfStamper;
import com.itextpdf.text.pdf.PdfWriter;

public class TestwaterMark {
	private static int interval = -5;   
	public static void waterMark(String inputFile,    
            String outputFile, String waterMarkName) {    
        try {    
            PdfReader reader = new PdfReader(inputFile);    
            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  
                //你可以随心所欲的改你自己想要的角度
                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();    
            }   
            //说三遍
           //一定不要忘记关闭流
          //一定不要忘记关闭流
          //一定不要忘记关闭流
            stamper.close();  
            reader.close();
        } catch (Exception e) {    
            e.printStackTrace();    
        }    
    }    

	public static void main(String[] args) {
		 waterMark("F:/exe/123.pdf", "F:/exe/456.pdf", "我是黑豆");  

	}

}

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示例图片