JAVA 给 PDF文件加水印 （满屏文印和中间文印均有）

1.jar包   

Itext相关便可java

连接：https://pan.baidu.com/s/1DRAnRxT037hibWey5uJ_AA 提取码：f3q1  
spa

2.源码

注：注释掉的是满屏文印版，没注释的是大文字中间文印版  ，想用什么版本调换注释就好了。code

package com.wdkj.util;

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

import javax.swing.JLabel;

import com.itextpdf.text.BaseColor;
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;
/** * PDF加水印 * @author sunkuang * */
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();
			// 设置透明度
			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;
			//int numi = 0 ;
			//int numj = 0 ;
			//int numk = 0 ;
			
			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, 50);  //设置大小
				// 设置水印颜色
				under.setColorFill(BaseColor.BLACK);
				
				// 水印文字成30度角倾斜
				// 你能够为所欲为的改你本身想要的角度
				/*for (int height = interval + textH; height < pageRect .getHeight(); height = height + textH * 3) { numj ++ ; for (int width = interval + textW; width < pageRect .getWidth() + textW; width = width + textW * 2) { numk ++ ; under.showTextAligned(Element.ALIGN_LEFT, waterMarkName, width - textW, height - textH, 30); } } */
				under.showTextAligned(Element.ALIGN_LEFT,
						waterMarkName, reader.getPageSize(i).getWidth()/2-120, reader.getPageSize(i).getHeight()/2-80,
						45);
			
				// 添加水印文字
				under.endText();
			}
			//System.out.println( numi);
			//System.out.println( numj);
			//System.out.println( numk);
			// 说三遍
			// 必定不要忘记关闭流
			// 必定不要忘记关闭流
			// 必定不要忘记关闭流
			stamper.close();
			reader.close();
		} catch (Exception e) {
			e.printStackTrace();
		}
	}

}复制代码