java 给pdf添加文字水印

依赖使用的包：

<dependency>
   <groupId>com.itextpdf</groupId>
   <artifactId>itextpdf</artifactId>
   <version>5.5.11</version>
</dependency>

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

 

代码的实现；

package com.gxever.zvn;

import com.itextpdf.text.BaseColor;
import com.itextpdf.text.Element;
import com.itextpdf.text.Rectangle;
import com.itextpdf.text.pdf.*;

import java.io.FileOutputStream;

/**
 * @Author Lys
 * @Date 2019/8/15 13:39
 * @Version V1.0
 * @Description:
 */
public class test {

    public static void main(String[] args) throws Exception {

        waterMark("D:\pdf\123.pdf", "D:\pdf\123Demo.pdf", "仅限际恒锐智使用，其他无效");
    }

    /**
     * @param inputFile 你的PDF文件地址
     * @param outputFile 添加水印后生成PDF存放的地址
     * @param waterMarkName 你的水印
     * @return
     */
    public static boolean waterMark(String inputFile,
                                    String outputFile, String waterMarkName) {
        try {
            PdfReader reader = new PdfReader(inputFile);
            PdfStamper stamper = new PdfStamper(reader, new FileOutputStream(
                    outputFile));
            //这里的字体设置比较关键，这个设置是支持中文的写法
            BaseFont base = BaseFont.createFont("STSong-Light",
                    "UniGB-UCS2-H", BaseFont.NOT_EMBEDDED);// 使用系统字体
            int total = reader.getNumberOfPages() + 1;

            PdfContentByte under;
            Rectangle pageRect = null;
            for (int i = 1; i < total; i++) {
                pageRect = stamper.getReader().
                        getPageSizeWithRotation(i);
                // 计算水印X,Y坐标
                float x = pageRect.getWidth()/10;
                float y = pageRect.getHeight()/10-10;
                // 获得PDF最顶层
                under = stamper.getOverContent(i);
                under.saveState();
                // set Transparency
                PdfGState gs = new PdfGState();
                // 设置透明度为0.2
                gs.setFillOpacity(1.f);
                under.setGState(gs);
                under.restoreState();
                under.beginText();
                under.setFontAndSize(base, 60);
                under.setColorFill(BaseColor.ORANGE);

                // 水印文字成45度角倾斜
                under.showTextAligned(Element.ALIGN_CENTER
                        , waterMarkName, x,
                        y, 55);
                // 添加水印文字
                under.endText();
                under.setLineWidth(1f);
                under.stroke();
            }
            stamper.close();
            return true;
        } catch (Exception e) {
            e.printStackTrace();
            return false;
        }
    }

}