相关依赖

        <!-- https://mvnrepository.com/artifact/com.itextpdf/itextpdf --><dependency><groupId>com.itextpdf</groupId><artifactId>itextpdf</artifactId><version>5.5.13</version></dependency><!-- https://mvnrepository.com/artifact/com.itextpdf/itext-asian --><dependency><groupId>com.itextpdf</groupId><artifactId>itext-asian</artifactId><version>5.2.0</version></dependency>

//设置字体

此行报错删除maven中的-itext-asian文件重新加载依赖

BaseFont font = BaseFont.createFont("STSong-Light", "UniGB-UCS2-H", BaseFont.NOT_EMBEDDED);

测试代码

import com.itextpdf.text.BaseColor;
import com.itextpdf.text.Element;
import com.itextpdf.text.pdf.*;import java.io.FileOutputStream;public class TestWaterPrint {public static void main(String[] args) throws Exception {addWaterMark("H:/b.pdf", "H:/a.pdf", "测试测试", 2);}/*** pdf生成水印** @param srcPdfPath       插入前的文件路径* @param tarPdfPath       插入后的文件路径* @param WaterMarkContent 水印内容* @param numberOfPage     每页需要插入的条数* @throws Exception*/public static void addWaterMark(String srcPdfPath, String tarPdfPath, String WaterMarkContent, int numberOfPage) throws Exception {PdfReader reader = new PdfReader(srcPdfPath);PdfStamper stamper = new PdfStamper(reader, new FileOutputStream(tarPdfPath));PdfGState gs = new PdfGState();//设置字体BaseFont font = BaseFont.createFont("STSong-Light", "UniGB-UCS2-H", BaseFont.NOT_EMBEDDED);// 设置透明度gs.setFillOpacity(0.4f);int total = reader.getNumberOfPages() + 1;PdfContentByte content;for (int i = 1; i < total; i++) {content = stamper.getOverContent(i);content.beginText();content.setGState(gs);//水印颜色content.setColorFill(BaseColor.DARK_GRAY);//水印字体样式和大小content.setFontAndSize(font, 35);//插入水印  循环每页插入的条数for (int j = 0; j < numberOfPage; j++) {content.showTextAligned(Element.ALIGN_CENTER, WaterMarkContent, 300, 200 * (j + 1), 30);}content.endText();}stamper.close();System.out.println("PDF水印添加完成！");}
}