在word生成pdf后，或者上传pdf文件，用户希望给pdf文档添加水印信息，具体代码如下
一. 首先pom中需要引入
<!-- PDF水印--><dependency><groupId>com.itextpdf</groupId><artifactId>itextpdf</artifactId><version>5.5.13</version></dependency><!-- 中文字体 --><dependency><groupId>com.itextpdf</groupId><artifactId>itext-asian</artifactId><version>5.2.0</version></dependency>
核心代码如下，写在某个 service 下面
public void signPdf(InputStream is, Supplier<OutputStream> os, List<WaterMarkInfoRequest> signList) {PdfStamper stamper = null;PdfReader reader = null;try {reader = new PdfReader(is);stamper = new PdfStamper(reader, os.get());for (WaterMarkInfoRequest s : signList) {TextWaterMarkRequest textWaterMark = s.getTextWaterMark();if (textWaterMark != null) {//添加文字BaseFont baseFont;try {baseFont = BaseFont.createFont("STSong-Light", "UniGB-UCS2-H", BaseFont.NOT_EMBEDDED);} catch (DocumentException | IOException e) {log.info("pdf签名获取字体信息异常:{}", e.getMessage(), e);throw new BusinessException(IO_ERROR.toErrorInfos("pdf签名获取字体信息异常"));}PdfContentByte content = stamper.getOverContent(textWaterMark.getPageNo());PdfGState gState = new PdfGState();//设置透明度gState.setFillOpacity(textWaterMark.getAlpha());content.setGState(gState);content.beginText();//设置字体content.setFontAndSize(baseFont, textWaterMark.getFontSize());//设置颜色content.setColorFill(new BaseColor(0xFF << 24 | Integer.parseInt(textWaterMark.getFontColor(), 16)));//设置水印内容和位置content.showTextAligned(Element.ALIGN_MIDDLE, textWaterMark.getText(), textWaterMark.getIntervalVertical(), textWaterMark.getIntervalHorizontal(), 0f);content.endText();}ImageWaterMarkRequest imageWaterMark = s.getImageWaterMark();if (imageWaterMark != null) {//添加图片PdfContentByte content = stamper.getOverContent(imageWaterMark.getPageNo());PdfGState gState = new PdfGState();//设置透明度gState.setFillOpacity(imageWaterMark.getAlpha());//imageImage image = Image.getInstance(EncryptUtil.base64DecoderToBytes(imageWaterMark.getBase64Str()));image.setAbsolutePosition(imageWaterMark.getPositionX(), imageWaterMark.getPositionY());if (imageWaterMark.getScaleAbsoluteX() != null && imageWaterMark.getScaleAbsoluteY() != null) {image.scaleToFit(imageWaterMark.getScaleAbsoluteX(), imageWaterMark.getScaleAbsoluteY());} else if (imageWaterMark.getScalePercent() != null && imageWaterMark.getScalePercent() > 0) {image.scalePercent(imageWaterMark.getScalePercent());}content.addImage(image);content.stroke();}}} catch (Exception e) {e.printStackTrace();log.info("添加签名失败：{}", e.getLocalizedMessage(), e);WM_WRITE_ERR.throwException();} finally {if (null != stamper) {try {stamper.close();} catch (Exception e) {log.info("关闭失败：{}", e.getMessage(), e);}}if (null != reader) {reader.close();}}}
用到的实体类
public class ImageWaterMarkRequest{@ApiModelProperty(value = "需要添加的页码，默认所有页码都添加")private Integer pageNo;@ApiModelProperty(value = "水平位置 左下角坐标(0,0)")private Integer positionX;@ApiModelProperty(value = "垂直位置 左下角坐标(0,0)")private Integer positionY;@ApiModelProperty(value = "指定图像宽度 ")private Integer scaleAbsoluteX;@ApiModelProperty(value = "指定图像高度 ")private Integer scaleAbsoluteY;@ApiModelProperty(value = "缩放比例 与指定尺寸冲突 优先使用指定图像尺寸")private Integer scalePercent;@ApiModelProperty(value = "图片的二进制数据")@NotNullprivate String base64Str;@ApiModelProperty(value = "透明度 0--1")private Float alpha;@ApiModelProperty(value = "透明度 0--1",hidden = true)private Float opacity;@ApiModelProperty(value = "是否水印打在最顶层 默认true")private Boolean isTop;}
public class WaterMarkInfoRequest {@ApiModelProperty(value = "文字水印信息")private TextWaterMarkRequest textWaterMark;@ApiModelProperty(value = "图片水印信息")private ImageWaterMarkRequest imageWaterMark;}
方法测试
import java.io.InputStream;import java.io.OutputStream;import java.nio.file.Files;import java.nio.file.Paths;import java.util.ArrayList;public class PdfWaterMarkServiceImplTest {public static void main(String[] args) throws Exception {InputStream is = Files.newInputStream(Paths.get("/Users/cong/Downloads/a.pdf"));OutputStream outputStream = Files.newOutputStream(Paths.get("/Users/cong/Downloads/q-5.pdf"));ArrayList<WaterMarkInfoRequest> requests = new ArrayList<>();WaterMarkInfoRequest waterMarkInfo = addSign(1);WaterMarkInfoRequest waterMarkInfo2 = addSign(1);requests.add(waterMarkInfo);requests.add(waterMarkInfo2);//调用你自己服务的pdf水印方法new PdfWaterMarkServiceImpl().signPdf(is, () -> outputStream, requests);outputStream.close();}private static WaterMarkInfoRequest addSign(Integer pageNum) {WaterMarkInfoRequest waterMarkInfo = new WaterMarkInfoRequest();ImageWaterMarkRequest imageWaterMark = new ImageWaterMarkRequest();imageWaterMark.setPageNo(pageNum);imageWaterMark.setPositionY(200);imageWaterMark.setPositionX(200);imageWaterMark.setTop(true);imageWaterMark.setAlpha(1.0f);imageWaterMark.setBase64Str("图片base64");waterMarkInfo.setImageWaterMark(imageWaterMark);TextWaterMarkRequest textWaterMark = new TextWaterMarkRequest();textWaterMark.setText("我是一个水印");textWaterMark.setRotation(0);textWaterMark.setAlpha(1.0f);textWaterMark.setFontSize(24);textWaterMark.setIntervalHorizontal(10);textWaterMark.setIntervalVertical(10);textWaterMark.setFontColor("800000");textWaterMark.setTop(true);textWaterMark.setPageNo(pageNum);waterMarkInfo.setTextWaterMark(textWaterMark);return waterMarkInfo;}}
