Flying HTML生成PDF添加水印

HTML转PDF并添加水印
java 复制代码
<!-- 用于生成PDF -->
<dependency>
    <groupId>org.xhtmlrenderer</groupId>
    <artifactId>flying-saucer-pdf</artifactId>
    <version>9.1.20</version>
</dependency>


import java.io.File;
import java.io.FileOutputStream;
import java.util.Random;
import org.xhtmlrenderer.pdf.ITextRenderer;
import com.lowagie.text.Element;
import com.lowagie.text.Font;
import com.lowagie.text.Image;
import com.lowagie.text.Phrase;
import com.lowagie.text.Rectangle;
import com.lowagie.text.pdf.BaseFont;
import com.lowagie.text.pdf.ColumnText;
import com.lowagie.text.pdf.PdfContentByte;
import com.lowagie.text.pdf.PdfGState;
import com.lowagie.text.pdf.PdfReader;
import com.lowagie.text.pdf.PdfStamper;

public class HtmlToPdfConverter {
     
    public static void main(String[] args) throws Exception {
        String htmlContent = "<html><head><style>body { font-family: 'SimHei', sans-serif; }</style></head><body><h1>我的标题</h1><p>测试pdf</p></body></html>";
        // 使用Flying Saucer渲染HTML到临时PDF文件
        File tempFile = File.createTempFile("temp", ".pdf");
        ITextRenderer renderer = new ITextRenderer();
        //设置字体
        File fontFile = new File("F:\\weixin\\emlsr\\src\\main\\resources\\font\\simhei.ttf");
        BaseFont baseFont = BaseFont.createFont(fontFile.getAbsolutePath(), BaseFont.IDENTITY_H, BaseFont.NOT_EMBEDDED);
        renderer.getFontResolver().addFont(fontFile.getAbsolutePath(), baseFont.getEncoding(), BaseFont.NOT_EMBEDDED);

        //生成数据
        renderer.setDocumentFromString(htmlContent);
        renderer.layout();
        renderer.createPDF(new FileOutputStream(tempFile));
        
        // 用iText打开临时PDF文件，并添加水印
        PdfGState gs = new PdfGState();
        gs.setFillOpacity(0.5f); // 设置为 50% 的透明度
        Font font = new Font(baseFont, 30, Font.NORMAL);
        PdfReader reader = new PdfReader(tempFile.getAbsolutePath());
        PdfStamper stamper = new PdfStamper(reader, new FileOutputStream("c:\\output.pdf"));
        
        //水印图片(001)
        //Image watermarkImage = Image.getInstance("C:\\1.jpg");
        //float scale = 0.2f; // 水印图片缩放比例
        //watermarkImage.scaleAbsolute(watermarkImage.getWidth() * scale, watermarkImage.getHeight() * scale);

        
        //水印平铺(002)
        // 获取一个页面尺寸作为参考来计算水印图片的缩放比例
        //Image watermarkImage = Image.getInstance("C:\\1.jpg");
        // 设置水印图片平铺的宽度和高度（例如：将水印图片设为100x100像素）
        //float tileWidth = 100f;
        //float tileHeight = 100f;
        //watermarkImage.scaleAbsolute(tileWidth, tileHeight);

        
        //水印随机平铺3个(003)
        Image watermarkImage = Image.getInstance("C:\\1.jpg");
        // 设置水印图片平铺的宽度和高度（例如：将水印图片设为100x100像素）
        float tileWidth = 100f;
        float tileHeight = 100f;
        Random random = new Random(); // 创建一个随机数生成器

        int n = reader.getNumberOfPages();
        for (int i = 1; i <= n; i++) {
            PdfContentByte underContent = stamper.getUnderContent(i);
            underContent.setGState(gs);
            // 字体添加透明度
            ColumnText.showTextAligned(underContent, Element.ALIGN_CENTER,
                    new Phrase("水印文字",font),
                    reader.getPageSize(i).getWidth() / 2,
                    reader.getPageSize(i).getHeight() / 2,
                    45); // 角度可调整水印倾斜程度
            
            
            
            // 获取页面尺寸并计算水印位置(001)
            //Rectangle pageRect = reader.getPageSizeWithRotation(i);
            //float x = (pageRect.getWidth() - watermarkImage.getScaledWidth()) / 2;
            //float y = (pageRect.getHeight() - watermarkImage.getScaledHeight()) / 2;
            // 添加水印图片
            //underContent.addImage(watermarkImage, watermarkImage.getWidth(), 0, 0, watermarkImage.getHeight(), x, y);
            
            
            
            //水印平铺(002)满屏
            //Rectangle pageRect = reader.getPageSizeWithRotation(i);
            // 计算并添加水印图片的位置（按照平铺效果）
            //for (float x = 0; x < pageRect.getWidth(); x += tileWidth) {
            //    for (float y = 0; y < pageRect.getHeight(); y += tileHeight) {
            //        underContent.addImage(watermarkImage, tileWidth, 0, 0, tileHeight, x, y);
            //    }
            //}
            
            
            //(003)
            Rectangle pageRect = reader.getPageSizeWithRotation(i);
            // 计算并添加三个随机位置的水印图片
            for (int j = 0; j < 3; j++) {
                // 随机计算X和Y坐标
                float x = random.nextFloat() * (pageRect.getWidth() - tileWidth);
                float y = random.nextFloat() * (pageRect.getHeight() - tileHeight);
                underContent.addImage(watermarkImage, tileWidth, 0, 0, tileHeight, x, y);
            }

        }
        
        
        
        // 关闭
        stamper.close();
        reader.close();
        tempFile.delete();
        System.out.println("带有水印的PDF文件已生成至： output.pdf");
    }
}