基于SpringBoot用iText7将HTML转成PDF添加页眉页脚水印

以下是一个使用Spring Boot和iText 7将HTML转换成PDF并添加页眉页脚水印的简单示例。

首先，添加iText 7依赖到你的pom.xml文件中：

<dependency>
    <groupId>com.itextpdf</groupId>
    <artifactId>itext7-core</artifactId>
    <version>7.1.15</version>
    <type>pom</type>
</dependency>

然后，创建一个Spring Boot服务来转换HTML到PDF：

import com.itextpdf.html2pdf.HtmlConverter;
import com.itextpdf.kernel.pdf.PdfDocument;
import com.itextpdf.kernel.pdf.PdfWriter;
import com.itextpdf.kernel.pdf.canvas.PdfCanvasProcessor;
import com.itextpdf.layout.element.IBlockElement;
import com.itextpdf.layout.element.IElement;
import com.itextpdf.layout.property.UnitValue;
import com.itextpdf.licensing.base.LicenseKey;
import org.springframework.stereotype.Service;
import java.io.*;
import java.util.List;
 
@Service
public class PdfService {
 
    static {
        LicenseKey.loadLicenseFile("path/to/itextkey.xml"); // 指定iText 7 许可证文件路径
    }
 
    public void convertHtmlToPdf(String htmlContent, String destFilePath) throws IOException {
        PdfWriter writer = new PdfWriter(destFilePath);
        PdfDocument pdf = new PdfDocument(writer);
        pdf.addEventHandler(PdfDocumentEvent.END_PAGE,
                new HeaderFooterEventHandler(pdf));
 
        // 这里添加水印
        pdf.addEventHandler(PdfDocumentEvent.ADD_PAGE,
                new WatermarkEventHandler("CONFIDENTIAL"));
 
        List<IElement> elements = HtmlConverter.convertToElements(htmlContent);
        for (IElement element : elements) {
            if (element instanceof IBlockElement) {
                pdf.add((IBlockElement) element);
            }
        }
 
        pdf.close();
        writer.close();
    }
 
    // 页眉页脚处理器
    public static class HeaderFooterEventHandler implements IEventHandler {
        private PdfDocument pdf;
 
        public HeaderFooterEventHandler(PdfDocument pdf) {
            this.pdf = pdf;
        }
 
        @Override
        public void handleEvent(Event event) {
            PdfDocumentEvent docEvent = (PdfDocumentEvent) event;
            PdfPage page = docEvent.getPage();
            Rectangle pageSize = page.getPageSize();
            PdfCanvasProcessor processor = new PdfCanvasProcessor(page.getLastContentStream(), page.getResources(), pdf);
 
            // 添加页眉页脚逻辑
            // ...
        }
    }
 
    // 水印处理器
    public static class WatermarkEventHandler implements IEventHandler {
        private String watermarkTe