java使用BufferedImage给PPT添加背景图片水印代码，水印支持换行

要使用Java中的BufferedImage给PPT添加背景图片水印，并支持换行，您可以使用Apache POI库来操作PPT文件。以下是一个示例代码：

import org.apache.poi.sl.usermodel.*;
import org.apache.poi.xslf.usermodel.*;
import org.apache.poi.util.IOUtils;

import java.awt.*;
import java.awt.geom.Rectangle2D;
import java.awt.image.BufferedImage;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import javax.imageio.ImageIO;

public class AddBackgroundImageToPPT {
    public static void main(String[] args) {
        String pptFilePath = "path/to/presentation.pptx";
        String backgroundImageFilePath = "path/to/background_image.jpg";
        String watermarkText = "Your Watermark Text\nSecond Line";
        
        try (FileInputStream inputStream = new FileInputStream(pptFilePath);
             FileOutputStream outputStream = new FileOutputStream("path/to/output.pptx")) {

            XMLSlideShow ppt = new XMLSlideShow(inputStream);
            XSLFSlideMaster slideMaster = ppt.getSlideMasters().get(0);

            // 加载背景图片
            BufferedImage backgroundImage = ImageIO.read(new File(backgroundImageFilePath));
            int slideWidth = (int) slideMaster.getPageSize().getWidth();
            int slideHeight = (int) slideMaster.getPageSize().getHeight();
            
            // 创建一个带有背景图片的PPT背景
            XSLFBackground background = slideMaster.getBackground();
            background.clear();
            background.setFillType(BackgroundFill.FILL_PICTURE);
            background.setPictureData(ppt.addPicture(IOUtils.toByteArray(backgroundImage), PictureData.PictureType.JPEG));
            background.setAnchor(new Rectangle2D.Double(0, 0, slideWidth, slideHeight));

            // 遍历每一页PPT，添加背景图片水印
            for (XSLFSlide slide : ppt.getSlides()) {
                XSLFSlideLayout slideLayout = slide.getSlideLayout();
                XSLFTextBox textBox = slideLayout.createTextBox();
                textBox.setText(watermarkText);
                textBox.setAnchor(new Rectangle2D.Double(0, 0, slideWidth, slideHeight));
                
                // 设置文本框样式
                XSLFTextParagraph paragraph = textBox.getTextParagraphs().get(0);
                XSLFTextRun textRun = paragraph.getTextRuns().get(0);
                textRun.setFontSize(36);
                textRun.setFontColor(Color.GRAY);
                textRun.setBold(true);
                textRun.setItalic(true);
                
                // 将文本框添加到幻灯片
                slide.getShapes().add(textBox);
            }

            ppt.write(outputStream);
            ppt.close();
        } catch (IOException | IllegalArgumentException e) {
            e.printStackTrace();
        }
    }
}

请确保您已将Apache POI库的依赖项添加到您的项目中。您可以在Maven或Gradle中添加以下依赖项：

<dependency>
    <groupId>org.apache.poi</groupId>
    <artifactId>poi-ooxml</artifactId>
    <version>4.1.2</version>
</dependency>

这是一个简单的示例，通过在文本中使用换行符来支持水印的换行。您可以根据您的需求进行修改和扩展。希望对您有所帮助！