使用pdfbox 把pdf转成图片

使用pdfbox 把pdf转成图片

public class PdfUtils {public static byte[] pdfToImage (byte[] bytes){BufferedImage pdfImage=null;try{PDDocument doc = PDDocument.load(bytes);PDFRenderer pdfRenderer = new PDFRenderer(doc);//获取总页数int pageCount&#NumberOfPages();int y=0;List<BufferedImage> list = new ArrayList<>(pageCount);int totalHeight=0;int widthOne=0;if(pageCount>0){for (int i = 0; i < pageCount; i++) {PDPage page = Page(i);PDRectangle cropBox = CropBox();int width =(int) Width();if(widthOne==0){widthOne=width;}//每页pdf内容BufferedImage bim = derImageWithDPI(i, 80, ImageType.RGB);totalHeight+&#Height();list.add(bim);}}for (BufferedImage bim : list) {//如果是第一页需要初始化if(Objects.isNull(pdfImage)){//创建一个总高、总宽的图片缓冲区pdfImage = new BufferedImage(widthOne, totalHeight, BufferedImage.TYPE_INT_RGB);}Graphics().drawImage(bim,0,y,null);y+&#Height();}doc.close();if(pdfImage!=null){ByteArrayOutputStream baos = new ByteArrayOutputStream();ImageIO.write(pdfImage,"png",baos);baos.flush();byte[] bytes1 = ByteArray();return  bytes1;}return null;}catch ( Exception e){e.printStackTrace();}finally {if(pdfImage!=null){Graphics().dispose();}}return null;}
}

其中 new BufferedImage(widthOne, totalHeight, BufferedImage.TYPE_INT_RGB); 如果pdf页数过多图片高度过大，会导致内存溢出