public class SmallImage {        /**     * PDF缩略图    * @Method PDFToImage    * @Description TODO    * @param pdfpath PDF文档路径    * @param outImagePath 输出图片的文件夹路径，如果没有会自动创建    * @param imgWidth 缩略图宽度，0按照文档宽度    * @param imgHeight 缩略图高度，0按照文档高度    * @param pageNum 需要打印的页数，0打印所有，其他打印对应页数    * @Return void     */    public static void PDFToImage(String pdfPath, String outImgPath, int imgWidth, int imgHeight, int outImgNum){        try {            File file = new File(pdfPath);            if(!file.exists()){                System.out.println("PDF文档不存在！");            }            RandomAccessFile raf = new RandomAccessFile(file, "r");//r表示只读            FileChannel channel = raf.getChannel();            ByteBuffer buf = channel.map(FileChannel.MapMode.READ_ONLY, 0, channel.size());              PDFFile pdffile = new PDFFile(buf);                        System.out.println("PDF页数： " + pdffile.getNumPages());                          int outImageNum = pdffile.getNumPages();            if(outImgNum!=0){                outImageNum = outImgNum;            }            for (int i=1; i<=outImageNum; i++){                PDFPage page = pdffile.getPage(i);                Rectangle rect = new Rectangle(0, 0, (int) page.getBBox().getWidth(), (int) page.getBBox().getHeight());                 int width = rect.width;                int height = rect.height;                if(imgWidth!=0){                    width = imgWidth;                }                if(imgHeight!=0){                    height = imgHeight;                }                Image img = page.getImage(width, height,rect,null,true,true);                BufferedImage tag = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB);                  tag.getGraphics().drawImage(img, 0, 0, width, height, null);                File imgPath = new File(outImgPath);                //如果图输出文件夹不存在，创建文件夹                if(!imgPath.exists()){                    imgPath.mkdir();                }                FileOutputStream out = new FileOutputStream(imgPath.toString()+"//"+file.getName()+"_"+i+".jpg"); // 输出到文件流                  JPEGImageEncoder encoder = JPEGCodec.createJPEGEncoder(out);                  encoder.encode(tag); // JPEG编码                  out.close();              }          } catch (Exception e) {            e.printStackTrace();        }    }        public static void main(String[] args) {        SmallImage.PDFToImage("c://2.pdf", "c://picture", 240, 338, 1);    }}