PDF转换图片，图片的切割，图片转换PDF以及PDF加水印等记录贴

最近项目中有一些对PDF操作的需求，包括：

PDF转变为图片；

把图片进行切割；

把图片转变回PDF；

为PDF加水印文字；

为PDF加水印图片。

这里记录一下这些方法，方便日后用到时可查，也希望可以帮助有这方面需求的小伙伴。

以下方法均为可直接运行的测试方法，复制导包就可以运行，这里测试都可以跑通。

1，PDF转变为图片

/** * @author dalin *将PDF格式的文件转换成png文件 */public class PdfToPNG {public static void main(String[] args) {String filePath = "D:\\pdf\\2.pdf";    Document document = new Document();document.setFile(filePath);float scale = 2.5f;//缩放比例float rotation = 0f;//旋转角度     for (int i = 0; i < document.getNumberOfPages(); i++) {BufferedImage image = (BufferedImage)document.getPageImage(i, GraphicsRenderingHints.SCREEN, org.icepdf.core.pobjects.Page.BOUNDARY_CROPBOX, rotation, scale);RenderedImage rendImage = image;try {  File file = new File("D:\\img\\" + i + ".png");  ImageIO.write(rendImage, "png", file); } catch (IOException e) {  e.printStackTrace();}image.flush();}document.dispose();}}

2，图片切割

/** * @author dalin *分割png文件，这里做截取png文件部分 */public class FenGePNG {    private static void splitImage() throws IOException {                    String originalImg = "D:\\img\\0.png";                // 读入大图          File file = new File(originalImg);          FileInputStream fis = new FileInputStream(file);          BufferedImage image = ImageIO.read(fis);                // 分割成4*4(16)个小图          int rows = 2;          int cols = 1;          int chunks = rows * cols;                // 计算每个小图的宽度和高度          int chunkWidth = image.getWidth() / cols;          int chunkHeight = image.getHeight() / rows;                int count = 0;          BufferedImage imgs[] = new BufferedImage[chunks];          for (int x = 0; x < rows; x++) {              for (int y = 0; y < cols; y++) {                  //设置小图的大小和类型                  imgs[count] = new BufferedImage(chunkWidth, chunkHeight, image.getType());                        //写入图像内容                  Graphics2D gr = imgs[count++].createGraphics();                  gr.drawImage(image, 0, 0,                           chunkWidth, chunkHeight,                           chunkWidth* y, chunkHeight * x,                           chunkWidth * y + chunkWidth,                          chunkHeight * x + chunkHeight, null);                  gr.dispose();              }          }                // 输出小图          for (int i = 0; i < imgs.length; i++) {              ImageIO.write(imgs[i], "jpg", new File("D:\\img\\" + "img"+i + ".jpg"));          }                    System.out.println("完成分割！");      }  public static void main(String[] args) {try {splitImage();} catch (IOException e) {e.printStackTrace();}}}

3，图片转变为PDF

/** * @author dalin  * png文件类型转为PDF类型 */public class PNGToPdf {private static void jpgToPdf(File pdfFile,File imgFile)  throws Exception {          //文件转img          InputStream is = new FileInputStream(pdfFile);          ByteArrayOutputStream baos = new ByteArrayOutputStream();          for(int i;(i=is.read())!=-1;)          {              baos.write(i);          }          baos.flush();                    //取得图像的宽和高。          Image img = Image.getInstance(baos.toByteArray());          float width = img.width();          float height = img.height();          img.setAbsolutePosition(0.0F, 0.0F);//取消偏移          System.out.println("width = "+width+"\theight"+height);                    //img转pdf          Document doc = new Document(new Rectangle(width,height));          PdfWriter pw = PdfWriter.getInstance(doc,new FileOutputStream(imgFile));          doc.open();          doc.add(img);                    //释放资源          System.out.println(doc.newPage());          pw.flush();          baos.close();          doc.close();          pw.close();      }  public static void main(String[] args) {try {jpgToPdf(new File("D:\\img\\0.png"),new File("D:\\pdf\\2new.pdf"));} catch (Exception e) {e.printStackTrace();}  }}

4，为PDF加文字水印和图片水印

public class Test {public static void main(String[] args) throws DocumentException, IOException {// 要输出的pdf文件BufferedOutputStream bos = new BufferedOutputStream(new FileOutputStream(new File("D:\\pdf\\water6.pdf")));setWatermark(bos, "D:\\pdf\\2.pdf", 16);}public static void setWatermark(BufferedOutputStream bos, String input, int permission)throws DocumentException, IOException {Rectangle pageRect = null;PdfReader reader = new PdfReader(input);PdfStamper stamper = new PdfStamper(reader, bos);int total = reader.getNumberOfPages() + 1;PdfContentByte content;Image image = Image.getInstance("D:/pdf/1.jpg");BaseFont base = BaseFont.createFont("STSong-Light", "UniGB-UCS2-H", BaseFont.EMBEDDED);PdfGState gs = new PdfGState();for (int i = 1; i < total; i++) {pageRect = stamper.getReader().getPageSizeWithRotation(i);// 计算水印X,Y坐标// float x = pageRect.getWidth() / 1;float y = pageRect.getHeight() / 1;System.out.println("这张PDF长是：" + y);// content = stamper.getOverContent(i);// 在内容上方加水印content = stamper.getUnderContent(i);// 在内容下方加水印gs.setFillOpacity(0.2f);// content.setGState(gs);content.beginText();content.setColorFill(Color.LIGHT_GRAY);content.setFontAndSize(base, 25);// content.setTextMatrix(500,500);image.setAbsolutePosition(100, 200);image.setRotationDegrees(30);content.showTextAligned(Element.ALIGN_LEFT, "XXXX防伪标志", 250, 200, 55);image.scaleToFit(200, 200);content.addImage(image);content.setColorFill(Color.BLACK);content.setFontAndSize(base, 8);content.endText();}stamper.close();}}

好了，就这些了。包基本就是iText那些