Java图片转换为PDF并合成同一PDF

2023-12-10 10:02| 来源: 网络整理| 查看: 265

1.需求

将同一文件夹下的图片和PDF,转换合并为同一个PDF，并要求转换中的图片按格式排版好

2.思路调整图片，检测图片大小及方向，调整至A4大小(842×595)，寻找最佳缩放比，等比例缩放图片，为避免多次IO操作，返回BufferedImage将图片转换为PDF将文件夹下的PDF按顺序合并，得到最终的final.pdf 3.所需工具类

前两个为处理PDF的工具类，最后一个为图片处理类

com.itextpdf itextpdf 5.5.13 org.apache.pdfbox pdfbox 1.7.1 net.coobird thumbnailator 0.4.8

4.图片处理类 package JavaPdf; import net.coobird.thumbnailator.Thumbnails; import javax.imageio.ImageIO; import java.awt.*; import java.awt.image.BufferedImage; import java.awt.image.ConvolveOp; import java.awt.image.Kernel; import java.io.File; import java.io.IOException; import java.math.BigDecimal; public class ImgUtil { /** * @Author Ragty * @Description 调整图片角度并生成合适大小的图片 * @Date 16:37 2019/3/7 * @return **/ public BufferedImage rotateImage(String imgFile) throws Exception{ BufferedImage bufferedImage = null; try { if(imgFile != "" || imgFile != null){ File _img_file_ = new File(imgFile); if(_img_file_.exists()){ Integer angel = 270; BufferedImage src = ImageIO.read(_img_file_); BigDecimal height = BigDecimal.valueOf(src.getHeight()); BigDecimal width = BigDecimal.valueOf(src.getWidth()); BigDecimal bd = height.divide(width,4,BigDecimal.ROUND_CEILING); BigDecimal theValue = BigDecimal.valueOf(1.1700); if (bd.compareTo(theValue) == -1 ) { System.out.println("转换中 ..."); bufferedImage = Thumbnails.of(src).rotate(angel).scale(1).asBufferedImage(); bufferedImage = calcScale(bufferedImage); }else { bufferedImage = calcScale(src); System.out.println("宽高比合适,跳过 ..."); } //bufferedImage = getSharperPicture(bufferedImage); } } } catch (IOException e) { e.printStackTrace(); } return bufferedImage; } /** * @Author Ragty * @Description 计算最佳放缩比 * @Date 9:19 2019/3/11 * @return **/ public BufferedImage calcScale(BufferedImage bufferedImage) throws IOException{ BigDecimal standaraHeight = BigDecimal.valueOf(842); BigDecimal standaraWeight = BigDecimal.valueOf(595); BigDecimal height = BigDecimal.valueOf(bufferedImage.getHeight()); BigDecimal width = BigDecimal.valueOf(bufferedImage.getWidth()); if (height.compareTo(standaraHeight) == 1 || width.compareTo(standaraWeight) == 1) { //不符合标准，缩放 BigDecimal scaleHeight = standaraHeight.divide(height,4,BigDecimal.ROUND_CEILING); BigDecimal scaleWidth = standaraWeight.divide(width,4,BigDecimal.ROUND_CEILING); if (scaleHeight.compareTo(BigDecimal.valueOf(1)) == -1) { bufferedImage = Thumbnails.of(bufferedImage).scale(scaleHeight.floatValue()).outputQuality(1.0f).asBufferedImage(); calcScale(bufferedImage); }else if (scaleWidth.compareTo(BigDecimal.valueOf(1)) == -1) { bufferedImage = Thumbnails.of(bufferedImage).scale(scaleWidth.floatValue()).outputQuality(1.0f).asBufferedImage(); calcScale(bufferedImage); } } return bufferedImage; } }

5.PDF处理类 package JavaPdf; import com.itextpdf.text.*; import com.itextpdf.text.pdf.PdfPCell; import com.itextpdf.text.pdf.PdfPTable; import com.itextpdf.text.pdf.PdfWriter; import org.apache.pdfbox.util.PDFMergerUtility; import javax.imageio.ImageIO; import java.awt.color.ColorSpace; import java.awt.image.BufferedImage; import java.awt.image.ColorConvertOp; import java.io.ByteArrayOutputStream; import java.io.File; import java.io.FileOutputStream; import java.io.IOException; import java.util.Date; public class PdfUtil { /** * @Author Ragty * @Description 将图片转换为PDF * @Date 15:27 2019/3/4 * @return **/ public static String Img2PDF(String imagePath,BufferedImage img,String descfolder) throws Exception{ String pdfPath = ""; try { //图片操作 Image image = null; File file = new File(descfolder); if (!file.exists()){ file.mkdirs(); } pdfPath = descfolder +"/"+System.currentTimeMillis()+".pdf"; String type = imagePath.substring(imagePath.lastIndexOf(".")+1); Document doc = new Document(null, 0, 0, 0, 0); //更换图片图层 BufferedImage bufferedImage = new BufferedImage(img.getWidth(), img.getHeight(),BufferedImage.TYPE_3BYTE_BGR); bufferedImage.getGraphics().drawImage(img, 0,0, img.getWidth(), img.getHeight(), null); bufferedImage=new ColorConvertOp(ColorSpace.getInstance(ColorSpace.CS_GRAY),null).filter (bufferedImage,null); //图片流处理 doc.setPageSize(new Rectangle(bufferedImage.getWidth(), bufferedImage.getHeight())); System.out.println(bufferedImage.getWidth()+"()()()()()"+bufferedImage.getHeight()); ByteArrayOutputStream out = new ByteArrayOutputStream(); boolean flag = ImageIO.write(bufferedImage, type, out); byte[] b = out.toByteArray(); image = Image.getInstance(b); //写入PDF System.out.println("写入PDf:" + pdfPath); FileOutputStream fos = new FileOutputStream(pdfPath); PdfWriter.getInstance(doc, fos); doc.open(); doc.add(image); doc.close(); } catch (IOException e) { e.printStackTrace(); } catch (BadElementException e) { e.printStackTrace(); } catch (DocumentException e) { e.printStackTrace(); } return pdfPath; } /** * @Author Ragty * @Description 获取文件夹下的PDF * @Date 17:33 2019/3/7 * @return **/ private static String[] getFiles(String folder) throws IOException { File _folder = new File(folder); String[] filesInFolder; if (_folder.isDirectory()) { filesInFolder = _folder.list(); return filesInFolder; } else { throw new IOException("Path is not a directory"); } } /** * @Author Ragty * @Description 合成PDF * @Date 17:25 2019/3/7 * @return **/ public static void mergePDF(String[] files,String desfolder,String mergeFileName ) throws Exception{ PDFMergerUtility mergePdf = new PDFMergerUtility(); for (String file :files) { if (file.toLowerCase().endsWith("pdf")) mergePdf.addSource(file); } mergePdf.setDestinationFileName(desfolder+"/"+mergeFileName); mergePdf.mergeDocuments(); System.out.println("merge over"); } public static void main(String[] args) throws Exception{ ImgUtil imageUtil = new ImgUtil(); String[] files = new String[11]; files[0] = "D:/test2/2019021910311346.jpg"; files[1] = "D:/test2/2019021816284226.jpg"; files[2] = "D:/test2/2019021816284244.png"; files[3] = "D:/test2/2019021816284299.jpg"; files[4] = "D:/test2/2019021816284346.png"; files[5] = "D:/test2/2019021816285533.png"; files[6] = "D:/test2/2019021816285546.jpg"; files[7] = "D:/test2/2019021816285553.jpg"; files[8] = "D:/test2/2019021816285640.png"; files[9] = "D:/test2/2019021910305527.pdf"; files[10] = "D:/test2/201902191030445.pdf"; String folder = "D:/test2"; String mergeFileName = "final.pdf"; for (int i=0;i BufferedImage bi = imageUtil.rotateImage(file); if (bi==null) continue; String pdffile = Img2PDF(file,bi,folder); files[i] = pdffile; } } mergePDF(files,folder,mergeFileName); } }

7.测试

处理前在这里插入图片描述处理后的图片合并后的PDF

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