pdf 提取图片

pdf 提取图片 ，提取的图片不是背景子图片。相当于把每一页pdf转换成图片

一共两种方法，

第一种提取速度较快 一秒几张。但是会丢失画质

第二种提取速度慢，两秒一张，但是不会丢失画质

------------------------------------------------------------------------

先说第一种

线上jar包

  <dependency> <groupId>org.apache.pdfbox</groupId>
  <artifactId>pdfbox</artifactId> <version>2.0.8</version> </dependency>
  
  <!-- https://mvnrepository.com/artifact/org.apache.pdfbox/pdfbox-tools -->
  <dependency> <groupId>org.apache.pdfbox</groupId>
  <artifactId>pdfbox-tools</artifactId> <version>2.0.8</version> </dependency>
  
  

/**
	 * 获得pdf的图片
	 * 
	 * @param pdfFilePath
	 *            如 C:\Users\TOSHIBA\Desktop\Helloworld.pdf
	 * @param imaDir
	 *            如 C:\Users\TOSHIBA\Desktop\
	 */
	public static void PDF2ImagByPdfBox(String pdfFilePath, String imaDir) {
		if (!pdfFilePath.endsWith("pdf") && !pdfFilePath.endsWith("PDF")) {
			throw new RuntimeException("不是pdf文件");
		}

		File pdfFile = new File(pdfFilePath);
		if (!pdfFile.exists()) {
			throw new RuntimeException("pdf文件不存在");
		}

		if (imaDir.charAt(imaDir.length() - 1) != '\') {
			imaDir += "\";
		}

		PDDocument pdf = null;
		try {
			pdf = PDDocument.load(new File(pdfFilePath));
			PDFRenderer pdfRenderer = new PDFRenderer(pdf);
			PDPageTree pageTree = pdf.getPages();
			int pageCounter = 0;
			for (PDPage page : pageTree) {
				float width = page.getCropBox().getWidth();
				float scale = 1.0f;
				if (width > 720) {
					scale = 720 / width;
				}
				BufferedImage bim = pdfRenderer.renderImage(pageCounter, scale,
						ImageType.RGB);
				ImageIOUtil.writeImage(bim, imaDir + (pageCounter++) + ".png",
						300);
			}
		} catch (IOException e) {
			e.printStackTrace();
		}
	}

-------------------------------------------------------------------------------------------------------------------------------

第二种

<dependency>
 <groupId>org.apache.pdfbox</groupId>
 <artifactId>pdfbox-app</artifactId>
 <version>2.0.2</version>
 </dependency>

/**
	 * @param pdfFilePath
	 *            如 C:\Users\TOSHIBA\Desktop\Helloworld.pdf
	 * @param imaDir
	 *            如 C:\Users\TOSHIBA\Desktop\
	 */
	public static void PDF2ImagByPdfBox(String pdfFilePath, String imaDir) {

		File file = new File(pdfFilePath);
		if (!pdfFilePath.endsWith("pdf") && !pdfFilePath.endsWith("PDF")) {
			throw new RuntimeException("不是pdf文件");
		}

		if (imaDir.charAt(imaDir.length() - 1) != '\') {
			imaDir += "\";
		}
		PDDocument doc=null;
		try {
			 doc = PDDocument.load(file);
			PDFRenderer renderer = new PDFRenderer(doc);
			int pageCount = doc.getNumberOfPages();
			for (int i = 0; i < pageCount; i++) {
				BufferedImage image = renderer.renderImageWithDPI(i, 296);
				ImageIO.write(image, "PNG", new File(imaDir + i + ".png"));
				System.out.println("转换页数" + i+ "----- "+ "总共页数"+ pageCount);
			}
		} catch (IOException e) {
			e.printStackTrace();
		}finally{
			try {
				if(null!=doc){
					doc.close();
				}
			} catch (Exception e2) {
				e2.printStackTrace();
			}
		}

	}