java pdf 多页转换为png格式的图片

喜欢ヅ旅行 2022-12-27 06:23 155阅读 0赞

java pdf 多页转换为png格式的图片  适用于 无论pdf有多少页均可

废话不说，直接上代码

import java.awt.Graphics;
    import java.awt.image.BufferedImage;
    import java.io.ByteArrayInputStream;
    import java.io.ByteArrayOutputStream;
    import java.io.File;
    import java.io.FileInputStream;
    import java.io.FileOutputStream;
    import java.io.IOException;
    import java.io.InputStream;
    import java.util.ArrayList;
    import java.util.List;
    
    import javax.imageio.ImageIO;
    import javax.imageio.stream.ImageOutputStream;
    
    import org.apache.pdfbox.pdmodel.PDDocument;
    import org.apache.pdfbox.rendering.PDFRenderer;
    
    /**
     * 
     * @author wdg pdf 转换为pdf
     *
     */
    public class PdfToPng {
    	
    	
    	/***
    	 * 
    	 * 
    	 *   使用方式
    	 *   
    	 *   maven 项目中需要引入:
    	 *   <dependency>
    			<groupId>org.apache.pdfbox</groupId>
    			<artifactId>pdfbox</artifactId>
    			<version>2.0.21</version>
    		</dependency>
    	 *   
    	 *   
    	 *   
    	 * 方法是将多张pdf 转换为png 格式的图片
    	 * @param pdffile  pdf 文件路径
    	 * @param targetPath  png 文件存储路径
    	 * @param height_offset  多张图片之间合成间隔距离
    	 */
    
    
    	public static void pdfFileToImage(File pdffile, String targetPath,int height_offset) {
    		try {
    			FileInputStream instream = new FileInputStream(pdffile);
    			InputStream byteInputStream = null;
    			try {
    				PDDocument doc = PDDocument.load(instream);
    				PDFRenderer renderer = new PDFRenderer(doc);
    				int pageCount = doc.getNumberOfPages();
    				List<BufferedImage> list = new ArrayList<BufferedImage>();
    				if (pageCount > 0) {
    
    					int totalHeight = 0;
    					int width = 0;
    
    					for (int i = 0; i < pageCount; i++) {
    						BufferedImage image = renderer.renderImage(i, 1.25f);
    						list.add(image);
    						totalHeight += image.getHeight();
    						if (width < image.getWidth()) {
    							width = image.getWidth();
    						}
    						image.flush();
    					}
    
    					BufferedImage tag = new BufferedImage(width, totalHeight, BufferedImage.TYPE_INT_RGB);
    
    					tag.getGraphics();
    
    					Graphics g = tag.createGraphics();
    
    					int startHeight = 0;
    					for (BufferedImage image : list) {
    						g.drawImage(image, 0, startHeight, width, image.getHeight(), null);
    						g.drawImage(image, 0, startHeight, width, image.getHeight(), null);
    						startHeight += image.getHeight() + height_offset;
    					}
    					g.dispose();
    
    					ByteArrayOutputStream bs = new ByteArrayOutputStream();
    					ImageOutputStream imOut;
    					imOut = ImageIO.createImageOutputStream(bs);
    					ImageIO.write(tag, "png", imOut);
    					byteInputStream = new ByteArrayInputStream(bs.toByteArray());
    					byteInputStream.close();
    
    				}
    			} catch (IOException e) {
    				e.printStackTrace();
    			}
    
    			File uploadFile = new File(targetPath);
    			FileOutputStream fops;
    			fops = new FileOutputStream(uploadFile);
    			fops.write(readInputStream(byteInputStream));
    			fops.flush();
    			fops.close();
    
    		} catch (Exception e) {
    			e.printStackTrace();
    		}
    	}
    
    	public static byte[] readInputStream(InputStream inStream) throws Exception {
    		ByteArrayOutputStream outStream = new ByteArrayOutputStream();
    		byte[] buffer = new byte[1024];
    		int len = 0;
    		while ((len = inStream.read(buffer)) != -1) {
    			outStream.write(buffer, 0, len);
    		}
    		inStream.close();
    		return outStream.toByteArray();
    	}
    
    	public static void main(String[] args) {
    		File file = new File("D:\\pdfpath\\ceshi2.pdf");
    		// 上传的是png格式的图片结尾
    		String targetfile = "D:\\pdfpath\\wdg3.png";
    		
    		pdfFileToImage(file, targetfile,10);
    	}
    
    }

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