Java PDF 转图片

分手后的思念是犯贱 2022-06-05 03:46 249阅读 0赞

package com.hbzx.utils;
    
    import java.awt.image.BufferedImage;
    import java.io.File;
    import java.io.IOException;
    import java.util.ArrayList;
    import java.util.List;
    
    import org.apache.pdfbox.pdmodel.PDDocument;
    import org.apache.pdfbox.pdmodel.PDPage;
    import org.apache.pdfbox.pdmodel.encryption.InvalidPasswordException;
    import org.apache.pdfbox.rendering.ImageType;
    import org.apache.pdfbox.rendering.PDFRenderer;
    import org.apache.pdfbox.tools.imageio.ImageIOUtil;
    import org.junit.Test;
    
    public class PDFToJpg {
    
    	@Test
    	public void pdfToJpg() throws InvalidPasswordException, IOException {
    		String pdfFilename = "C:\\Users\\aimil\\Desktop\\2.pdf";
    		PDDocument document = PDDocument.load(new File(pdfFilename));
    		PDFRenderer pdfRenderer = new PDFRenderer(document);
    		List<BufferedImage> images = new ArrayList<>();
    		int pageCounter = 0;
    		for (PDPage page : document.getPages()) {
    			// note that the page number parameter is zero based
    			BufferedImage bim = pdfRenderer.renderImageWithDPI(pageCounter++, 300, ImageType.RGB);
    			images.add(bim);
    		}
    		
    		BufferedImage result = mergeImage(false,images.toArray(new BufferedImage[0]));
    		ImageIOUtil.writeImage(result, pdfFilename + "-" + (pageCounter++) + ".png", 300);
    		document.close();
    	}
    
    	/**
    	 * 合并任数量的图片成一张图片
    	 * 
    	 * @param isHorizontal
    	 *            true代表水平合并，fasle代表垂直合并
    	 * @param imgs
    	 *            欲合并的图片数组
    	 * @return
    	 * @throws IOException
    	 */
    	public static BufferedImage mergeImage(boolean isHorizontal, BufferedImage... imgs) throws IOException {
    		// 生成新图片
    		BufferedImage destImage = null;
    
    		// 计算新图片的长和高
    		int allw = 0, allh = 0, allwMax = 0, allhMax = 0;
    		for (BufferedImage img : imgs) {
    			allw += img.getWidth();
    			allh += img.getHeight();
    			if (img.getWidth() > allwMax) {
    				allwMax = img.getWidth();
    			}
    			if (img.getHeight() > allhMax) {
    				allhMax = img.getHeight();
    			}
    		}
    		// 创建新图片
    		if (isHorizontal) {
    			destImage = new BufferedImage(allw, allhMax, BufferedImage.TYPE_INT_RGB);
    		} else {
    			destImage = new BufferedImage(allwMax, allh, BufferedImage.TYPE_INT_RGB);
    		}
    
    		// 合并所有子图片到新图片
    		int wx = 0, wy = 0;
    		for (int i = 0; i < imgs.length; i++) {
    			BufferedImage img = imgs[i];
    			int w1 = img.getWidth();
    			int h1 = img.getHeight();
    			// 从图片中读取RGB
    			int[] ImageArrayOne = new int[w1 * h1];
    			ImageArrayOne = img.getRGB(0, 0, w1, h1, ImageArrayOne, 0, w1); // 逐行扫描图像中各个像素的RGB到数组中
    			if (isHorizontal) { // 水平方向合并
    				destImage.setRGB(wx, 0, w1, h1, ImageArrayOne, 0, w1); // 设置上半部分或左半部分的RGB
    			} else { // 垂直方向合并
    				destImage.setRGB(0, wy, w1, h1, ImageArrayOne, 0, w1); // 设置上半部分或左半部分的RGB
    			}
    			wx += w1;
    			wy += h1;
    		}
    		return destImage;
    	}
    }