Java PDF 转图片-蒲公英云

Java PDF 转图片

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;
    }
}