java实现PDF转图片-蒲公英云

java实现PDF转图片

此方法windows和linux都能用.

1,导依赖

<!-- https://mvnrepository.com/artifact/org.apache.pdfbox/pdfbox -->
<dependency>
    <groupId>org.apache.pdfbox</groupId>
    <artifactId>pdfbox</artifactId>
    <version>2.0.9</version>
</dependency>

上面依赖如果maven下载不了,那么就自己去maven官网下载jar包.

2,上代码

package com.export.diaojiekou.pdf_img;
import org.apache.pdfbox.pdmodel.PDDocument;
import org.apache.pdfbox.rendering.PDFRenderer;
import javax.imageio.ImageIO;
import java.awt.image.BufferedImage;
import java.io.File;
import java.io.IOException;
import java.util.ArrayList;
import java.util.List;
public class pdfToImgUtil {
    /**
     * pdf转图片
     * 转换全部的pdf
     * @param fileAddress PDF文件绝对路径
     * @return ArrayList<String>    生成imgs文件群的绝对路径集合
     */
    public static List<String> pdf2Img(String fileAddress) throws IOException {
        // 将pdf装图片 并且自定义图片得格式大小
        File file = new File(fileAddress);
        ArrayList<String> fileAddresss = new ArrayList<>();
        PDDocument doc = null;
        try {
            doc = PDDocument.load(file);
            PDFRenderer renderer = new PDFRenderer(doc);
            int pageCount = doc.getNumberOfPages();
            for (int i = 0; i < pageCount; i++) {
//经过测试,dpi为96,100,105,120,150,200中,105显示效果较为清晰,体积稳定,dpi越高图片体积越大,一般电脑显示分辨率为96
                BufferedImage image = renderer.renderImageWithDPI(i, 105); // Windows native DPI
                // BufferedImage srcImage = resize(image, 240, 240);//产生缩略图
                String substring = fileAddress.substring(0, fileAddress.lastIndexOf("."));
                ImageIO.write(image, "jpg", new File(substring + "_" + i + ".jpg"));
                fileAddresss.add(substring + "_" + i + ".jpg");
            }
        } catch (IOException e) {
            throw new IOException("pdf转img工具类异常");
        } finally {
            if (doc != null) {
                doc.close();
            }
        }
        return fileAddresss;
    }
    /**
     * 自由确定起始页和终止页
     *
     * @param fileAddress  文件绝对路径
     * @param indexOfStart 开始页  开始转换的页码，从0开始
     * @param indexOfEnd   结束页  停止转换的页码，
     */
    public static void pdf3Img(String fileAddress, int indexOfStart, int indexOfEnd) throws IOException {
        // 将pdf装图片 并且自定义图片得格式大小
        File file = new File(fileAddress);
        PDDocument doc = null;
        try {
            doc = PDDocument.load(file);
            PDFRenderer renderer = new PDFRenderer(doc);
            int pageCount = doc.getNumberOfPages();
            for (int i = indexOfStart; i < indexOfEnd; i++) {
                BufferedImage image = renderer.renderImageWithDPI(i, 105); // Windows native DPI
                // BufferedImage srcImage = resize(image, 240, 240);//产生缩略图
                String substring = fileAddress.substring(0, fileAddress.lastIndexOf("."));
                ImageIO.write(image, "jpg", new File(substring + "_" + (i + 1) + ".jpg"));
            }
        } catch (IOException e) {
            e.printStackTrace();
        }finally {
            if (doc != null) {
                doc.close();
            }
        }
    }
private static BufferedImage resize(BufferedImage source, int targetW,  int targetH) {
    int type=source.getType();
    BufferedImage target=null;
    double sx=(double)targetW/source.getWidth();
    double sy=(double)targetH/source.getHeight();
    if(sx>sy){
        sx=sy;
        targetW=(int)(sx*source.getWidth());
    }else{
        sy=sx;
        targetH=(int)(sy*source.getHeight());
    }
    if(type==BufferedImage.TYPE_CUSTOM){
        ColorModel cm=source.getColorModel();
        WritableRaster raster=cm.createCompatibleWritableRaster(targetW, targetH);
        boolean alphaPremultiplied=cm.isAlphaPremultiplied();
        target=new BufferedImage(cm,raster,alphaPremultiplied,null);
    }else{
        target=new BufferedImage(targetW, targetH,type);
    }
    Graphics2D g=target.createGraphics();
    g.setRenderingHint(RenderingHints.KEY_RENDERING, RenderingHints.VALUE_RENDER_QUALITY);
    g.drawRenderedImage(source, AffineTransform.getScaleInstance(sx, sy));
    g.dispose();
    return target;
}
}