//添加pdfbox的依赖

 compile('org.apache.pdfbox:pdfbox:2.0.7')

 <dependency>

   <groupId>org.apache.pdfbox</groupId>

   <artifactId>pdfbox</artifactId>

   <version>2.0.7</version>

 </dependency>

 package cn.apache.poi.pdf;

 import org.apache.pdfbox.io.RandomAccessBuffer;

 import org.apache.pdfbox.pdfparser.PDFParser;

 import org.apache.pdfbox.pdmodel.PDDocument;

 import org.apache.pdfbox.pdmodel.PDPage;

 import org.apache.pdfbox.rendering.PDFRenderer;

 import javax.imageio.IIOImage;

 import javax.imageio.ImageIO;

 import javax.imageio.ImageWriter;

 import javax.imageio.stream.ImageOutputStream;

 import java.awt.image.BufferedImage;

 import java.io.*;

 import java.util.Iterator;

 /**

  * Created by Jon_China on 2017/7/30.

  */

 public class Pdf2Image {

     public final  static String  IMG_TYPE_JPG = "jpg";

     public final  static String  IMG_TYPE_PNG = "png";

     public static void main( String[] args ) throws IOException{

         Pdf2Image pdf2Image = new Pdf2Image();

         pdf2Image.pdf2img("E:\\java测试\\java测试\\程序1\\待转换文件\\待转换pdf.pdf", "D:",IMG_TYPE_PNG);

     }

     /**

      * PDF转图片

      * @param pdfPath pdf文件的路径

      * @param savePath 图片保存的地址

      * @param imgType 图片保存方式

      */

     public void pdf2img(String pdfPath,String savePath,String imgType){

         String fileName = pdfPath.substring(pdfPath.lastIndexOf("\\")+1, pdfPath.length());

         fileName = fileName.substring(0,fileName.lastIndexOf("."));

         InputStream is = null;

         PDDocument pdDocument = null;

         try {

             is = new BufferedInputStream(new FileInputStream(pdfPath));

             //创建pdf文件解析器

             PDFParser parser = new PDFParser(new RandomAccessBuffer(is));

             parser.parse();

             //获取解析后的pdf文档

             pdDocument = parser.getPDDocument();

             //获取pdf渲染器，主要用来后面获取BufferedImage

             PDFRenderer renderer = new PDFRenderer(pdDocument);

             //获取pdf文件总页数

             int pageCount = pdDocument.getNumberOfPages();

             for (int i = 0; i < pageCount; i++) {

                 //构造保存文件名称格式

                 String saveFileName = savePath+"\\"+fileName+"-"+i+"."+imgType;

                 //获取当前页对象

                 PDPage page =  pdDocument.getPage(i);

                 //图片转换

                 pdfPage2Img(page,saveFileName,imgType,renderer,i);

             }

         } catch (Exception e) {

             e.printStackTrace();

         }finally{

             if(pdDocument != null){

                 try {

                     pdDocument.close();

                 } catch (IOException e) {

                     e.printStackTrace();

                 }

             }

         }

     }

     /**

      * 将pdf单页转换为图片

      * @param page 当页对象

      * @param saveFileName 保存的图片名称

      * @param imgType 保存的图片类型

      * @param renderer 用于获取BufferedImage

      * @param index 页索引

      * @throws IOException

      */

     public void pdfPage2Img(PDPage page,String saveFileName,String imgType,PDFRenderer renderer,int index) throws IOException{

         //构造图片

         BufferedImage img_temp  = renderer.renderImage(index);

         //设置图片格式

         Iterator<ImageWriter> it = ImageIO.getImageWritersBySuffix(imgType);

         //将文件写出

         ImageWriter writer = (ImageWriter) it.next();

         ImageOutputStream imageout = ImageIO.createImageOutputStream(new FileOutputStream(saveFileName));

         writer.setOutput(imageout);

         writer.write(new IIOImage(img_temp, null, null));

     }

 }