java实现pdf按页转换为图片

本文实例为大家分享了java实现pdf按页转换为图片的具体代码，供大家参考，具体内容如下

本程序是利用jacob.jar包实现的，关于jacob.jar的配置见我上一篇文章，程序中可配置参数选择图片清晰图。

package core.util;
 
import java.awt.image;
import java.awt.rectangle;
import java.awt.image.bufferedimage;
import java.io.file;
import java.io.filenotfoundexception;
import java.io.fileoutputstream;
import java.io.ioexception;
import java.io.randomaccessfile;
import java.lang.reflect.method;
import java.nio.mappedbytebuffer;
import java.nio.channels.filechannel;
import java.security.accesscontroller;
import java.security.privilegedaction;
 
import com.sun.image.codec.jpeg.jpegcodec;
import com.sun.image.codec.jpeg.jpegencodeparam;
import com.sun.image.codec.jpeg.jpegimageencoder;
import com.sun.pdfview.pdffile;
import com.sun.pdfview.pdfpage;
 
public class pdfchangtoimage {
 public static int changepdftoimg(string instructiopath,string picturepath) {
 int countpage =0;
 try {
 //instructiopath ="d:/instructio/2015-05-16/android 4编程入门经典.pdf"
 //picturepath = "d:/instructio/picture/2015-05-16/";
 
 file file = new file(instructiopath);
 randomaccessfile raf = new randomaccessfile(file, "r");
 filechannel channel = raf.getchannel();
 mappedbytebuffer buf = channel.map(filechannel.mapmode.read_only,
  0, channel.size());
 pdffile pdffile = new pdffile(buf);
 //创建图片文件夹
 file dirfile = new file(picturepath);
  if(!dirfile.exists()){
  dirfile.mkdirs();
 }
 //获得图片页数
 countpage = pdffile.getnumpages();
 for (int i = 1; i <= pdffile.getnumpages(); i++) {
 pdfpage page = pdffile.getpage(i);
 rectangle rect = new rectangle(0, 0, ((int) page.getbbox()
  .getwidth()), ((int) page.getbbox().getheight()));
 int n = 2;
 /** 图片清晰度（n>0且n<7）【pdf放大参数】 */
 image img = page.getimage(rect.width * n, rect.height * n,
  rect, /** 放大pdf到n倍，创建图片。 */
  null, /** null for the imageobserver */
  true, /** fill background with white */
  true /** block until drawing is done */
 );
 bufferedimage tag = new bufferedimage(rect.width * n,
  rect.height * n, bufferedimage.type_int_rgb);
 tag.getgraphics().drawimage(img, 0, 0, rect.width * n,
  rect.height * n, null);
 /**
  * file imgfile = new file("d:\\work\\mybook\\filesnew\\img\\" +
  * i + ".jpg"); if(imgfile.exists()){
  * if(imgfile.createnewfile()) { system.out.println("创建图片："+
  * "d:\\work\\mybook\\filesnew\\img\\" + i + ".jpg"); } else {
  * system.out.println("创建图片失败！"); } }
  */
 fileoutputstream out = new fileoutputstream(picturepath+"/" + i
  + ".png");
 /** 输出到文件流 */
 jpegimageencoder encoder = jpegcodec.createjpegencoder(out);
 jpegencodeparam param2 = encoder.getdefaultjpegencodeparam(tag);
 param2.setquality(1f, true);
 /** 1f~0.01f是提高生成的图片质量 */
 encoder.setjpegencodeparam(param2);
 encoder.encode(tag);
 /** jpeg编码 */
 out.close();
 }
 channel.close();
 raf.close();
 unmap(buf);
 /** 如果要在转图片之后删除pdf，就必须要这个关闭流和清空缓冲的方法 */
 } catch (filenotfoundexception e) {
 e.printstacktrace();
 } catch (ioexception e) {
 e.printstacktrace();
 }
 return countpage;
 
 }
 
 @suppresswarnings("unchecked")
 public static void unmap(final object buffer) {
 accesscontroller.doprivileged(new privilegedaction() {
 public object run() {
 try {
  method getcleanermethod = buffer.getclass().getmethod(
  "cleaner", new class[0]);
  getcleanermethod.setaccessible(true);
  sun.misc.cleaner cleaner = (sun.misc.cleaner) getcleanermethod
  .invoke(buffer, new object[0]);
  cleaner.clean();
 } catch (exception e) {
  e.printstacktrace();
 }
 return null;
 }
 });
 }
}

如果需要将word转pdf，也可参考我上一篇文章。