将pdf按照页数转化为图片

需要用到的jar包 jacob-1.14.3.jar、 pdfrenderer-0.9.1-patched.jar

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;  
            }  
        });  
    }  
}  

在这里面可能会遇到一个错误 import com.sun.image.codec.jpeg.JPEGCodec;
import com.sun.image.codec.jpeg.JPEGEncodeParam;
import com.sun.image.codec.jpeg.JPEGImageEncoder;
映入这几个rt.jar导入不进去，需要设置的地方是