一、相关依赖包

 <dependency>
   <groupId>com.itextpdf</groupId>
   <artifactId>itextpdf</artifactId>
   <version>5.5.10</version>
</dependency>

<dependency>
   <groupId>com.itextpdf</groupId>
   <artifactId>itext-asian</artifactId>
   <version>5.2.0</version>
</dependency>  

二、创建相应的工具类

 import com.itextpdf.text.Document;
import com.itextpdf.text.Image;
import com.itextpdf.text.Paragraph;
import com.itextpdf.text.pdf.PdfWriter;
import org.springframework.stereotype.Component;

import javax.imageio.ImageIO;
import  java .awt.image.BufferedImage;
import java.io. File ;
import java.io.FileOutputStream;
import java.io.IOException;

@Component
public class ImageToPdfUtil {

    /**
     * 将图片转化为pdf
     * @param imageFolderPath
     * @param pdfPath
     */
    public  static   void  toPdf(String imageFolderPath, String pdfPath,String database) {
        //创建一个 文档 对象
        Document doc = new Document();
        try {
            // 输入流
             FileOutputStream  fos = new FileOutputStream(pdfPath);
            // 写入PDF文档
            PdfWriter writer = PdfWriter. getInstance (doc, fos);
            writer.setStrictImageSequence(true);

            //开启文档
            doc.open();
            // 获取图片文件夹对象
            File file = new File(imageFolderPath);
             if  (!file.getParentFile(). exists ())
                file.getParentFile().mkdirs();
            File[] files = file.listFiles();
            // 循环获取图片文件夹内的图片
            if (files != null && files.length > 0) {
                for (int i = 0; i < files.length; i++) {
                    File f = new File(imageFolderPath + i + ".png");
                    if (f.getName().endsWith(".png")
                            || f.getName().endsWith(".jpg")
                            || f.getName().endsWith(".gif")
                            || f.getName().endsWith(".jpeg")
                            || f.getName().endsWith(".tif")) {
                        String imagePath = imageFolderPath + f.getName();
                        // 实例化图片
                        Image image = Image.getInstance(imagePath);
                        //获得宽高
                        Float h = image.getHeight();
                        Float w = image.getWidth();
                        //统一压缩
                         Integer  percent = getPercent(h, w,i,database);
                        //图片居中
                        image.setAlignment(Image.MIDDLE);
                        //百分比显示图
                        image.scalePercent(percent);
                        // 添加图片到文档
                        doc.add(image);
                        // 换行,增加间距
                        doc.add(new Paragraph("n"));
                    }
                }
            }
            // 关闭文档
            doc.close();
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

    /**
     * 压缩
     * @param
     */
    public static Integer getPercent(Float h,Float w,int i,String database)
    {
        Float g2;
        if(" oracle ".equals(database)&&i==0){
            g2=580/w*100;
        }else{
            g2=800/w*100;
        }
        Integer g=Math.round(g2);
        return g;
    }

    /**
     * 将大图片切割为小图片
     */
    public static int cuttingImage(String imagePath,String outputPath,int indexPng) throws IOException {
        // 读取图片流
        BufferedImage img = ImageIO.read(new File(imagePath));
        //2105的a4纸的高度,count循环获取相应的位置
        int count=img.getHeight()%1420==0?img.getHeight()/1420:img.getHeight()/1420+1;
        for(int i=0;i<count;i++){
            int width = img.getWidth();
            int height = img.getHeight();
            //参数依次为，截取起点的x坐标，y坐标，截取宽度，截取高度
            BufferedImage pic2 = img.getSubimage(0, i*1420,
                    width, (i+1)*1420>height?height-i*1420:1420);
            //将截取的子图另行存储
            File desImage = new File(outputPath+(indexPng++)+".png");
            ImageIO.write(pic2, "png", desImage);
        }
        return indexPng;
    }
}