多张图片合成转PDF工具类

1.需要导入的包

<dependency>
   <groupId>org.eclipse.birt.runtime.3_7_1</groupId>
   <artifactId>com.lowagie.text</artifactId>
   <version>2.1.7</version>
</dependency>
<dependency>
   <groupId>com.itextpdf</groupId>
   <artifactId>itextpdf</artifactId>
   <version>5.5.7</version>
</dependency>

2.工具类方法如下

package net.longjin.comm.utils;

import com.lowagie.text.Document;
import com.lowagie.text.Image;
import com.lowagie.text.Rectangle;
import com.lowagie.text.pdf.PdfWriter;

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

/**
 * 描述:多张图片转PDF
 *
 * @author 何志鹏
 * @ClassName:ImageToPdf
 * @create 2019-11-14 10:25
 * Version 1.0
 */
public class ImageToPdf {
    public static void toPdf(String imageFolderPath, String pdfPath) {
        try {
            // 图片地址
            String imagePath = null;
            // 输入流
            FileOutputStream fos = new FileOutputStream(pdfPath);
            // 创建文档
            Document doc = new Document(null, 0, 0, 0, 0);
            //doc.open();
            // 写入PDF文档
            PdfWriter.getInstance(doc, fos);
            // 读取图片流
            BufferedImage img = null;
            // 实例化图片
            Image image = null;
            // 获取图片文件夹对象
            File file = new File(imageFolderPath);
            File[] files = file.listFiles();
            // 循环获取图片文件夹内的图片
            for (File file1 : files) {
                if (file1.getName().endsWith(".png") || file1.getName().endsWith(".jpg") || file1.getName().endsWith(".gif")
                        || file1.getName().endsWith(".jpeg") || file1.getName().endsWith(".tif")) {
                    imagePath = imageFolderPath + file1.getName();
                    System.out.println(file1.getName());
                    // 读取图片流
                    img = ImageIO.read(new File(imagePath));
                    doc.setPageSize(new Rectangle(img.getWidth(), img
                            .getHeight()));
                    // 根据图片大小设置文档大小
                    doc.setPageSize(new Rectangle(img.getWidth(), img
                            .getHeight()));
                    // 实例化图片
                    image = Image.getInstance(imagePath);
                    // 添加图片到文档
                    doc.open();
                    doc.add(image);
                }
            }
            // 关闭文档
            doc.close();
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

    public static void main(String[] args) {
        long time1 = System.currentTimeMillis();
        toPdf("D:/photo/", "D:/photo.pdf");
        long time2 = System.currentTimeMillis();
        int time = (int) ((time2 - time1) / 1000);
        System.out.println("执行了：" + time + "秒！");
    }
}