image2PDF

图片 转 pdf

使用poi和itext库实现。

maven 依赖

itext 依赖了 poi 不用手动添加

<dependencies>
<dependency>
    <groupId>com.itextpdf</groupId>
    <artifactId>io</artifactId>
    <version>7.2.0</version>
</dependency>
<dependency>
    <groupId>com.itextpdf</groupId>
    <artifactId>kernel</artifactId>
    <version>7.2.0</version>
</dependency>
<dependency>
    <groupId>com.itextpdf</groupId>
    <artifactId>layout</artifactId>
    <version>7.2.0</version>
</dependency>
<dependency>
    <groupId>com.itextpdf</groupId>
    <artifactId>itextpdf</artifactId>
    <version>5.5.9</version>
</dependency>
</dependencies>

工具实现

import com.itextpdf.io.image.ImageDataFactory;
import com.itextpdf.kernel.pdf.PdfDocument;
import com.itextpdf.kernel.pdf.PdfWriter;
import com.itextpdf.layout.Document;
import com.itextpdf.layout.element.Image;
import com.waysoft.modules.tools.FileUtil;

import java.io.ByteArrayOutputStream;
import java.io.File;


public class ImageToPdf implements Converter{

    private static ImageToPdf imageToPdf = null;

    private ImageToPdf(){}

    public static ImageToPdf create(){
        if(imageToPdf == null){
            imageToPdf = new ImageToPdf();
        }
        return imageToPdf;
    }

    @Override
    public byte[] convertToPdf(File imageFile) throws Exception {
        // FileUtil.readFileToByteArray(imageFile)  把 file 转为 btye[] 
        return convertToPdf(FileUtil.readFileToByteArray(imageFile));
    }

    @Override
    public byte[] convertToPdf(byte[] file) throws Exception {
        ByteArrayOutputStream outputStream = null;
        try {
            outputStream = new ByteArrayOutputStream();

            // 创建一个新的PDF文档
            PdfDocument pdfDoc = new PdfDocument(new PdfWriter(outputStream));

            // 创建一个文档对象
            Document document = new Document(pdfDoc);

            Image pdfImage = new Image(ImageDataFactory.create(file));
            document.add(pdfImage) ;

            document.close();
            return outputStream.toByteArray();
        }finally {
            outputStream.close();
        }
    }

}