<dependency>
<groupId>com.itextpdf</groupId>
<artifactId>itextpdf</artifactId>
<version>5.5.13</version>
</dependency>
<dependency>
<groupId>com.itextpdf</groupId>
<artifactId>html2pdf</artifactId>
<version>4.0.3</version>
</dependency>
<dependency>
<groupId>org.apache.pdfbox</groupId>
<artifactId>pdfbox</artifactId>
<version>2.0.21</version>
</dependency>
<dependency>
<groupId>org.apache.pdfbox</groupId>
<artifactId>pdfbox-tools</artifactId>
<version>2.0.9</version>
</dependency>
原pdf为两页：
转成PNG图片：
转成两页合并后的pdf:
整体缩放后： 完美合并
代码：
//content为html模板填充后的html字符串数据 outpath为目标文件输出地址全路径
public static boolean html2Pdf(String content, String outPath) {
try {
ConverterProperties converterProperties = new ConverterProperties();
converterProperties.setCharset("UTF-8");
FontProvider fontProvider = new FontProvider();
fontProvider.addSystemFonts();
converterProperties.setFontProvider(fontProvider);
//关键合并
PdfDocument temp = new PdfDocument(new PdfWriter(new FileOutputStream(outPath)));
//根据数据最多的情况 调整合适大小
temp.setDefaultPageSize(PageSize.A0);
HtmlConverter.convertToPdf(content, temp, converterProperties);
File file = new File(outPath);
String ta = outPath.substring(0, outPath.lastIndexOf('.')) + "new.pdf";
int a = 20;
//转图片
//Pdf2Png.pdfFileToImage(file,ta,a);
//2页合并一页
//Pdf2Png.mergeTwoPagesIntoOne(outPath,ta);
//整体缩放pdf
String shrunkenPath = ta;
PdfWriter pdfWriter = new PdfWriter(shrunkenPath);
PdfDocument shrunkenDocument = new PdfDocument(pdfWriter);
String originalPath = outPath;
PdfReader pdfReader = new PdfReader(originalPath);
PdfDocument originalDocument= new PdfDocument(pdfReader);
PdfPage orignalPage= originalDocument.getPage(1);
Rectangle originalPDFSizes = orignalPage.getPageSize();
PdfPage emptyPage = shrunkenDocument.addNewPage();
Rectangle emptyPDFsizes= emptyPage.getPageSize();
double width = emptyPDFsizes.getWidth()/ originalPDFSizes.getWidth();
double height = emptyPDFsizes.getHeight() / originalPDFSizes.getHeight();
double newWidth = width / 2;
double newHeight = height / 2;
AffineTransform affineTransform = AffineTransform.getScaleInstance( newWidth, newHeight);
PdfCanvas canvas = new PdfCanvas(emptyPage);
canvas.concatMatrix(affineTransform);
PdfFormXObject pageCopy= orignalPage.copyAsFormXObject( shrunkenDocument);
canvas.addXObject(pageCopy, (float)newWidth, (float)newHeight);
Document doc = new Document(shrunkenDocument);
doc.close();
originalDocument.close();
} catch (Exception e) {
log.error("生成模板内容失败,{}",e);
return false;
}
return true;
}
工具类：
package com.haihu.common.utils.pdf;
import com.itextpdf.text.Document;
import com.itextpdf.text.DocumentException;
import com.itextpdf.text.RectangleReadOnly;
import com.itextpdf.text.pdf.PdfContentByte;
import com.itextpdf.text.pdf.PdfImportedPage;
import com.itextpdf.text.pdf.PdfReader;
import com.itextpdf.text.pdf.PdfWriter;
import org.apache.pdfbox.pdmodel.PDDocument;
import org.apache.pdfbox.rendering.PDFRenderer;
import javax.imageio.ImageIO;
import javax.imageio.stream.ImageOutputStream;
import java.awt.*;
import java.awt.image.BufferedImage;
import java.io.*;
import java.util.ArrayList;
import java.util.List;
/**
* @author 小于转暴雨??
* @date 2023/3/1 14:53
*/
public class Pdf2Png {
public static void main(String[] args) {
File file = new File("E:\git\hosp_front\public\view\20230216\张金妹.pdf");
String ta = "E:\git\hosp_front\public\view\20230216\张金妹.png";
int a = 20;
pdfFileToImage(file,ta,a);
}
public static void mergeTwoPagesIntoOne(String originalPdfFile, String outputPdfFile) throws IOException, DocumentException {
PdfReader reader = new PdfReader(originalPdfFile);
Document doc = new Document(new RectangleReadOnly(842f, 595f), 0, 0, 0, 0);
PdfWriter writer = PdfWriter.getInstance(doc, new FileOutputStream(outputPdfFile));
doc.open();
int totalPages = reader.getNumberOfPages();
for (int i = 1; i <= totalPages; i = i + 2) {
doc.newPage();
PdfContentByte cb = writer.getDirectContent();
PdfImportedPage page = writer.getImportedPage(reader, i); // page #1
float documentWidth = doc.getPageSize().getWidth() / 2;
float documentHeight = doc.getPageSize().getHeight();
if (i > 1)
documentHeight = documentHeight - 50f;
float pageWidth = page.getWidth();
float pageHeight = page.getHeight();
float widthScale = documentWidth / pageWidth;
float heightScale = documentHeight / pageHeight;
float scale = Math.min(widthScale, heightScale);
float offsetX = (documentWidth - (pageWidth * scale)) / 2;
float offsetY = 0f;
cb.addTemplate(page, scale, 0, 0, scale, offsetX, offsetY);
if (i+1 <= totalPages) {
PdfImportedPage page2 = writer.getImportedPage(reader, i+1); // page #2
pageWidth = page.getWidth();
pageHeight = page.getHeight();
widthScale = documentWidth / pageWidth;
heightScale = documentHeight / pageHeight;
scale = Math.min(widthScale, heightScale);
offsetX = ((documentWidth - (pageWidth * scale)) / 2) + documentWidth;
cb.addTemplate(page2, scale, 0, 0, scale, offsetX, offsetY);
}
}
doc.close();
}
/**
* pdf文件图像
* 这里的路径一定要具体到文件本身，不能直到文件夹，
* 如果只到文件夹会出现拒绝访问的错误，具体可以看上面main方法
*
* @param pdffile pdf路径
* @param targetPath 图片路径
* @param height_offset 高度
*/
public static void pdfFileToImage(File pdffile, String targetPath,int height_offset) {
try {
FileInputStream instream = new FileInputStream(pdffile);
InputStream byteInputStream = null;
try {
PDDocument doc = PDDocument.load(instream);
PDFRenderer renderer = new PDFRenderer(doc);
int pageCount = doc.getNumberOfPages();
List<BufferedImage> list = new ArrayList<BufferedImage>();
if (pageCount > 0) {
int totalHeight = 0;
int width = 0;
for (int i = 0; i < pageCount; i++) {
BufferedImage image = renderer.renderImage(i, 1.25f);
list.add(image);
totalHeight += image.getHeight();
if (width < image.getWidth()) {
width = image.getWidth();
}
image.flush();
}
BufferedImage tag = new BufferedImage(width, totalHeight, BufferedImage.TYPE_INT_RGB);
tag.getGraphics();
Graphics g = tag.createGraphics();
int startHeight = 0;
for (BufferedImage image : list) {
g.drawImage(image, 0, startHeight, width, image.getHeight(), null);
g.drawImage(image, 0, startHeight, width, image.getHeight(), null);
startHeight += image.getHeight() + height_offset;
}
g.dispose();
ByteArrayOutputStream bs = new ByteArrayOutputStream();
ImageOutputStream imOut;
imOut = ImageIO.createImageOutputStream(bs);
ImageIO.write(tag, "png", imOut);
byteInputStream = new ByteArrayInputStream(bs.toByteArray());
byteInputStream.close();
}
} catch (IOException e) {
e.printStackTrace();
}
File uploadFile = new File(targetPath);
FileOutputStream fops;
fops = new FileOutputStream(uploadFile);
fops.write(readInputStream(byteInputStream));
fops.flush();
fops.close();
} catch (Exception e) {
e.printStackTrace();
}
}
public static byte[] readInputStream(InputStream inStream) throws Exception {
ByteArrayOutputStream outStream = new ByteArrayOutputStream();
byte[] buffer = new byte[1024];
int len = 0;
while ((len = inStream.read(buffer)) != -1) {
outStream.write(buffer, 0, len);
}
inStream.close();
return outStream.toByteArray();
}
}