pdf图片处理

import cn.hutool.core.io.FileUtil;
import cn.hutool.http.HttpUtil;
import com.itextpdf.text.Document;
import com.itextpdf.text.DocumentException;
import com.itextpdf.text.PageSize;
import com.itextpdf.text.pdf.PdfWriter;
import com.zz.business.service.ImgPdfService;
import com.zz.framework.constant.AppConstant;
import com.zz.framework.constant.PageSizeConstant;
import com.zz.framework.enums.*;
import com.zz.framework.exception.BusinessException;
import com.zz.framework.utils.DocumentUtil;
import lombok.extern.slf4j.Slf4j;
import org.apache.commons.lang3.StringUtils;
import org.apache.pdfbox.pdmodel.PDDocument;
import org.apache.pdfbox.pdmodel.PDPageTree;
import org.apache.pdfbox.rendering.PDFRenderer;
import org.springframework.stereotype.Service;
import org.springframework.web.multipart.MultipartFile;

import javax.imageio.ImageIO;
import javax.imageio.stream.ImageOutputStream;
import javax.servlet.http.HttpServletResponse;
import java.awt.image.BufferedImage;
import java.io.*;
import java.util.ArrayList;
import java.util.List;
import java.util.zip.ZipEntry;
import java.util.zip.ZipOutputStream;

/**
 * 图片 pdf处理实现类
 *
 * @author Gao Zhengxing
 * @date 2022/5/18 0018 17:22
 */
@Service
@Slf4j
public class ImgPdfServiceImpl implements ImgPdfService {


    @Override
    public boolean uploadConvertPdf(HttpServletResponse response, MultipartFile[] files, int ratio, String paperSize) {
        response.reset();
        // 设置返回的请求ContentType
        response.setContentType(ContentTypeEnum.DOWNLOAD.getValue());
        // 设置返回的编码类型
        response.setCharacterEncoding(AppConstant.UTF_8);
        // 设置Content-disposition避免出现中文乱码
        response.setHeader(ResponseHeaderEnum.CONTENT_DISPOSITION.getCode(),
                ResponseHeaderEnum.CONTENT_DISPOSITION.getValue() + System.currentTimeMillis() + ".pdf");
        try {
            OutputStream ops = response.getOutputStream();
            //创建一个文档对象
            if (StringUtils.isEmpty(paperSize)) {
                paperSize = PageSizeConstant.A4;
            }
            Document doc = new Document(PageSize.getRectangle(paperSize));
            //定义输出文件的位置
            PdfWriter.getInstance(doc, ops);
            doc.open();
            for (MultipartFile file : files) {
                if (file.getBytes().length == 0) {
                    throw new BusinessException(StatusCode.UPLOAD_FORMAT_IS_EMPTY);
                }
                String originalFilename = file.getOriginalFilename();
                if (StringUtils.isBlank(originalFilename)) {
                    throw new BusinessException(StatusCode.UPLOAD_FORMAT_NO_NAME);
                }
                //文件后缀 带.
                String suffix = getSuffixAndFileName(file)[0];
                //文件格式 不带.
                String fileFormat = suffix.substring(1);
                boolean equalsDot = !SymbolEnum.DOT.getSymbol().equals(suffix.substring(0, 1));
                boolean equalsFileFormat = !FileFormatEnum.JPG.getFormat().equals(fileFormat) && !FileFormatEnum.PNG.getFormat().equals(fileFormat);
                if (equalsDot || equalsFileFormat) {
                    throw new BusinessException(StatusCode.INCORRECT_UPLOAD_FORMAT);
                }
                //默认A4大小
                DocumentUtil.docAddImg(doc, file.getBytes(), ratio);
            }
            // 关闭文档
            doc.close();
            //输出给调用方
            ops.flush();
        } catch (DocumentException e) {
            log.error("ReportServiceImpl#uploadConvertPdf pdf文档生成失败" + e);
            throw new BusinessException(StatusCode.PDF_DOC_HANDLE_EXCEPTION);
        } catch (IOException e) {
            handleFileIoException(e);
        }
        return true;
    }

    @Override
    public boolean webImgConvertPdf(HttpServletResponse response, List<String> imgList, int ratio, String paperSize) {
        response.reset();
        // 设置返回的请求ContentType
        response.setContentType(ContentTypeEnum.DOWNLOAD.getValue());
        // 设置返回的编码类型
        response.setCharacterEncoding(AppConstant.UTF_8);
        // 设置Content-disposition避免出现中文乱码
        response.setHeader(ResponseHeaderEnum.CONTENT_DISPOSITION.getCode(),
                ResponseHeaderEnum.CONTENT_DISPOSITION.getValue() + System.currentTimeMillis() + ".pdf");
        try {
            OutputStream ops = response.getOutputStream();
            //创建一个文档对象
            if (StringUtils.isEmpty(paperSize)) {
                paperSize = PageSizeConstant.A4;
            }
            Document doc = new Document(PageSize.getRectangle(paperSize));
            //定义输出文件的位置
            PdfWriter.getInstance(doc, ops);
            doc.open();
            for (String webPath : imgList) {
                //默认A4大小
                byte[] imgByte = HttpUtil.downloadBytes(webPath);
                DocumentUtil.docAddImg(doc, imgByte, ratio);
            }
            // 关闭文档
            doc.close();
            //输出给调用方
            ops.flush();
        } catch (DocumentException e) {
            log.error("ReportServiceImpl#webImgConvertPdf pdf文档生成失败" + e);
            throw new BusinessException(StatusCode.PDF_DOC_HANDLE_EXCEPTION);
        } catch (IOException e) {
            handleFileIoException(e);
        }
        return true;
    }

    private List<InputStream> flushImgList(String imgType, int pageCount, PDFRenderer pdfRenderer) {
        List<InputStream> list = new ArrayList<>();
        try {
            for (int i = 0; i < pageCount; i++) {
                BufferedImage image = pdfRenderer.renderImageWithDPI(i, 200);
                ByteArrayOutputStream os = new ByteArrayOutputStream();
                ImageIO.write(image, imgType, os);
                InputStream input = new ByteArrayInputStream(os.toByteArray());
                list.add(input);
            }
        } catch (IOException e) {
            log.error("转多张图片 IO处理失败" + e);
            throw new BusinessException(StatusCode.FILE_HANDLE_EXCEPTION);
        }
        return list;
    }

    private InputStream flushLongImg(String imgType, int pageCount, PDFRenderer pdfRenderer) {
        InputStream inputStream = null;
        try {
            inputStream = handleImg(pageCount, pdfRenderer, imgType);
        } catch (IOException e) {
            handleFileIoException(e);
        }
        return inputStream;
    }


    private void flushLongImg(HttpServletResponse response, String imgType, int pageCount, PDFRenderer pdfRenderer, String fileName) {
        if (FileFormatEnum.PNG.getFormat().equals(imgType)) {
            // 设置Content-disposition避免出现中文乱码
            response.setHeader(ResponseHeaderEnum.CONTENT_DISPOSITION.getCode(), ResponseHeaderEnum.CONTENT_DISPOSITION.getValue()
                    + fileName + "." + imgType);
        } else {
            // 设置Content-disposition避免出现中文乱码
            response.setHeader(ResponseHeaderEnum.CONTENT_DISPOSITION.getCode(), ResponseHeaderEnum.CONTENT_DISPOSITION.getValue()
                    + fileName + "." + FileFormatEnum.JPG.getFormat());
        }
        try {
            InputStream input = handleImg(pageCount, pdfRenderer, imgType);
            BufferedInputStream bis = new BufferedInputStream(input);
            byte[] buff = new byte[1024];
            OutputStream ops = response.getOutputStream();
            int i;
            while (true) {
                i = bis.read(buff);
                if (i == -1) {
                    break;
                }
                ops.write(buff, 0, i);
                ops.flush();
            }
        } catch (IOException e) {
            handleFileIoException(e);
        }
    }

    private InputStream handleImg(int pageCount, PDFRenderer pdfRenderer, String imgType) throws IOException {
        int[][] imageArrays = new int[pageCount][];
        List<BufferedImage> images = new ArrayList<>(pageCount);
        int dstHeight = 0;
        int dstWidth = 0;
        for (int i = 0; i < pageCount; i++) {
            BufferedImage image;
            image = pdfRenderer.renderImageWithDPI(i, 200);
            images.add(image);
            int width = image.getWidth();
            int height = image.getHeight();

            // 从图片中读取RGB 像素
            imageArrays[i] = new int[width * height];
            imageArrays[i] = image.getRGB(0, 0, width, height, imageArrays[i], 0, width);
            // 计算合并的宽度和高度
            dstWidth = Math.max(dstWidth, width);
            dstHeight += height;
        }
        // 合成图片像素
        if (dstHeight < 1) {
            log.info("ReportServiceImpl#flushLongImg: dstHeight < 1");
        }
        // 生成新图片
        BufferedImage imageNew = new BufferedImage(dstWidth, dstHeight, BufferedImage.TYPE_INT_RGB);
        int heightTotal = 0;
        for (int i = 0; i < images.size(); i++) {
            int width = images.get(i).getWidth();
            int height = images.get(i).getHeight();
            imageNew.setRGB(0, heightTotal, width, height, imageArrays[i], 0, width);
            heightTotal += height;
        }
        ByteArrayOutputStream os = new ByteArrayOutputStream();
        ImageIO.write(imageNew, imgType, os);
        return new ByteArrayInputStream(os.toByteArray());
    }

    private String[] getSuffixAndFileName(MultipartFile file) {
        String originalFilename = file.getOriginalFilename();
        if (StringUtils.isBlank(originalFilename)) {
            throw new BusinessException(StatusCode.UPLOAD_FORMAT_NO_NAME);
        }
        int length = originalFilename.length();
//      文件后缀 带.
        String suffix = originalFilename.substring(length - 4);
        String fileName = originalFilename.substring(0, length - 4);
        return new String[]{suffix, fileName};
    }

    @Override
    public boolean uploadConvertImg(HttpServletResponse response, MultipartFile file, String imgType,
                                    boolean longFlag) {
//      文件后缀 带.
        String suffix = getSuffixAndFileName(file)[0];
//      文件格式 不带.
        String fileFormat = suffix.substring(1);
        String fileName = getSuffixAndFileName(file)[1];
        if (suffix.substring(0, 1).equals(SymbolEnum.DOT.getSymbol()) && FileFormatEnum.PDF.getFormat().equals(fileFormat)) {
            try {
                byte[] byteArr = file.getBytes();
                bytesToImg(response, byteArr, imgType, fileName, longFlag);
            } catch (IOException e) {
                handleFileIoException(e);
            }
        } else {
            throw new BusinessException(StatusCode.INCORRECT_UPLOAD_FORMAT);
        }
        return true;
    }

    private void bytesToImg(HttpServletResponse response, byte[] byteArr, String imgType, String fileName, boolean longFlag) throws IOException {
        if (byteArr.length == 0) {
            throw new BusinessException(StatusCode.UPLOAD_FORMAT_IS_EMPTY);
        }
        InputStream stream = new ByteArrayInputStream(byteArr);
        // 加载解析PDF文件
        PDDocument doc = PDDocument.load(stream);
        PDFRenderer pdfRenderer = new PDFRenderer(doc);
        PDPageTree pages = doc.getPages();
        int pageCount = pages.getCount();
        response.reset();
        // 设置返回的请求ContentType
        response.setContentType(ContentTypeEnum.DOWNLOAD.getValue());
        // 设置返回的编码类型
        response.setCharacterEncoding(AppConstant.UTF_8);
        //pdf只有一页的时候
        if (1 == pageCount) {
            flushLongImg(response, imgType, pageCount, pdfRenderer, fileName);
        }
        //转长图
        else if (longFlag) {
            flushLongImg(response, imgType, pageCount, pdfRenderer, fileName);
        }
        //转多张图片压缩到一个zip
        else {
            flushZip(response, imgType, pageCount, pdfRenderer, fileName);
            log.info("文件压缩完成");
        }
    }


    @Override
    public boolean webPdfConvertImg(HttpServletResponse response, String pdfUrl, String fileName, String imgType, boolean longFlag) {
        try {
            //默认A4大小
            byte[] byteArr = HttpUtil.downloadBytes(pdfUrl);
            bytesToImg(response, byteArr, imgType, fileName, longFlag);
        } catch (IOException e) {
            handleFileIoException(e);
        }
        return true;
    }

    @Override
    public InputStream webPdfConvertImgStream(String pdfUrl, String fileName, String imgType, boolean longFlag) {
        InputStream inputStream = null;
        try {
            //默认A4大小
            byte[] byteArr = HttpUtil.downloadBytes(pdfUrl);
            if (byteArr.length == 0) {
                throw new BusinessException(StatusCode.UPLOAD_FORMAT_IS_EMPTY);
            }
            InputStream stream = new ByteArrayInputStream(byteArr);
            // 加载解析PDF文件
            PDDocument doc = PDDocument.load(stream);
            PDFRenderer pdfRenderer = new PDFRenderer(doc);
            PDPageTree pages = doc.getPages();
            int pageCount = pages.getCount();
            //pdf只有一页的时候
            if (1 == pageCount) {
                inputStream = flushLongImg(imgType, pageCount, pdfRenderer);
            }
            //转长图
            else if (longFlag) {
                inputStream = flushLongImg(imgType, pageCount, pdfRenderer);
            }
            //转多张图片压缩到一个zip
            else {
                inputStream = flushZip(imgType, pageCount, pdfRenderer, fileName);
                if (fileName.contains(SymbolEnum.DOT.getSymbol() + FileFormatEnum.ZIP.getFormat())) {
                    FileUtil.del(fileName);
                }
                log.info("文件压缩完成");
            }
        } catch (IOException e) {
            handleFileIoException(e);
        }
        return inputStream;
    }

    @Override
    public List<InputStream> webPdfConvertImgList(String pdfUrl, String imgType) {
        List<InputStream> fileInputStreamList = null;
        try {
            //默认A4大小
            byte[] byteArr = HttpUtil.downloadBytes(pdfUrl);
            if (byteArr.length == 0) {
                throw new BusinessException(StatusCode.UPLOAD_FORMAT_IS_EMPTY);
            }
            InputStream stream = new ByteArrayInputStream(byteArr);
            // 加载解析PDF文件
            PDDocument doc = PDDocument.load(stream);
            PDFRenderer pdfRenderer = new PDFRenderer(doc);
            PDPageTree pages = doc.getPages();
            int pageCount = pages.getCount();
            //转多张图片
            fileInputStreamList = flushImgList(imgType, pageCount, pdfRenderer);
        } catch (IOException e) {
            handleFileIoException(e);
        }
        return fileInputStreamList;
    }

    /**
     * 文件或文件夹压缩流
     *
     * @param out         输出流
     * @param imgType     图片类型
     * @param pageCount   页数
     * @param pdfRenderer pdf文件
     * @throws IOException io异常
     */
    private void zipFile(ZipOutputStream out, String imgType, int pageCount, PDFRenderer pdfRenderer) throws IOException {
        byte[] buf = new byte[1024];
        for (int i = 0; i < pageCount; i++) {
            BufferedImage img = pdfRenderer.renderImageWithDPI(i, 200);
            ByteArrayOutputStream bs = new ByteArrayOutputStream();
            ImageOutputStream imOut = ImageIO.createImageOutputStream(bs);
            if (FileFormatEnum.PNG.getFormat().equals(imgType)) {
                ImageIO.write(img, imgType, imOut);
            } else {
                ImageIO.write(img, FileFormatEnum.JPG.getFormat(), imOut);
            }
            InputStream inputStream = new ByteArrayInputStream(bs.toByteArray());
            if (FileFormatEnum.PNG.getFormat().equals(imgType)) {
                out.putNextEntry(new ZipEntry(i + "." + imgType));
            } else {
                out.putNextEntry(new ZipEntry(i + "." + FileFormatEnum.JPG.getFormat()));
            }
            int len;
            while ((len = inputStream.read(buf)) != -1) {
                out.write(buf, 0, len);
            }
        }
        out.closeEntry();
        out.close();
    }

    private FileInputStream flushZip(String imgType, int pageCount, PDFRenderer pdfRenderer, String fileName) {
        try {
            fileName = fileName.replace(".pdf", ".zip");
            OutputStream outputStream = new FileOutputStream(fileName);
            //文件或文件夹压缩流
            zipFile(new ZipOutputStream(outputStream), imgType, pageCount, pdfRenderer);
        } catch (IOException e) {
            handleFileIoException(e);
        }
        try {
            return new FileInputStream(fileName);
        } catch (FileNotFoundException e) {
            e.printStackTrace();
        }
        return null;
    }

    private void flushZip(HttpServletResponse response, String imgType, int pageCount, PDFRenderer
            pdfRenderer, String fileName) {
        // 设置Content-disposition避免出现中文乱码
        response.setHeader(ResponseHeaderEnum.CONTENT_DISPOSITION.getCode(), ResponseHeaderEnum.CONTENT_DISPOSITION.getValue() + fileName + ".zip");
        try {
            BufferedOutputStream bos = new BufferedOutputStream(response.getOutputStream());
            //文件或文件夹压缩流
            zipFile(new ZipOutputStream(bos), imgType, pageCount, pdfRenderer);
        } catch (IOException e) {
            handleFileIoException(e);
        }
    }

    private void handleFileIoException(IOException e) {
        log.error("IO处理失败" + e);
        throw new BusinessException(StatusCode.FILE_HANDLE_EXCEPTION);
    }

}