KKFileView（十三）——文件操作

2021SC@SDUSC

前面几篇报告分别介绍了文件的预览以及文件的缓存，本次报告将概括介绍文件的具体操作，通过

FileHandlerService 类展开介绍

1、构造元素

logger	文件操作日志
DEFAULT_CONVERTER_CHARSET	默认转换字符
fileDir	默认文件地址
cacheService	缓存处理
uriEncoding	编码方式

2、文件基本操作

listConvertedFiles()	返回已转换过的文件集合(缓存)
getConvertedFile(String key)	已转换过的文件，根据文件名获取
getConvertedPdfImage(String key)	根据pdf本地路径 返回已将pdf转换成图片的图片本地相对路径
getFileNameFromPath(String path)	根据路径获得文件名
getRelativePath(String absolutePath)	根据绝对路径获得相对路径
addConvertedFile(String fileName, String value)	添加转换后的pdf缓存
addConvertedPdfImage(String pdfFilePath, int num)	添加pdf转图片的缓存
getImgCache(String fileKey)	获取redis中压缩包内图片文件
putImgCache(String fileKey, List<String> imgs)	设置redis中压缩包内图片文件
Map<String, String> listConvertedMedias()	已转换过的视频文件集合(缓存)
addConvertedMedias(String fileName, String value)	添加转换后的视频文件缓存
getConvertedMedias(String key)	已转换视频文件缓存，根据文件名获取

3、文件转换操作

1、对转换后的文件进行操作(改变编码方式)

 public void doActionConvertedFile(String outFilePath) {
        StringBuilder sb = new StringBuilder();
        try (InputStream inputStream = new FileInputStream(outFilePath);
             BufferedReader reader = new BufferedReader(new InputStreamReader(inputStream, DEFAULT_CONVERTER_CHARSET))) {
            String line;
            while (null != (line = reader.readLine())) {
                if (line.contains("charset=gb2312")) {
                    line = line.replace("charset=gb2312", "charset=utf-8");
                }
                sb.append(line);
            }
            // 添加sheet控制头
            sb.append("<script src=\"js/jquery-3.0.0.min.js\" type=\"text/javascript\"></script>");
            sb.append("<script src=\"js/excel.header.js\" type=\"text/javascript\"></script>");
            sb.append("<link rel=\"stylesheet\" href=\"bootstrap/css/bootstrap.min.css\">");
        } catch (IOException e) {
            e.printStackTrace();
        }
        // 重新写入文件
        try (FileOutputStream fos = new FileOutputStream(outFilePath);
             BufferedWriter writer = new BufferedWriter(new OutputStreamWriter(fos, StandardCharsets.UTF_8))) {
            writer.write(sb.toString());
        } catch (IOException e) {
            e.printStackTrace();
        }
    }

2、pdf文件转换成jpg图片集

public List<String> pdf2jpg(String pdfFilePath, String pdfName, String baseUrl) {
        List<String> imageUrls = new ArrayList<>();
        Integer imageCount = this.getConvertedPdfImage(pdfFilePath);
        String imageFileSuffix = ".jpg";
        String pdfFolder = pdfName.substring(0, pdfName.length() - 4);
        String urlPrefix;
        try {
            urlPrefix = baseUrl + URLEncoder.encode(pdfFolder, uriEncoding).replaceAll("\\+", "%20");
        } catch (UnsupportedEncodingException e) {
            logger.error("UnsupportedEncodingException", e);
            urlPrefix = baseUrl + pdfFolder;
        }
        if (imageCount != null && imageCount > 0) {
            for (int i = 0; i < imageCount; i++) {
                imageUrls.add(urlPrefix + "/" + i + imageFileSuffix);
            }
            return imageUrls;
        }
        try {
            File pdfFile = new File(pdfFilePath);
            PDDocument doc = PDDocument.load(pdfFile);
            int pageCount = doc.getNumberOfPages();
            PDFRenderer pdfRenderer = new PDFRenderer(doc);

            int index = pdfFilePath.lastIndexOf(".");
            String folder = pdfFilePath.substring(0, index);

            File path = new File(folder);
            if (!path.exists() && !path.mkdirs()) {
                logger.error("创建转换文件【{}】目录失败，请检查目录权限！", folder);
            }
            String imageFilePath;
            for (int pageIndex = 0; pageIndex < pageCount; pageIndex++) {
                imageFilePath = folder + File.separator + pageIndex + imageFileSuffix;
                BufferedImage image = pdfRenderer.renderImageWithDPI(pageIndex, 105, ImageType.RGB);
                ImageIOUtil.writeImage(image, imageFilePath, 105);
                imageUrls.add(urlPrefix + "/" + pageIndex + imageFileSuffix);
            }
            doc.close();
            this.addConvertedPdfImage(pdfFilePath, pageCount);
        } catch (IOException e) {
            logger.error("Convert pdf to jpg exception, pdfFilePath：{}", pdfFilePath, e);
        }
        return imageUrls;

3、cad文件转pdf

public boolean cadToPdf(String inputFilePath, String outputFilePath)  {
        Image cadImage = Image.load(inputFilePath);
        CadRasterizationOptions cadRasterizationOptions = new CadRasterizationOptions();
        cadRasterizationOptions.setLayouts(new String[]{"Model"});
        cadRasterizationOptions.setNoScaling(true);
        cadRasterizationOptions.setBackgroundColor(Color.getWhite());
        cadRasterizationOptions.setPageWidth(cadImage.getWidth());
        cadRasterizationOptions.setPageHeight(cadImage.getHeight());
        cadRasterizationOptions.setPdfProductLocation("center");
        cadRasterizationOptions.setAutomaticLayoutsScaling(true);
        cadRasterizationOptions.setDrawType(CadDrawTypeMode.UseObjectColor);
        PdfOptions pdfOptions = new PdfOptions();
        pdfOptions.setVectorRasterizationOptions(cadRasterizationOptions);
        File outputFile = new File(outputFilePath);
        OutputStream stream;
        try {
            stream = new FileOutputStream(outputFile);
            cadImage.save(stream, pdfOptions);
            cadImage.close();
            return true;
        } catch (FileNotFoundException e) {
            logger.error("PDFFileNotFoundException，inputFilePath：{}", inputFilePath, e);
            return false;
        }