流处理PDF、Base64

文件转Base64

public static String ImageToBase64ByLocal(String imgFile) {
    String pdfBase64 = "";
    try {
        byte[] pdfPathByte = Files.readAllBytes(Paths.get(imgFile));
        pdfBase64 = Base64.encodeBase64String(pdfPathByte);
    } catch (Exception e) {
        logger.info(e.getMessage(), e);
    }
    return pdfBase64;
}

Base64转文件

//方法一
String pngPath = path + fileName + ".PNG";
byte[] b = Base64Utils.decodeFromString(base64Str);
try (OutputStream out = new FileOutputStream(pngPath)) {
    out.write(b);
    out.flush();
} catch (Exception e) {
    System.out.println(e.getMessage());
}
//方法二
Files.write(Paths.get(filePath), Base64.decodeBase64(base64), StandardOpenOption.CREATE);

网络PDF地址转Base64

public static String pathToBase64(String strUrl) {
    String base64 = "";
    try {
        HttpURLConnection conn = null;
        try {
            URL url = new URL(strUrl);
            conn = (HttpURLConnection) url.openConnection();
            final ByteArrayOutputStream output = new ByteArrayOutputStream();
            IOUtils.copy(conn.getInputStream(), output);
            InputStream inputStream = new ByteArrayInputStream(output.toByteArray());

            ByteArrayOutputStream swapStream = new ByteArrayOutputStream();
            byte[] buff = new byte[100];
            int rc = 0;
            while ((rc = inputStream.read(buff, 0, 100)) > 0) {
                swapStream.write(buff, 0, rc);
            }
            byte[] in_b = swapStream.toByteArray();
            base64 = Base64Utils.encodeToString(in_b);
        } catch (Exception e) {
            log.error(e.getMessage(), e);
        } finally {
            try {
                if (conn != null) {
                    conn.disconnect();
                }
            } catch (Exception e) {
                log.error(e.getMessage(), e);
            }
        }
    } catch (Exception e) {
        e.printStackTrace();
    }

    return base64;
}

Base64转字节流

public static byte[] Base64strToByte(String base64str) {
    if (StringUtils.isEmpty(base64str)) {
        return null;
    }
    Base64.Decoder decoder = Base64.getDecoder();
    return decoder.decode(base64str);
}

字节流保存为PDF文件

public static void base64ByteToPdf(byte[] bytes, String filePath) {
    File file = new File(filePath);
    try (ByteArrayInputStream byteInputStream = new ByteArrayInputStream(bytes); BufferedInputStream bis = new BufferedInputStream(byteInputStream); FileOutputStream fos = new FileOutputStream(file); BufferedOutputStream bos = new BufferedOutputStream(fos);) {
        byte[] buffer = new byte[1024];
        int length = bis.read(buffer);
        while (length != -1) {
            bos.write(buffer, 0, length);
            length = bis.read(buffer);
        }
        bos.flush();
    } catch (Exception e) {
        e.printStackTrace();
    }
}

PNG Base64 转 PDF文件 转 PDF Base64

public static String PNGToPDF(String path, String fileName, String base64Str) {
    byte[] pngBase64 = Base64Utils.decodeFromString(base64Str);
    String pdfPath = path + fileName + ".pdf";
    com.lowagie.text.Document document = new com.lowagie.text.Document();
    try (FileOutputStream fos = new FileOutputStream(pdfPath)) {
        PdfWriter.getInstance(document, fos);
        // 读取一个图片
        Image image = Image.getInstance(pngBase64);
        float imageHeight = image.getScaledHeight();
        float imageWidth = image.getScaledWidth();
        // 设置文档的大小
        document.setPageSize(new RectangleReadOnly(imageWidth, imageHeight));
        document.open();
        image.setAbsolutePosition(0, 0);
        // 插入一个图片
        document.add(image);
        document.close();
        fos.flush();

        //PDF文件转Base64
        byte[] pdfPathByte = Files.readAllBytes(Paths.get(pdfPath));
        String pdfBase64 = Base64.encodeBase64String(pdfPathByte);

        return pdfBase64;
    } catch (Exception e) {
        System.out.println(e.getMessage());
    }

    return null;
}

导出文件

OutputStream out = response.getOutputStream();
try(InputStream inputStream = new FileInputStream(totalPdfPath)) {
    int b = 0;
    byte[] buffer = new byte[1024];
    while ((b = inputStream.read(buffer)) != -1) {
        out.write(buffer, 0, b);
    }
} catch (Exception e) {
    throw e;
}
out.flush();