PDF 和 base64 的轉換

public static String PDFToBase64(File file) {
        BASE64Encoder encoder = new BASE64Encoder();
        FileInputStream fin = null;
        BufferedInputStream bin = null;
        ByteArrayOutputStream baos = null;
        BufferedOutputStream bout = null;
        try {
            fin = new FileInputStream(file);
            bin = new BufferedInputStream(fin);
            baos = new ByteArrayOutputStream();
            bout = new BufferedOutputStream(baos);
            byte[] buffer = new byte[1024];
            int len = bin.read(buffer);
            while (len != -1) {
                bout.write(buffer, 0, len);
                len = bin.read(buffer);
            }
            // 重新整理此輸出流並強制寫出所有緩衝的輸出位元組
            bout.flush();
            byte[] bytes = baos.toByteArray();
            return encoder.encodeBuffer(bytes).trim();

        } catch (FileNotFoundException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        } finally {
            // closeISStream(fin);
            closeISStream(bin);
            closeOSStream(bout);
        }
        return null;
    }

    public static void closeISStream(InputStream is) {
        if (is != null) {
            try {
                is.close();
            } catch (IOException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }
        }

    }

    public static void closeOSStream(OutputStream os) {
        if (os != null) {
            try {
                os.close();
            } catch (IOException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }
        }
    }

    public static void base64StringToPdf(String base64Content, String filePath) {
        BASE64Decoder decoder = new BASE64Decoder();
        BufferedInputStream bis = null;
        FileOutputStream fos = null;
        BufferedOutputStream bos = null;

        try {
            byte[] bytes = decoder.decodeBuffer(base64Content);// base64編碼內容轉換為位元組陣列
            ByteArrayInputStream byteInputStream = new ByteArrayInputStream(bytes);
            bis = new BufferedInputStream(byteInputStream);
            File file = new File(filePath);
            File path = file.getParentFile();
            if (!path.exists()) {
                path.mkdirs();
            }
            fos = new FileOutputStream(file);
            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);
            }

        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            // closeStream(bis, fos, bos);
            closeISStream(bis);
            closeOSStream(bos);
        }
    }