Java 下载网络资源文件

    public static void main(String[] args) throws IOException {
        String savePath = ".\\src\\main\\resources\\download";
        String path = "http://xxxxxx?xxxxxx.pdf";
        downLoadFromUrl(path, path.substring(path.lastIndexOf("?") + 1), savePath);
    }

    /**
     * 下载文件
     *
     * @param urlStr   文件路径
     * @param fileName 文件名
     * @param savePath 保存路径
     * @throws IOException
     */
    public static void downLoadFromUrl(String urlStr, String fileName, String savePath) throws IOException {
        URL url = new URL(urlStr);
        HttpURLConnection conn = (HttpURLConnection) url.openConnection();
        // 超时时间设置
        conn.setConnectTimeout(15 * 1000);
        InputStream inputStream = conn.getInputStream();
        byte[] getData = readInputStream(inputStream);
        //文件保存位置
        File saveDir = new File(savePath);
        if (!saveDir.exists()) {
            saveDir.mkdir();
        }
        File file = new File(saveDir + File.separator + fileName);
        FileOutputStream fos = new FileOutputStream(file);
        fos.write(getData);
        fos.close();
        inputStream.close();
        // 删除文件
        // boolean delFile = delFile(saveDir);
    }

    /**
     * 从输入流中获取字节数组
     *
     * @param inputStream
     * @return
     * @throws IOException
     */
    public static byte[] readInputStream(InputStream inputStream) throws IOException {
        byte[] buffer = new byte[1024];
        int len;
        ByteArrayOutputStream bos = new ByteArrayOutputStream();
        while ((len = inputStream.read(buffer)) != -1) {
            bos.write(buffer, 0, len);
        }
        bos.close();
        return bos.toByteArray();
    }

     /**
     * 删除文件
     *
     * @param file 文件
     * @return 成功->true 失败->false
     */
    public static boolean delFile(File file) {
        if (!file.exists()) {
            return false;
        }
        if (file.isDirectory()) {
            File[] files = file.listFiles();
            if (files != null && files.length > 0) {
                for (File f : files) {
                    delFile(f);
                }
            }
        }
        return file.delete();
    }