java使用浏览器请求下载pdf文件

代码

/**
 * 下载pdf文件
 *
 * @param pdfFileUrl 文件地址
 * @param fileName   文件名称
 */
public static void downloadPdf(String pdfFileUrl, String fileName) {

    ServletRequestAttributes requestAttributes = (ServletRequestAttributes) RequestContextHolder
            .getRequestAttributes();

    if (null == requestAttributes) {
        throw new RuntimeException("请求失败");
    }
    HttpServletResponse response = requestAttributes.getResponse();

    ServletOutputStream outputStream = null;
    InputStream inputStream = null;

    try {
        // 获取网络文件
        URL urlFile = new URL(pdfFileUrl);
        HttpURLConnection conn = (HttpURLConnection) urlFile.openConnection();
        conn.setRequestMethod("GET");
        conn.setConnectTimeout(5 * 1000);

        // 通过输入流获取图片数据
        inputStream = conn.getInputStream();

        // 文件类型
        response.setContentType("application/pdf");
        // 设置请求头
        response.setHeader("Content-Disposition", "attachment; filename=" + URLEncoder.encode(fileName, "UTF-8"));

        // 获取输出流
        outputStream = response.getOutputStream();
        byte[] buffer = new byte[1024];
        int len;
        while( (len = inputStream.read(buffer)) != -1 ){
            outputStream.write(buffer, 0, len);
        }

        outputStream.flush();
    } catch (Exception e) {
        log.error("【下载PDF文件失败】原因：{}", e.getMessage());
        e.printStackTrace();
    } finally {
        try {
            if (null != inputStream) {
                inputStream.close();
            }
            if (null != outputStream) {
                outputStream.close();
            }
        } catch (Exception ignored) {}
    }
}