scala实现HighCharts生成的SVG图像下载

@WebServlet(name = "Highcharts-Chart-Export", urlPatterns = Array[String]("/svg"))
@MultipartConfig
@Singleton
class ExportSVGServlet extends HttpServlet with Disposable {
  val REQUEST_METHOD_POST = "POST"
  val CONTENT_TYPE_MULTIPART = "multipart/"
  val ORBIDDEN_WORD = "<!ENTITY"

  override def service(req: HttpServletRequest, res: HttpServletResponse) = {
    req.setCharacterEncoding("utf-8")
    res.setCharacterEncoding("utf-8")

    val multi = isMultipartRequest(req)
    val svg = getParameter(req, "svg", multi)
    val width = getParameter(req, "width", multi)
    val mime = getParameter(req, "type", multi)

    writeFileContentToHttpResponse(svg, "patent-analysis-imageexport-" + new SimpleDateFormat("yyyyMMddHHmmss").format(new Date()), if (width != null) width.toFloat else 0f, mime, res);
  }

  def writeFileContentToHttpResponse(svg: String,
    filename: String,  Float, mime: String,
    response: HttpServletResponse) = {

    var stream = new ByteArrayOutputStream()

    stream = SVGRasterizer.transcode(stream, svg, mime, width)

    response.reset()
    response.setContentLength(stream.size())
    response.setCharacterEncoding("utf-8")
    response.setHeader("Content-disposition", "attachment; filename=" + filename + {
      mime.toLowerCase() match {
        case "image/png" => ".png"
        case "image/jpeg" => ".jpg"
        case "application/pdf" => ".pdf"
        case _ => mime.toLowerCase()
      }
    })
    response.setHeader("Content-type", mime)
    using(response.getOutputStream()) { out => out.write(stream.toByteArray()) }
  }

  def isMultipartRequest(request: HttpServletRequest) = REQUEST_METHOD_POST.equalsIgnoreCase(request.getMethod()) && request.getContentType() != null && request.getContentType().toLowerCase().startsWith(CONTENT_TYPE_MULTIPART)

  private def getParameter(request: HttpServletRequest, name: String, multi: Boolean) = {
    if (multi && request.getPart(name) != null) {
      getValue(request.getPart(name));
    } else {
      request.getParameter(name);
    }
  }

  private def getValue(part: Part) =Source.fromInputStream(part.getInputStream(), "utf-8").mkString

  def getFilename(name: String) = if (name != None) name else "chart"
}