Retrieve file from the database

good morning,

I want to recover a file that I have saved in the database, I have it in bytes, but I do not know how I can recover it, I want that pressing a button that file is downloaded to a local folder.

This is the code I use to upload it to the BD:

HTML:

<div class="form-group">
    <label class="col-sm-2 control-label">Archivo:</label>
    <div class="col-sm-10">
     <div id="dadjunto1" class="input-group">
       <input type="text" id="txtFile1" name="txtFile1" class="form-control required" style="margin-left:10px" readonly="readonly" />
         <div class="input-group-btn">
<label class="btn btn-primary">
   <span aria-hidden="true">SELECCIONAR ARCHIVO</span>
     <input type="file" id="adjunto1" name="adjunto1" style="display:none" onchange="$('input[name=\'txtFile1\']').val($('input[name=\'adjunto1\']').val().replace(/C:\fakepath\/i, '')).trigger('change'); return false;"/>
      </label>
    </div>
  </div>
  </div>
 </div>

Servlet:

        protected void doPost(HttpServletRequest request,HttpServletResponse 
             response) throws ServletException, IOException {
               byte[] archivobyte= archivo.obtenerBytes(request );
               //Guardo archivobyte en la base de datos
         }

Class file:

 public static byte[] obtenerBytes(HttpServletRequest request ) {
      byte[] fileArray = new byte[1024];
      DiskFileItemFactory factory = new DiskFileItemFactory();
      factory.setRepository(new File(System.getProperty("java.io.tmpdir")));
      ServletFileUpload upload = new ServletFileUpload(factory);
      List formItems = upload.parseRequest(request);
      if (formItems != null && formItems.size() > 0) {
          for (Object item : formItems){
              FileItem uploaded = (FileItem) item;
              if (!uploaded.isFormField()) {
                    InputStream input = uploaded.getInputStream();
                    input.read(fileArray);
                }
          }
      }
   return fileArray;
 }