String pubOrderId = pageContext.getParameter("orderId");
StringBuffer l_buffer = new StringBuffer();
StringBuffer l_buffer1 = new StringBuffer();
l_buffer.append("javascript:mywin = openWindow(top, '");
l_buffer1.append("/jct/oracle/apps/xxpwc/entry/webui/AddAttachmentPG");
l_buffer1.append("&retainAM=Y");
l_buffer1.append("&pubOrderId="+pubOrderId);
String url = "/OA_HTML/OA.jsp?page="+l_buffer1.toString();
OAUrl popupUrl = new OAUrl(url, OAWebBeanConstants.ADD_BREAD_CRUMB_SAVE );
String strUrl = popupUrl.createURL(pageContext);
l_buffer.append(strUrl.toString());
l_buffer.append("', 'lovWindow', {width:750, height:550},false,'dialog',null);");
pageContext.putJavaScriptFunction("SomeName",l_buffer.toString());

Sample code from processFormRequest to pop up new window via javascript. worth noting: this is not recommended as it can break the OAF page.

OAF - Controller Code to create Javascript popup window

java, Oracle

Java